LIGNOPHYTA

Plant a shrub or tree; true roots +, origin endogeneous, root cap +, apex multicellular; endodermis +; shoot apical meristem multicellular; lateral meristems +, cork cambium producing cork abaxially, vascular cambium producing phloem abaxially and xylem adaxially; lamina with mean venation density 1.8 mm/mm² (to 5 mm/mm²).

EXTANT SEED PLANTS/SPERMATOPHYTA

Plant woody, evergreen; nicotinic acid metabolised to trigonelline, (cyanogenesis via tyrosine pathway); primary cell walls rich in xyloglucans and/or glucomannans, 25-30% pectin [Type I walls]; lignins derived from (some) sinapyl and particularly coniferyl alcohols, thus containing p-hydroxyphenyl and guaiacyl lignin units, so no Maüle reaction; root xylem exarch, cork cambium deep seated; arbuscular mycorrhizae +; shoot apical meristem interface specific plasmodesmatal network; stem with vascular tissue around central pith [eustele], vascular bundles with interfascicular tissue, ectophloic, endodermis 0, xylem endarch; wood homoxylous, tracheids and rays alone, tracheid/tracheid pits circular, bordered; mature sieve tube/cell lacking functioning nucleus, sieve tube plastids with starch grains; phloem fibres +; stem cork cambium superficial; branches exogenous; leaves with single trace from vascular sympodium ["nodes 1:1"]; vascular bundles collateral [stem: phloem external; leaf: phloem abaxial]; stomata morphology?, pore opening controlled by abscisic acid; leaves with petiole and lamina, spiral, development basipetal, blade simple; axillary buds +, not associated with all leaves; prophylls two, lateral; plant heterosporous, sporangia borne on sporophylls; microsporophylls aggregated in indeterminate cones/strobili; true pollen +, grains mono[ana]sulcate, exine and intine homogeneous; ovules unitegmic, parietal tissue 2+ cells across, megaspore tetrad tetrahedral, only one megaspore develops, megasporangium indehiscent; male gametophyte development first endo- then exosporic, tube developing from distal end of grain, to ca 2 mm from receptive surface to egg, gametes two, developing after pollination, with cell walls, flagellae numerous; ovules increasing considerably in size between pollination and fertilization, female gametophyte endosporic, initially syncytial, walls then surrounding individual nuclei; seeds "large" [ca 8 mm³], but not much bigger than ovule, with morphological dormancy; embryo cellular ab initio, endoscopic, plane of first cleavage of zygote transverse, suspensor +, short-minute, embryo straight, shoot and root at opposite ends [allorrhizic], white, cotyledons 2; plastid transmission maternal; ycf2 gene in inverted repeat, two copies of LEAFY gene, PHY gene duplications [three - [BP [A/N + C/O]] - copies], nrDNA with 5.8S and 5S rDNA in separate clusters; mitochondrial nad1 intron 2 and coxIIi3 intron and trans-spliced introns present.

MAGNOLIOPHYTA

Lignans, O-methyl flavonols, dihydroflavonols, triterpenoid oleanane, non-hydrolysable tannins, quercetin and/or kaempferol +, apigenin and/or luteolin scattered, [cyanogenesis in ANITA grade?], S [syringyl] lignin units common, positive Maüle reaction [syringyl:guaiacyl ratio more than 2-2.5:1], and hemicelluloses as xyloglucans; root apical meristem intermediate-open; root vascular tissue oligarch [di- to pentarch], lateral roots arise opposite or immediately to the side of [when diarch] xylem poles; origin of epidermis with no clear pattern [probably from inner layer of root cap], trichoblasts [differentiated root hair-forming cells] 0, exodermis +; shoot apex with tunica-corpus construction, tunica 2-layered; reaction wood ?, associated gelatinous fibres [g-fibres] with innermost layer of secondary cell wall rich in cellulose and poor in lignin; starch grains simple; primary cell wall mostly with pectic polysaccharides, poor in mannans; tracheid:tracheid [end wall] plates with scalariform pitting, wood parenchyma +; sieve tubes enucleate, sieve plate with pores (0.1-)0.5-10< µm across, cytoplasm with P-proteins, cytoplasm not occluding pores of sieve plate, companion cell and sieve tube from same mother cell; sugar transport in phloem passive; nodes unilacunar [1:?]; stomata brachyparacytic [ends of subsidiary cells level with ends of pore], outer stomatal ledges producing vestibule; lamina formed from the primordial leaf apex, margins toothed, development of venation acropetal, secondary veins pinnate, overall growth ± diffuse, venation hierarchical, fine venation reticulate, veins (1.7-)4.1(-5.7) mm/mm², endings free; most/all leaves with axillary buds; flowers perfect, pedicellate, ± haplomorphic, parts spiral [esp. the A], free, numbers unstable, development in general centripetal; P not sharply differentiated, with a single trace, outer members not enclosing the rest of the bud, often smaller than inner members; A many, filament not sharply distinguished from anther, stout, broad, with a single trace, anther introrse, tetrasporangiate, sporangia in two groups of two [dithecal], ± embedded in the filament, with at least outer secondary parietal cells dividing, each theca dehiscing longitudinally, endothecium +, endothecial cells elongated at right angles to long axis of anther; tapetum glandular, cells binucleate; microspore mother cells in a block, microsporogenesis successive, walls developing by centripetal furrowing; pollen subspherical, tectum continuous or microperforate, ektexine columellar, endexine thin, compact, lamellate only in the apertural regions; nectary 0; G superior, free, several, ascidiate, with postgenital occlusion by secretion, stylulus short, hollow, cavity not lined by distinct epidermal layer, stigma ± decurrent, dry [not secretory]; ovules few [?1]/carpel, marginal, anatropous, bitegmic, micropyle endostomal, outer integument 2-3 cells across, often largely subdermal in origin, inner integument 2-3 cells across, often dermal in origin, parietal tissue 1-3 cells across [crassinucellate], nucellar cap?; megasporocyte single, hypodermal, megaspore tetrad linear, functional megaspore chalazal, lacking sporopollenin and cuticle; female gametophyte four-celled [one module, nucleus of egg cell sister to one of the polar nuclei]; ovule not increasing in size between pollination and fertilization; pollen binucleate at dispersal, male gametophyte trinucleate, germinating in less than 3 hours, pollination siphonogamous, tube elongated, growing between cells, growth rate 20-20,000 µm/hour, outer wall pectic, inner wall callose, with callose plugs, penetration of ovules via micropyle [porogamous], whole process takes ca 18 hours, distance to first ovule 1.1-2.1 mm; male gametes lacking cell walls, flagellae 0, double fertilization +, ovules aborting unless fertilized; P deciduous in fruit; seed exotestal, becoming much larger than ovule at time of fertilization; endosperm diploid, cellular [micropylar and chalazal domains develop differently, first division oblique, micropylar end initially with a single large cell, divisions uniseriate, chalazal cell smaller, divisions in several planes], copious, oily and/or proteinaceous; embryogenesis cellular; germination hypogeal, seedlings/young plants sympodial; Arabidopsis-type telomeres [(TTTAGGG)_n]; whole genome duplication, ndhB gene 21 codons enlarged at the 5' end, single copy of LEAFY and RPB2 gene, knox genes extensively duplicated [A1-A4], AP1/FUL gene, paleo AP3 and PI genes [paralogous B-class genes] +, with "DEAER" motif, SEP3/LOFSEP and three copies of the PHY gene, [PHYB [PHYA + PHYC]].

[NYMPHAEALES [AUSTROBAILEYALES [[CHLORANTHALES + MAGNOLIIDS] [MONOCOTS [CERATOPHYLLALES + EUDICOTS]]]]]: vessels +, elements with elongated scalariform perforation plates; wood fibres +; axial parenchyma diffuse or diffuse-in-aggregates; pollen monosulcate [anasulcate], tectum reticulate-perforate [here?]; ?genome duplication; "DEAER" motif in AP3 and PI genes lost, gaps in these genes.

[AUSTROBAILEYALES [[CHLORANTHALES + MAGNOLIIDS] [MONOCOTS [CERATOPHYLLALES + EUDICOTS]]]]: essential oils in specialized cells [lamina and P ± pellucid-punctate]; tension wood 0; tectum reticulate; anther wall with outer secondary parietal cell layer dividing; carpels plicate; nucellar cap + [character lost where in eudicots?]; 12BP [4 amino acids] deletion in P1 gene.

[[CHLORANTHALES + MAGNOLIIDS] [MONOCOTS [CERATOPHYLLALES + EUDICOTS]]] / MESANGIOSPERMAE: benzylisoquinoline alkaloids +; polyacetate derived anthraquinones + [?level]; outer epidermal walls of root elongation zone with cellulose fibrils oriented transverse to root axis; P more or less whorled, 3-merous [possible positiion]; embryo sac bipolar, 8 nucleate, antipodal cells persisting; endosperm triploid; ?germination.

[CHLORANTHALES [[MAGNOLIALES + LAURALES] [CANELLALES + PIPERALES]]]: sesquiterpenes +; seed endotestal.

[[MAGNOLIALES + LAURALES] [CANELLALES + PIPERALES]] / MAGNOLIIDS / MAGNOLIANAE Takhtajan: (neolignans +); vessels solitary and in radial multiples; (sieve tube plastids with polygonal protein crystals); lamina margins entire; A many, spiral [possible position here], extrorse; ovules with hypostase, nucellar cap +, raphal bundle branches at the chalaza; antipodal cells soon die.

[MAGNOLIALES + LAURALES]: palmitol the main wax; A whorled; pollen with lamellate endexine; carpel cross-zone initiated late; ovules 1(-2)/carpel, basal, erect, apotropous; fruitlets 1-seeded.

LAURALES Berchtold & Presl  Main Tree, Synapomorphies.

(Cork subepidermal); sieve tube plastids with polygonal protein crystalloids and starch; nodes 1:?; petiole bundle(s) arcuate; leaves opposite; inflorescence ± cymose; hypanthium +, P spiral; inner staminodia +; receptacle ± concave, stylulus long, (extragynoecial compitum +); megaspore mother cells several; fruits indehiscent, hypanthium persistent; mesotesta crushed, seed endotestal, endotesta tracheidal, tegmen crushed; embryo long; duplication of the PI gene. - 7 families, 91 genera, 2858 species.

Note: Possible apomorphies are now being added throughout the site; they are in bold. However, the actual level at which many of these features, particularly the more cryptic ones, should be assigned is unclear. This is because there is very considerable homoplasy, with variation within and between clades, for most characters. Furthermore, the basic information for all too many characters is very incomplete, often coming from taxa well embedded in the clade of interest and so making the position of any putative apomorphy uncertain. Then there is the not-so-trivial issue of how ancestral states are reconstructed...

Evolution. Divergence & Distribution. Magallón and Castillo (2009: relaxed and constrained penalized likelihood datings) suggest ages for the crown group of ca 171.4 and 119.3 m.y., while Magallón et al. (2013) suggested an age of around 117.5 m.y..

See Renner (2005a) for details of diversification within Laurales.

The young fruits of Protomonimia, in Turonian deposits from Japan that are ca 91 m.y. old, have several carpels borne in spirals on a concave axis; there is a stigmatic crest. The young seeds have a thick testa, the exotesta being palisade and with sinuous anticlinal cell walls (Nishida & Nishida 1988). If a member of Laurales, it would probably be assigned to stem Laurales if only because there are several ovules/carpel.

Soltis et al. (2005b) summarize information on possible synapomorphies for the clade (see also Staedler et al. 2009); von Balthazar et al. (2011) map the distributions of many characters in the order.

Genes & Genomes. Oginuma and Tobe (2006) suggest that the base chromosome number for Laurales is x = 11.

Chemistry, Morphology, etc. Isorhamnetin occurs in Lauraceae, Gomortegaceae and "Monimiaceae" (Crawford et al. 1986). The apex of the ovule in some Atherospermataceae, and perhaps also in Siparunaceae and Calycanthaceae, is exposed (Endress & Igersheim 1997). Little is known of obturator presence in the order, and of many other embryological details, although Endress (1972a) suggests there is considerable variation, some of which may link nicely with phylogeny.

See also Metcalfe (1987) for anatomy, Endress and Igersheim (1997) and Eklund (1999) for general information, Endress (2011a) for the distribution of an extragynoecilal compitum, and Kimoto and Tobe (2001) for embryology.

Phylogeny. Calycanthaceae are sister to other members of the clade, but there is little other well-supported structure in interfamily relationships. [Siparunaceae [Gomortegaceae + Atherospermataceae]] form a moderately-supported clade, relationships between the last two being supported strongly in D. Soltis et al. (2000, 2011), [Monimiaceae + Lauraceae + Hernandiaceae] another, sister-group relationships between the last two had no support (D. Soltis et al. 2000). However, in a morphological study [Hernandiaceae + Lauraceae] has strong support (Doyle & Endress 2000, see also Renner & Chanderbali 2000). However, the [Monimiaceae + Lauraceae + Hernandiaceae] clade is one of the few cases where there seems to be persistent disagreement between morphology and molecules (Renner & Chanderbali 2000). Here I follow morphology (see Renner 2005a for the most recent study, see also Renner et al. 1997 and Renner 1998, 1999).

Classification. The contents of Cronquist's (1981) Laurales and Takhtajan's (1997) Lauranae are largely the same as Laurales as they are circumscribed here.

Thanks. I am grateful to S. Renner for comments.

Includes Atherospermataceae, Calycanthaceae, Gomortegaceae, Hernandiaceae, Lauraceae, Monimiaceae, Siparunaceae.

Synonymy: Atherospermatales Martius, Calycanthales Link, Gyrocarpales Dumortier, Hernandiales Martius, Illigerales Martius, Monimiales Berchtold & Presl - Lauranae Takhtajan - Calycanthidae C. Y. Wu, Lauridae C. Y. Wu - Lauropsida Horaninov

CALYCANTHACEAE Lindley   Back to Laurales

Deciduous or evergreen shrubs to trees; tryptamine [calycanth(id)ine] alkaloids +; primary stem ± with vascular cylinder; cortical bundles +, inverted; vessel elements with simple perforation plates; sieve tube plastids also with peripheral protein fibres; pericyclic fibres 0; nodes 1:2 [see below]; petiole bundle arcuate, with wing bundles; hairs unicellular; buds with scales; lamina vernation flat to curved; flowers large [³3 cm across], (terminal); cortical receptacular vascular system; P many, spiral; A with prolonged connective, nectariferous staminodes ³10; (pollen trinucleate); stigma dry; ovules (2/carpel), micropyle exostomal, outer integument 6-15 cells across, inner integument 4-5 cells across, hypostase +; embryo sac long; fruits ± achenes; testa multiplicative, exotestal cells cuboid, slightly lignified; endosperm lacking paternal contribution, 0; n = 11.

5[list]/11 - two groups below. East Asia, North America, N.E. Australia (map: from Wu 1983; Endress 1983; Hong 1993; Fl. N. Am. III 1997; Qian & Ricklefs 2004). [Photo - Fruit © Robert Kowal, Flower.]

1. Idiospermoideae Thorne

Flavonols 0, but luteolin, etc. +; (vessel elements with scalariform perforation plates); stamens almost P like, thick, subsessile; G 1-2(-5), style 0, stigma stout, fleshy, extragynoecial compitum +; outer integument 12-15 cells thick, nucellar beak +; seed large [³3 cm across], cotyledons (3-)4, peltate.

1/1: Idiospermum australiense. Queensland, Australia.

Synonymy: Idiospermaceae S. T. Blake

2. Calycanthoideae Burnett

P 10³; A 5-18, filaments rather slender, (anthers valvate - Sinocalycanthus), pollen equatorially and vertically disulcate; G ³5, stigma filiform, compitum by style coherence; outer integument 5-6(-8) cells thick; cotyledons spirally twisted; (n = 12).

4/10. China, Korea, Taiwan, North America.

Synonymy: Butneriaceae Barnhart, Chimonanthaceae Perleb

• Calycanthaceae can be recognised by their opposite, entire, exstipulate leaves that smell aromatic. The cortical bundles can be seen with a lens when the stem is cut, and they may also be visible externally as four, raised lines along the stem. The terminal bud often aborts. The large flowers have a bract-covered hypanthium; the inner members of the perianth secrete nectar or bear food bodies. The achenial fruits are attached to the inside of the rather dry hypanthium. [Photo - Flowers]

Evolution. Divergence & Distribution. Crown group Calycanthaceae may have started to diverge in the Campanian, ca 110 m.y.a. (Zhou et al. 2006). Divergence within Calycanthaceae had begun by about 90 m.y.a. (Jerseyanthus: Crepet et al. 2004)

Fossils are interesting. Araipa florifera, from the Lower Cretaceous of Brasil, has flowers that externally are very like those of Calycanthaceae, but its leaves are lobed (Mohr & Ecklund 2003); unfortunately, nothing is known of the internal structure of the flower. The late Cretaceous Virginianthus calycanthoides (98-113 m.y. old) has been placed in Calycanthaceae. It has small flowers, anthers dehiscing by lateral hinges, and reticulate pollen with a single sulcus (Friis et al. 1994). Its anasulcate pollen is like that of Idiospermum, plesiomorphic for the order. Assuming the lateral hinges on the anthers of Virginianthus are equivalent to the rather differently oriented hinges found in most other taxa (c.f. also those of Sinocalycanthus - parallelism?), hinged anthers may be a synapomorphy for the order, and anthers with slits a synapomorphy for crown-group Calycanthaceae. However, the phylogenetic position of Virginianthus has been questioned, and whether it is in Calycanthaceae, sister to Calycanthaceae (e.g. Doyle & Endress 2010), sister to all other Laurales, or even to be included in Laurales at all is unclear (Eklund 1999; Crepet et al. 2005; Zhou et al. 2006; Doyle & Endress 2007; Doyle et al. 2008b), although the latter idea is least likely. The Australian Lovellea also has disulcate pollen, but phenetic analyses suggest that it may be sister to Laurales minus Calycanthaceae (see below: Dettmann et al. 2010). The rather younger (Turonian, ca 90 m.y. old) Jerseyanthus is more certainly Calycanthaceae, and it may even be sister to Calycanthus; it has the same distinctive disulcate pollen (Crepet et al. 2004, 2005). However, Jerseyanthus is remarkable in having flower parts in the sequence petal-like tepal (outside) - introrse staminode - extrorse stamen - abaxially curved "petal-like staminode" - pistillode (inside), an arrangement of parts quite unlike that of any other angiosperm, although Staedler et al. (2007) interpret the outer staminode series as being inner tepals.

For possible apomorphies of the two subfamilies in addition to those suggested above, see Staedler et al. (2009).

Genes & Genomes. Isozyme duplication in Calycanthus suggests that this clade shows ancient polyploidy (Soltis & Soltis 1990).

Chemistry, Morphology, etc. The two rings of vascular tissue in the stem are quite distinct from the seedling stage onwards. The leaf is innervated by paired traces from the inner vascular ring which very soon fuse and form the median petiole bundle, and then by two traces from the cortical bundles that form the lateral or wing bundles (Beck et al. 1982), however, I could not see these central paired traces in Chimonanthus (stem too old?). Odd teeth are sometimes found on the lamina of Calycanthus virginianus, at least on the plant in my back garden.

Calycanthus occidentalis has inverted recurrent vascular bundles in the hypanthium, perhaps evidence of receptacular epigyny (Dengler 1972). Staedler et al. (2007a) note that the numbers of floral parts, tepals, stamens, staminodes, etc., are more or less Fibonacci numbers (3, 5, 8, 13,....). The carpels in general are more or less plicate. The ovules of Calycanthus are close to tenuinucellate, but have a nucellar cap (Dahlgren 1927) and the micropyle is bistomal (Yamada et al. 2003). There is no triple fusion during fertilisation, and the endosperm develops autonomously. The seeds are poisonous and have characteristic alkaloids.

In morphology and anatomy, Idiospermum is similar to Calycanthaceae s. str., although the alkaloids and the distribution of xylem parenchyma differ in detail. For the morphology of Idiospermum, see Blake (1972), for chemistry, see Crawford et al. (1986).

For general information, see Nicely (1965) and Kubitzki (1993b), for the chloroplast genome, etc., see Goremykin et al. (2003b), for disulcate pollen of Calycanthus, see Albert et al. (2011), for floral development, see Rauh and Reznik (1951), for gynoecial development, see Staedler et al. (2007b).

Phylogeny. Li et al. (2004) clarify phylogenetic relationships in the family; Idiospermum is sister to the rest.

Classification. Although Idiospermum is a very distinctive genus and has sometimes been recognised as a separate family (e.g. Cronquist 1981), it is monotypic and shares many features with the rest of the family.

[[Siparunaceae [Gomortegaceae + Atherospermataceae]] [Monimiaceae [Hernandiaceae + Lauraceae]]]: evergreen trees; (plants Al accumulators); vessel elements with scalariform perforation plates; hippocrepiform sclereids in pericycle; mucilage cells + [this level; lamina with rather distant teeth, one vein entering opaque, persistent glandular cap; flowers rather small, inconspicuous; A whorled, stamens with paired nectaries/glands at base, anthers bisporangiate, monothecal, valvate, valves apically hinged; tapetum ?; pollen inaperturate, exine thin, ± spinulose, intine thick, outer part with radial channels; ovule median, on early-initiated cross-zone, vascular bundle not branching in chalaza; fruit fleshy, (splitting irregularly).

Evolution. Divergence & Distribution. Fossils estimates of the age of this clade are ca 91 m.y. (Crepet et al. 2004: note topology). Fossils of Lovellea wintonensis from the upper Albian of Queensland, Australia, have characters suggesting Laurales, although they do not suggest any particular family; morphological cladistic analyses place it somewhere around here (Dettmann et al. 2010). It has disulcate pollen, an inferior ovary, partly fused carpels with long styluli, the ovule has a hypostase, and the seed has two layers of cells, the inner being made up of transfer cells, each including a crystal; it lacks staminodes (Dettmann et al. 2010). Dettmann et al. (2010) compare Lovellea wintonensis most closely with Gomortega (Gomortegaceae) and Tambourissa (Monimiaceae), i.e. taxa on both branches of this clade.

Chemistry, Morphology, etc. Leitão et al. (1999) summarize alkaloid distribution in Monimiaceae in the old sense, which includes Atherospermataceae, Monimiaceae s. str., Siparunaceae and sometimes even Hernandiaceae.

Staedler and Endress (2009) discuss floral phyllotaxis; there is considerable variation, with whorled and spiral phyllotaxis occurring in all families that are not monotypic and phyllotaxis even varying within a species. There is also variation in exine structure in this part of the tree, the pollen of many taxa having an infratectum that is more or less intermediate between granular and columellar (Doyle 2009).

There is little information on tapetal development and most other embryological details and of seed anatomy; this is especially true of the first three families (Kimoto & Tobe 2001 for a summary; Bello et al. 2002a for Siparuna). See Doyle (2007) for leaf teeth and Hesse and Kubitzki (1983) for pollen ultrastructure. For information on Monimiaceae and the other families previously included in them, see Schodde (1970), Philipson (1993), Sampson (1993, 1997, 2007) and Foreman and Sampson (1987: pollen), Romanov et al. (2007: fruit anatomy) and Kimoto and Tobe (2008b: embryology).

[Siparunaceae [Gomortegaceae + Atherospermataceae]]: acicular crystals +; hypanthium closed by roof; pollen with columellar infratectum; embryo very small, endosperm copious.

SIPARUNACEAE Schodde   Back to Laurales

Also lianes; plants Al accumulators; indumentum often stellate; vessel elements also with simple perforation plates; no hippocrepiform sclereids in pericycle; primary stem?; nodes 1:1; petiole bundles flattened-annular, (medullar plate +); cuticle wax?; bud scales 0; lamina vernation curved-conduplicate, (margins entire); plants monoecious or dioecious, P 4-6(-7) or obscure, calyptrate; A (1-)2-many [e.g. 2 + 2 + 2], paired glands 0, anthers often with one flap, tapetum secretory; G 3-many, occluded by secretion as well, stylulus short; ovule unitegmic, integument 3-4(-5) cells across, hypostase +; megaspore mother cells several, embryo sacs several, starch-rich, elongating [Siparuna]; fruit splitting, (drupelet with a fleshy appendage - "stylar aril"); (seeds bilaterally flattened - Glossostigma), endotegmen with reticulate thickenings; n = 22.

2[list]/75: Siparuna (74). Tropical America (Siparuna), W. Africa (Glossocalyx) (map: S. Renner). [Photo - Flower] [Photo - Fruit]

• Siparunaceae may be recognised by their opposite, serrate, estipulate leaves with rather prominent brochidodromous venation; the wood lacks broad rays and the hairs are often stellate or fasciculate. The anthers lack basal glands.

Evolution. Pollination Biology & Seed Dispersal. Dioecy seems to have evolved several times from monoecy in Siparunaceae (Renner & Won 2001). Pollination is by genera of cecidomyid gall midges, which lay eggs mostly in male flowers; the larvae destroy the flower (Feil 1992).

The fruits of Siparuna may be a particulary valuable resource for frugivores (P. Jorgensen, pers. comm.). In most taxa the hypanthium splits irregularly when the fruits are ripe, the walls spreading widely and exposing the drupelets inside. The drupelets, and/or their fleshy appendages, differ strikingly in color from the inside of the fruit (see also Monimiaceae). This fleshy appendage is called an aril by Renner and Hausner (1997) and occurs only in dioecious taxa.

Chemistry, Morphology, etc. The ovule is interpreted as having lost its outer integument by Kimoto and Tobe (2003).

General information is taken from Philipson (1993), details of embryology may be found in Heilborn (1931) and Kimoto and Tobe (2003), floral morphology in Endress (1980c), and of pollen development, etc., in Bello et al. (2002a).

Phylogeny. For phylogenetic relationships in Siparunaceae, see Renner and Won (2001).

[Gomortegaceae + Atherospermataceae]: bud scales +; sieve tube plastids also with peripheral protein fibrils; outer A staminodial, inner A not staminodial; style short; endotesta tracheoidal.

Chemistry, Morphology, etc. Doweld (2001b) emphasized the similarities between Atherospermataceae and Gomortegaceae, especially the tracheoidal endotesta. Both have fruits (drupaceous, achenial) in which the seed coat would be expected to have lost its protective function.

GOMORTEGACEAE Reiche   Back to Laurales

Alkaloids?, Al accumulation ?; primary stem with separate bundles; nodes 1:2; secondary phloem with flaring rays; cuticle wax?; lamina entire; flower parts between spiral and whorled, hypanthium 0; P 5-7(-9); A 7-13, filaments rather slender; microsporogenesis modified simultaneous; G inferior, [2-3(-5)], style stout, branches erect, stigmatic, extragynoecial compitum?; ovule apical, hemianatropous [or straight?]; megaspore mother cell 1; fruit drupaceous; seed single (usu.), pachychalazal; n = 21.

1/1: Gomortega keule. C. Chile, rare (map: from Donoso Z. 1994). [Photo - Flower]

• Gomortegaceae are aromatic plants with opposite, estipulate, entire leaves. The flowers are small, with staminodes outside the stamens, the ovary is inferior and syncarpous, and the single-seeded fruit is drupaceous.

Chemistry, Morphology, etc. Vessel elements in young wood may have simple perforation plates (Metcalfe & Chalk 1987). Stern (1955) thought that nodal anatomy was unclear; here I follow Howard (in Metcalfe & Chalk 1987). The inflorescences, often described as being racemose, have a terminal flower. Although the body of the ovule is straight, its insertion on the funicle is oblique (c.f. Endress & Igersheim 1997). Ovule development and fruit and seed anatomy would repay investigation.

Some information is taken from Kubitzki (1993b: general), Doweld (2001: seed) and Heo et al. (2004: embryology).

ATHEROSPERMATACEAE R. Brown   Back to Laurales

Bisbenzylisoquinoline alkaloids +, Al accumulation 0; (hairs T-shaped); nodes 1:1; primary stem?; stomata anomocytic; lamina vernation involute [Laurelia] or conduplicate; inflorescence racemose; flowers ± polysymmetric; P = K + C; K, C; anthers bisporangiate, tapetum plasmodial; pollen polar di- or meridionally syncolpate, reticulate; G 4-many, occluded by secretion as well, (stylulus none); (megaspore mother cell 1); fruit achenial, plumose, hypanthium woody; embryo also medium; n = 22, 57.

6-7[list]/16. New Guinea to New Zealand and New Caledonia, Chile, scattered (map: Philipson 1986a; Andrew Ford, pers. comm. [Australia]). [Photo - Fruit]

• Atherospermataceae have opposite, coarsely serrate leaves in which the lateral veins join to form a looping vein inside the margin. The flowers are quite small, the hypanthium is dry, and the individual fruitlets are plumose and achenial.

Evolution. Divergence & Distribution. The family is known from forests on the Antarctic Peninsula of the late Cretaceous/early Tertiary, with wood recorded from the Upper Eocene of Germany; the oldest fossils are ca 88 m.y.. An age for the clade as a whole of ca 140 m.y. has been suggested (Renner et al. 2000).

Chemistry, Morphology, etc. The plants do not accumulate aluminium (Webb 1954). Atherosperma has two sepals completely enclosing the bud, and then eight petals. The vasculature of the anther glands is independent of that of the anthers (Canright 1952).

Some information is taken from Philipson (1993), Endress (1980c: flower), and Stanstrup et al. (2010: chemistry); for wood anatomy, see Poole and Gottwald (2001).

Phylogeny. Renner et al. (2000) suggest that a clade made up of Doryphora and Daphnandra, from the Queensland-New South Wales area of Australia, is sister to the rest of the family.

[Monimiaceae [Hernandiaceae + Lauraceae]]: aporphine alkaloids and variants +; (cork cambium outer cortical); crystals +, small; A whorled; pollen columellae foot layer and endexine 0; ovule apical, pendent, (micropyle bistomal).

Evolution. Divergence & Distribution. The distinctive Mauldinia (see below under Lauraceae) has been placed sister to this clade in a constrained morphological analysis by Doyle and Endress (2010) - this would date crown group diversification to something under 113 m.y.a. (actually, it has nothing much to do with this date). Diversification within Monimiaceae may have begun some 20 m.y. or more after it started within Hernandiaceae (c.f. Renner et al. 2010 [Monimiaceae] and Michlak et al. 2010 [Hernandiaceae]).

Chemistry, Morphology, etc. See Kimoto and Tobe (2008a) for a comprehensive summary of the variation in embryology and seed of the whole group.

MONIMIACEAE Jussieu   Back to Laurales

Also shrubs or lianes, climbing by scrambling; (plants Al accumulators); primary stem with cylinder or separate bundles; (vessel elements with simple perforation plates); wood with broad rays; nodes 1:1-7; sieve tubes with rosette-like non-dispersive protein bodies; cuticle wax?; (stomata anomocytic); lamina vernation conduplicate, (margins entire); plants monoecious or dioecious, (flowers perfect - Hortonia); flowers medium-sized, (hypanthium closed by roof); P 3-many, (much reduced), sepaloid, petal-like or calyptrate; A 3-many, anthers tetrasporangiate, dehiscing longitudinally, (annular), ± sessile or filaments rather slender, connective produced; paired nectaries 0, tapetum secretory [Peumus]; (pollen grains with encircling aperture); G (1-few)-many, occluded by secretion as well, stylulus short-0, stigma broad, dry, (extragynoecial compitum +); outer integument 2-4 cells across, inner integument 2-3 cells across, hypostase +, funicle stout, obturator + (0); hypanthium fleshy or not, fruit drupelets, (with fleshy appendages); mesotesta usu. tracheidal, (endotesta not tracheidal); embryo short to quite long.

22[list]/200. Tropical-Southern Hemisphere, but esp. Australasia.

1. [Peumus [Palmeria + Monimia]]

Lianes to trees; septate fibres 0; sieve tube plastids with starch (not Peumus); hairs often stellate; (bud scales +); plants dioecious; (anthers bisporangiate, dehiscing transversely - Monimia), staminodes +, (paired nectaries + - Peumus); endocarp massive; fruit splitting irregulary at maturity, or circumscissile; n = 39, ca 46.

3/19: Palmeria (15). Scattered: Chile, the Mascarenes, east Australia, New Guinea (Map: in part from Fl. Australiense 2. 2007).

[Hortonia + The Rest]: secondary phloem with flaring rays; septate fibres +; endocarp thin.

2. Hortonia

Shrubs; hairs stellate; flowers perfect; staminodes +; paired nectaries +; pollen with hollow, spiral sexinous strands, intine with tangential channels; fruit a drupe; n = 19.

1/3. Sri Lanka. (Map above: green)

Synonymy: Hortoniaceae A. C. Smith

3. The Rest

Lianes, shrubs or trees; (sieve tube plastids with starch - Tambourissa); plants monoecious; (extragynoecial compitum +); (paired nectaries + - Mollinedia); (cotyledons 4 - Kibaropsis); n = 19 [several], 22, 36, 39, 40-43.

18/180: Mollinedia (90 [?20 - S. Renner, pers. comm.]), Tambourissa (45), Kibara (45). Tropical-Southern Hemisphere, esp. Australasia.; fossil wood from the Campanian in Antarctica, etc. (map: from Renner et al. 2010, fossil localities in green; Jordaan & Lötter 2012, Xymalos).[Photo: Fruit, Flower, Fruit, Levieria fruit, Wilkiea fruit.]

• Monimiaceae are recognisable by their opposite, rather distantly serrate leaves which have prominent venation on the lower surface with the veins looping and joining near the margin, and their twigs, which often have broad rays and are often flattened below the somewhat swollen nodes; some taxa have "laticiferous threads" (Keller 1996). In fruit, the well-developed fleshy hypanthium and/or receptacle is conspicuous; this may enclose the drupelets and it then splits irregularly.

Evolution. Divergence & Distribution. Wikström et al. (2001) date diversification within the clade to (96-)78(-70) m.y.a.; Renner et al. (2010) suggest that crown Monimiaceae are (93-)90(-87) m.y. old (there are ca 85 million year old fossil woods), with diversification between Hortonia and the rest occuring (85-)71(-57) m.y.a. (95% HPD values); dates in Michalak et al. are 80-40 m.y., depending on the clock. Within the rest, divergence of Xymalos occured (33-)30(-28) m.y.a. (fossils) or (58-)44(-31) m.y.a. (Renner et al. 2010). The separation of Monimia from its sister genus, the East Malesian Palmeria dates to (48-)32(-16) m.y.; the former is endemic to the Mascarenes, which are a mere 15-8 m.y. old (Renner et al. 2010), so Monimia must have dispersed on to the islands from elsewhere (?Malesia). In general, there is little evidence of Gondwananan vicariance in the family (Renner et al. 2010).

Pollination Biology & Seed Dispersal. A hyperstigma or extragynoecial compitum may be present, the pollen germinating on a mucilaginous secretion at the entrance to the hypanthium (Endress 1980c; Friis & Endress 1990). A variety of small insects pollinate the flowers the parts of which may be more or less exposed or enclosed in a fig-like structure. In the latter case, thrips (Thysanoptera) lay their eggs in young inflorescences, adults covered in pollen emerging when the flowers are mature, although the evidence for this is little better than anecdotal (c.f. Siparunaceae: Gottsberger 1977; Philipson 1986a).

In genera like Palmeria, Tambourissa, etc., the drupelets are surrounded by a fleshy, accrescent hypanthium. This splits, exposing the fruits, and the colour of the inside sometimes forms a striking contrast with that of the drupelets.

Plant-Animal relationships. Papilio dardanus caterpillars have been found on Xymalos (Jordaan & Lötter 2012).

Chemistry, Morphology, etc. Decaryodendron has flowers with up to 1000 carpels, and flowers of Tambourissa have up to 2000 carpels; Mollinedia has carpels that are initially unsealed, but are later occluded by secretion; it also has a whorled perianth. Since the ovules are initiated on the cross-zone, in their apical position they have effectively been inverted 180^o.

For the Malagasy taxa, see Lorence (1985), for floral development, see Endress (1980b: but Hortonia neither notably intermediate nor archaic, 1980c), von Balthazar et al. 2011, for wood anatomy, see Poole and Gottwald (2001), and for fruit anatomy, see Romanov et al. (2007).

Phylogeny. A [Peumus [Palmeria + Monimia]] clade [= Monimieae] is sister to the rest of the family (Renner 2002 and references), Hortonia is isolated, but then relationships are unclear, although the monotypic Xymalos, the only mainland African member of Monimiacaee, is likely to be sister to the remainder. Fruit anatomy correlates quite well with phylogeny, e.g., Monimieae have a massively thick endocarp, alone in the family (Romanov et al. 2007).

Previous Relationships. Only three of the subfamilies (Monimioideae, Hortonioideae and Mollinedioideae) of Monimiaceae as circumscribed by Money et al. (1950), Cronquist (1981), and Takhtajan (1997) are included here; for the rest of the family, see Siparunaceae and Atherospermataceae.

[Hernandiaceae + Lauraceae]: primary stem ± with vascular cylinder; vessel elements with simple perforation plates; hippocrepiform cells in pericycle?; leaves spiral, lamina margins entire, (lobed); P whorled; (filaments slender); tapetum amoeboid; microspore mother cells in single layer; exine thin, spines set in a reduced granular layer, intine very thick, outer layer with a radially oriented microfibrillar structure; G 1, stylar canal 0, stigma dry; ovule pachychalazal, outer integument ³4 cells across, (micropyle not covered), hypostase 0; embryo sac more or less linear; testa thick, multiplicative; endosperm 0; germination epigeal.

Evolution. Divergence & Distribution. The fossil Mauldinia may best be placed here, rather than within Lauraceae (Doyle & Endress 2007). Bandulskaia, from the Early Eocene of Tasmania and identified as Lauraceae based on several distinctive epidermal features, has huge leaf teeth 2000+ µm long that lack the glandular cap of teeth of other Laurales; if the fossil is correctly identified, independent origin of these teeth is likely (Carpenter et al. 2007). Cohongarootonia (it has a hollow style) and perhaps Powhatania, both from Early-Middle Albian sediments 125-118 m.y. old in Virginia probably belong in this general area (von Balthazar et al. 2011).

For additional possible synapomorphies, see Doyle and Endress (2000). A scenario for ovary evolution is that it became inferior in the common ancester of Hernandiaceae and Lauraceae, being lost (?more than once) in the latter family - both require two steps (two gains, versus gain and subsequent loss). Protrusion of the embryo sac from the nucellus may ultimately go here, too.

Pollination Biology. Rohwer (2009) compares the heterodichogamous flowers of Lauraceae with those of Hernandiaceae (for Hernandia, see Endress & Lorence 2004) and suggests that heterodichogamy may be common to the two. he interprets the floral morphology of Hernandiaceae in this context; heterodichogamy may be another synapomorphy at this level.

Chemistry, Morphology, etc. For the distinctive pollen of these two families, see Kubitzki (1981).

HERNANDIACEAE Blume   Back to Laurales

Trees or lianes; hippocrepiform sclereids in pericycle?; nodes 1:3-9; petiole bundles horizontally [Valvanthera] or vertically elliptic; (stomata anomocytic); branching from previous flush; lamina venation ± palmate; breeding system very variable; flowers (3-)4-5-merous; P 3-10; A 3-5(-7); (nectaries outside A, 0, or much reduced); ovary inferior, usu. facing abaxially, stigma peltate; ovule micropyle variable, endostome lobed, outer integument 9-23 cells across, inner integument 3-8 cells across; fruit dry, (a samara).

5[list]/55 - two subfamilies below. Pantropical.

1. Hernandioideae

(Climbing by twining petioles); Al accumulation?; glandular hairs in leaf epidermis; plant heterodichogamous; inflorescence thyrsoid; anther valves laterally hinged; tapetal cells radially elongated; pollen grains 90-160 µm across; parietal tissue 6-8 cells across, nucellar beak +, suprachalazal nucellus massive; bracteoles accrescent in fruit [not Illigera]; (seeds ruminate - usu. Hernandia), testa vascularized, spongy, tanniniferous, walls unthickened, mesotesta massive, 7-17 cells across; n = 18, 20.

3/44. Tropical, esp. Madagascar and Indo-Malesia (map: from Kubitzki 1969; van Balgooy 1975; Trop. Afr. Fl. Pl. Ecol. Distr. 1. 2003). [Photo - Hernandia Flower, Fruit, Illigera Flower, Fruit.]

Synonymy: Illigeraceae Blume

2. Gyrocarpoideae Pax

Leaves with cystoliths, strong higher-order vein areolation; inflorescence dichasial, ebracteate; flowers very small; P uniseriate; ?microspore mother cells?; pollen grains 19-45 µm across; ovule with nucellar cap; apical part of embryo sac protruding from nucellus; cotyledons contortuplicate [much folded!]; n = 15.

2/10. Pantropical, esp. America (map: from Kubitzki 1969; van Balgooy 1975; Trop. Afr. Fl. Pl. Ecol. Distr. 1. 2003).

Synonymy: Gyrocarpaceae Dumortier

• Given the variation in life form and vegetative and fruit morphology in Hernandiaceae, this is not an easy family to recognise. Illigera (Hernandioideae) is a climber with palmately compound leaves and sensitive petioles that can even be mistaken for the monocot Dioscorea, Sparattanthelium (Gyrocarpoideae) is a climber with recurved stem hooks, while Hernandia itself is a tree.

Evolution. Divergence & Distribution. Stem Hernandiaceae are ca (102-)97(-92) m.y. old (Wikström et al. 2001). However, Michlak et al. (2010) suggest that crown-group diversification began (130-)112-108(-89) m.y.a., and there has been widespread dispersal subsequently.

Chemistry, Morphology, etc. Some 128 alkaloids assignable to 17 different structural types have been found in the family; about half of them are aporphine alkaloids (Conserva et al. 2005; see also J.-J. Chen et al. 2011). They show no obvious correlation with phylogeny.

For floral morphology in Hernandia, see Endress and Lorence (2004); see Heo and Tobe (1995) and Kimoto and Tobe (2008) for embryology, etc., and a nice summary in the latter. Some information is also taken from Kubitzki (1969, 1993b).

LAURACEAE Jussieu   Back to Laurales

Flavones, 5-O-methyl flavonols, polyketides [acetogenins], (tryptamine alkaloids) +, (plants Al-accumulators); vessel elements with scalariform perforation plates; wood often fluorescing; (secondary phloem stratified); nodes 1:2 (1:3); also crystals and crystal sand +; (stomata anomocytic); bud scales + (0); branching from current flush; leaves (opposite), lamina often glaucous below, vernation conduplicate or supervolute, higher-order vein areolation stong; plants heterodichogamous (polygamous to dioecious); inflorescence umbellate to thyrsoid; hypanthium often short, T 3 + 3 (2 + 2; K + C); A 3 [introrse] + 3 [often introrse] + 3 [extrorse; with glands], sporangia widely separated on broad connective; (microsporogenesis simultaneous); (pollen monosulcate); (stylulus 0), stigma also capitate; outer integument 3-5(-11) cells across, inner integument 2-4 cells across; megaspore mother cells usu. 1; fruit a drupelet [endocarp palisade], pedicels (and tepals) often thickened and colored; (seed ruminate), testa vascularized or not, often multiplicative, (exotestal cells cubic), endotestal cells longitudinally or transversely elongated; endosperm nuclear; n = (11-)12, chromosomes 1-5 µm long.

1. Hypodaphnis

Anthers tetrasporangiate; tapetum?; staminodes 0; G inferior.

1/1: Hypodaphnis zenkeri. Tropical West Africa.

[[Beilschmiedia, Cryptocarya, Endiandra, etc.] [Cassytha [[Caryodaphnopsis + Neocinnamomum] + The Rest]]]: subsidiary cells of paracytic stomata envelop the guard cell both above and below, the guard cells having outer and inner cuticular ledges; staminodes +, (4-several whorls of stamens; when dioecious, 3 whorls of staminodes in male plants, the third whorl of stamens=staminodes in female plants); glandular tapetum +; ovary superior to inferior; embryo sac protruding from nucellus: fruit type?

2. Beilschmiedia, Cryptocarya, Endiandra, etc.

Stamens in two whorls (three whorls, many); (G inferior); fruit a berry; (n = 15 - Eusideroxylon, Endiandra).

6/710: Cryptocarya (350), Beilschmiedia (250), Endiandra (80). Pantropical, some subtropical, to New Zealand.

[Cassytha [[Caryodaphnopsis + Neocinnamomum] + The Rest]]: ?

3. Cassytha L.

Parasitic herb; micropyle bistomal, nucellar cap 0, pachychalaza 0; endosperm cellular; chromosomes to 7 µm long..

1/16. Tropics, warm temperate regions in Australia - see The Parasitic Plant Collection. [Photo - Parasite.]

Synonymy: Cassythaceae Lindley, nom. cons.

4. [Caryodaphnopsis + Neocinnamomum] + The Rest]: ?

[Caryodaphnopsis + Neocinnamomum]

Anthers tetrasporangiate.

2/21. Central and South America, South East Asia to the Philippines and Borneo.

5. The Rest.

(Plant deciduous); (cork pericyclic - Cinnamomum); (flowers 2-merous - Potameia); (paired nectaries/glands 0 - Mezilaurus clade); tapetum amoeboid; embryo sac not protruding.

Ca 40/1730: Ocotea (350), Litsea (?400), Persea (200), Cinnamomum (350: cinnamon), Lindera (100). Pantropical (temperate). [Photos - Flower, Fruit.]

Synonymy: Perseaceae Horaninow

• The family may be recognised by its aromatic smell, nearly always entire, spiral or opposite (very rarely two-ranked) quite long-petiolate leaves. The leaf blades are often quite thick (they are coriaceous when dry) and have a glaucous undersurface and rather steeply ascending secondary veins. The bark oxidises (turns red-brown) on exposure. The twigs are more or less ridged, the ridges being decurrent from the bases of the petioles, and branching is often on the current flush - even in temperate taxa there is often a mixture of proleptic and sylleptic branching. The flowers are rather small, trimerous, and have valvate anthers; the fruit has a single, large seed that lacks endosperm and the pedicel - and sometimes also tepals and hypanthium - is often swollen and conspicuous. Some Lauraceae have a growth pattern similar to that of Myristicaceae, with whorled branches and periodic growth, but the leaves on the branches of Myristicaceae the leaves are nearly always distichous.

Evolution. Divergence & Distribution. Chanderbali et al. (2001) suggest a stem age of 174 ± 32 m.y. for the family, but its diversification may be as recent as (93-)61(-26) m.y.a. (Michalak et al. 2010).

Lauraceae are prominent in Mid to Late Cretaceous floras. Labandeira et al. (2002b) assigned many fossil leaves from the earliest Tertiary of North America to extant genera of Lauraceae, while wood very similar to that of sassafras is known the Late Cretaceous of Antarctica ca 83 m.y.a. (Poole et al. 2000). Early Cenomanian Mauldinia, ca 100 m.y. old (Drinnan et al. 1990; Viehofen et al. 2008), has remarkable inflorescences in which the lateral units are flattened and bilobed, bearing sessile flowers on their adaxial surfaces. The flowers are very like those of extant members of the family (see also Crepet et al. 2004; Friis et al. 2006b for references), but the distichous bracts/prophylls of the inflorescence units is a distinctly unusual feature here. A flower provisionally assigned to Lauraceae, although with a unusual combination of floral characters - there are only two whorls of stamens and no nectaries/glands - has been described from deposits in Virginia some 112-105 m.y. old (von Balthazar et al. 2007). The Upper Cretaceous Marmarthia has leaf blades with palmate venation; the margins are lobed or perhaps toothed (Peppe et al. 2007).

A better understanding of biogeographic relationships will depend on a more complete phylogeny. The Macaronesian Persea indica is part of a New World clade - and sister (but with rather poor support) to this clade is another Macaronesian member of the family, Apollonias barbujana (Rohwer et al. 2009). Diversification in the speciose New World Ocotea is likely to have been rather recent (Renner 2005a). It is unclear what to make of wood identified as the north temperate Sassafras that turned up at 60^o S on Seymour Island in the Antarctic in rocks ca 83 m.y. old (Poole et al. 2000).

Ecology & Physiology. The family is prominent in the lowland tropical rainforests of South East Asia-Malesia and America in particular, much less so in Africa, and in tropical montane forests in South America it may be the most speciose family (Gentry 1988). Eusideroxlum zwageri dominates (or used to - it has been heavily logged) several thousand square kilometres of West Malesian forests (Hart et al. 1989), while Litsea is one of the five most diverse genera in West Malesian t.l.r.f. (Davies et al. 2005).

Pollination Biology & Seed Dispersal. The basic mode of flowering in the family may be heterodichogamy or dianthesis. Plants are of two types, and one plant will be in the staminate phase while the other is in the carpellate phase, and vice versa. The staminodes produce nectar when the plant/flower is in the carpellate phase and the staminal glands of the third staminal whorl produce nectar when the plant/flower is in the staminate phase (Rohwer 2009, see also above).

Dispersal of the fruits is by animals, specialized frugivores for the most part. The seeds are relatively large, and the pericarp, although thin, is nutritious (Snow 1981).

Chemistry, Morphology, etc. Lindera, at least, has distinctive C₁₀, C₁₂ and C₁₄ monounsaturated fatty acids in its seeds (Badami & Patil 1981). Vestured pits are apparently absent; rays alone may be storied (Metcalfe 1987: P. van Rijckevorsel [pers. comm.] clarified reports of vestured pits and wood storying in the family). Distinctive paracytic stomata in which the subsidiary cells almost envelop the very small guard cells, the latter having outer and inner cuticular ledges, may be an apomorphy for all Lauraceae except Hyphodaphnis (Carpenter et al. 2007), however, Nishida and van der Werff (2007) found more conventional stomata in at least some Lauraceae other than Mezilaurus (for stomata, see also Hill 1986). Indeed, from a surface view it may seem as if the stomata are anomocytic, the guard cells being totally obscured.

It has been suggested, largely on the basis of gene expression, that the perianth in some Lauraceae - Persea, at least - may represent modified stamens (Chanderbali et al. 2004, 2006). Both the tepals and the stamens of Persea have three traces (Reece 1939: the ovule is reported to be anatropous!). However, other reports suggest that the stamens have single traces, even if both whorls of tepals have three traces (Laurus) or one trace in the inner whorl alone (Umbellularia: Kasapligil 1951). More work is needed here. Multistaminate Lauraceae attain this condition by the increase in number of the stamen whorls. Dahlgrenodendron has pollen grains with exine, columellae, etc. The orientation of the single carpel varies (Ronse de Craene et al. 2010 and literature). Kimoto et al. (2006) summarize embryological findings in Lauraceae. Variation in the anatomy of the pericarp, development of the cupule in fruit, etc., is summarized by Little et al. (2009). The testa is not always multiplicative. Kasapligil (1951) described a tracheidal endotegmen at the radicular end of the seed. Both isozyme duplication and stomatal size increase over time suggest ancient polyploidy in this clade (Soltis & Soltis 1990; Masterson 1994). Is the base chromosome number 6?

Kimoto et al. (2006) note that a minor change on the tree that they used would mean that a glandular anther tapetum and possibly also protruding embryo sac arose on a single clade and did not reverse; they thought that characters like a glandular tapetum and an embryo sac protruding from the nucellus arose in parallel. However, in the topology suggested by Rohwer and Rudolph (2005, not cited by Kimoto et al. 2006) these characters appear in all (glandular tapetum) or most (protruding embryo sacs) members that have been examined on three successive branches of the tree, but are not, or only very rarely, found in the Mezilaurus group and other core Lauraceae ("The Rest" above). Thus there may have been reversal/loss of these characters in other Lauraceae; protruding embryo sacs are also found in Hernandiaceae-Gyrocarpoideae. I have optimised these and some other characters (see von Balthazar et al. 2007) in the context of a the phylogeny of Lauraceae suggested by Rohwer and Rudolph (2005: see below). However, where many of these characters will end up on the tree is very uncertain; the topology is uncertain and our basic understanding of the morphological variation is poor.

General information is taken from Rohwer (1993a), some embryological details from Heo et al. (1998) and Endress and Sampson (1983), wood anatomy from Richter (1981) and van Rijckevorsel (2002), fruit anatomy from Heo (199-), stomata from van der Merwe and van Wyk (1994), cuticle from Christophel et al. (1996) and Nishida and van der Werff (2011), cytology from Oginuma et al. (1998), chromosome size from de Moraes et al. (2007), and androecial development from Buzgo et al. (2007).

Phylogeny. Hypodaphnis, with an inferior ovary, is sister to the rest of the family, then Cassytha (but a long branch), then [Beilschmeidia + Cryptocarya + Endiandra], then Caryodaphnopsis, then [Chlorocardium + Mezilaurus + Williamodendron] (Rohwer 2000: matK); for more details, see Chanderbali et al. (2001). There are a number of taxa with long branches, and complex analyses by Rohwer and Rudolph (2005) strongly suggest a slight modification of these relationships: [Hypodaphnis [[the Cryptocarya group] [Cassytha [[Caryodaphnopsis + Neocinnamomum] [[the Mezilaurus group] [core Lauraceae]]]]]] - most of these clades have about 100% posterior probabilities. If this topology is confirmed, it will have considerable implications for character evolution (see above).

Litsea is polyphyletic, although section Litsea is monophyletic, and Lindera is also polyphyletic (Fijridiyanto & Murakami 2009). The recognition of Neolitsea appears to make Actinodaphne paraphyletic (Li et al. 2007, esp. 2008). For relationships in the Persea area, see Rohwer et al. (2009); Phoebe and Persea are para/polyphyletic.

Classification. The classical genera are very difficult to recognise without flowers and are rather unsatisfactory even with them. They are often based on single character differences in the androecium, such as sporangium number and direction of sporangium opening. However, both extrorse and introrse anthers can occur in the same flower, although the extrorse condition seems to be developmentally derived (Buzgo et al. 2007), thecae may be 2 or 4, their arrangement on the connective varies, etc. (e.g. Kopp 1966; Rohwer et al. 1991; Rohwer 1993, 1994a; van der Werff & Richter 1997); substantial changes in generic limits are to be expected.