EXTANT SEED PLANTS
Plant woody, evergreen; nicotinic acid metabolised to trigonelline; primary cell walls rich in xyloglucans and/or glucomannans, 25-30% pectin [Type I walls]; lignins rich in guaiacyl units; true roots present, xylem exarch, branching endogenous; arbuscular mycorrhizae +; shoot apical meristem complex; stem with ectophloic eustele, endodermis 0, xylem endarch, branching exogenous; vascular tissue in t.s. discontinuous by interfascicular regions; vascular cambium + [xylem ("wood") differentiating internally, phloem externally]; wood homoxylous, tracheids +; tracheid/tracheid pits circular, bordered; sieve tube/cell plastids with starch grains; phloem fibers +; stem cork cambium superficial, root cork cambium deep seated; nodes ?; stomata ?; leaf vascular bundles collateral; leaves spiral, simple, axillary buds?, prophylls [including bracteoles] two, lateral, veins -5(-8) mm/mm2; plant heterosporous, sporangia eusporangiate, on sporophylls, sporophylls aggregated in indeterminate cones/strobili; true pollen [microspores] +, grains mono[ana]sulcate, exine and intine homogeneous, ovules unitegmic, crassinucellate, 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, with cell walls, with many flagellae; female gametophyte endosporic, initially syncytial, walls then surrounding individual nuclei; seeds "large", first cell wall of zygote transverse, embryo straight, endoscopic [suspensor +], short-minute, with morphological dormancy, white, cotyledons 2; plastid transmission maternal; two copies of LEAFY gene, PHY gene duplication, mitochondrial nad1 intron 2 and coxIIi3 intron present.
MAGNOLIOPHYTA
Plant woody, evergreen; lignans, O-methyl flavonols, dihydroflavonols, triterpenoid oleanane, non-hydrolysable tannins, quercetin and/or kaempferol +, apigenin and/or luteolin scattered, cyanogenesis via tyrosine pathway [ANITA grade?], lignins derived from both coniferyl and sinapyl alcohols, containing syringaldehyde [in positive Maüle reaction, syringyl:guaiacyl ratio less 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; stem with 2-layered tunica-corpus construction; wood fibers and wood parenchyma +; reaction wood ?, with gelatinous fibres; starch grains simple; primary cell wall mostly with pectic polysaccharides; tracheids +; sieve tubes eunucleate, with sieve plate, companion cells from same mother cell that gave rise to the tube, the sieve tube with P-proteins; nodes unilacunar; stomata with ends of guard cells level with aperture, paracytic; leaves with petiole and lamina [the latter formed from the primordial leaf apex], development of venation acropetal, 2ndary veins pinnate, fine venation reticulate, vein endings free; flowers perfect, polysymmetric, parts spiral [esp. the A], free, development in general centripetal, numbers unstable, P not differentiated, outer members not enclosing the rest of the bud, smaller than inner members, A many, with a single trace, introrse, filaments stout, anther ± embedded in the filament, tetrasporangiate, dithecal, with at least outer secondary parietal cells dividing, each theca dehiscing longitudinally by action of hypodermal endothecium, endothecial cells elongated at right angles to long axis of anther, tapetum glandular, binucleate, microspore mother cells in a block, microsporogenesis successive, walls developing by centripetal furrowing, pollen subspherical, binucleate at dispersal, trinucleate eventually, tectum continuous or microperforate, exine columellar, endexine thin, compact, lamellate only in the apertural regions, pollen germinating in less than 3 hours, tube elongated, growing at 80-600 µm/hour, with callose plugs and callose-based walls, penetrating between cells, siphonogamy, penetration of ovules within ca 18 hours, distance to first ovule 1.1.-2.1 mm, nectary 0, G free, several, ascidiate, with postgenital occlusion by secretion, few [?1] ovules/carpel, ovules marginal, anatropous, bitegmic, [outer integument often largely subdermal in origin, inner integument dermal], micropyle endostomal, integuments 2-3 cells thick, megasporocyte single, megaspore lacking sporopollenin and cuticle, chalazal, female gametophyte ?type, stylulus short, hollow, stigma ± decurrent, wet [secretory]; P deciduous in fruit; seed exotestal; double fertilisation +, endosperm ?diploid, cellular [first division oblique, micropylar end initially with a single large cell, chalazal end more actively dividing], copious, oily and/or proteinaceous, embryo cellular ab initio; germination hypogeal, seedlings/young plants sympodial; Arabidopsis-type telomeres [(TTTAGGG)n]; whole genome duplication, 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 PHYA/PHYC gene pairs.
Possible apomorphies are in bold. Note that the actual level to which many of these features, particularly the more cryptic ones, should be assigned is unclear, because some taxa basal to the [magnoliid + monocot + eudicot] group have been surprisingly little studied. Furthermore, details of relationships among gymnosperms will affect the level at which some of these characters are pegged.
NYMPHAEALES [AUSTROBAILEYALES [[CHLORANTHALES + MAGNOLIIDS] [MONOCOTS [CERATOPHYLLALES + EUDICOTS]]]]: vessels +, elements with scalariform perforation plates; nucleus of egg cell sister to one of the polar nuclei; ?genome duplication; "DEAER" motif in AP3 and PI genes lost, gaps in these genes.
AUSTROBAILEYALES [[CHLORANTHALES + MAGNOLIIDS] [MONOCOTS [CERATOPHYLLALES + EUDICOTS]]]: ethereal oils in spherical idioblasts [lamina and P ± pellucid-punctate]; tension wood 0; tectum reticulate-perforate, nucellar cap + [character lost where in eudicots?]; 12BP [4 amino acids] deletion in P1 gene.
[CHLORANTHALES + MAGNOLIIDS] [MONOCOTS [CERATOPHYLLALES + EUDICOTS]] : benzylisoquinoline alkaloids +; P more or less whorled, 3-merous [possible position], carpels plicate; embryo sac bipolar, 8 nucleate, antipodal cells persisting; endosperm triploid.
to add where?: A whorled, carpel fusion by congenital occlusion
Relationships between the lineages immediately above the basal pectinations in the main tree, the ANITA grade (Amborellales, Nymphaeales and Austrobaileyales here), remain somewhat a matter of conjecture, although recent work is suggesting resolutions. The positions of Ceratophyllales and Chloranthaceae have been particularly labile, the former having been placed e.g. as sister to the eudicot lineage, or sister to all flowering plants. Indeed, Graham et al. (2005) found that the inclusion of these two in analyses could destabilise relationships among these early branching clades, e.g. the position of the monocots became labile. There has been weak support for an (eu)magnoliid clade being sister to the eudicots (e.g. D. Soltis et al. 2000; P. Soltis et al. 2000; Wu et al. 2007; Qiu & Estabrook 2008 [compatability analysis]), in the former Chloranthales, monocots, and Piperales were successively sister to the remaining taxa, Magnoliales, Canellales and Laurales also belonging, but these relationships also had little support. Hilu et al. (2003: a matK analysis alone), suggested that Ceratophyllaceae are sister to eudicots (see also D. Soltis et al. 2000; Borsch et al. 2005: 62% jacknife, 96% posterior probabilities, the study focussed on three rapidly evolving genes; Müller et al. 2006: 96% posterior probability; some analyses in Saarela et al. 2007; Qiu & Estabrook 2008). However, Zanis et al. (2002) analysed 11 genes from all genomes and found some support for the magnoliids (strong support for this clade) as being sister to eudicots, with Chloranthaceae, and [monocots + Ceratophyllaceae] occuring as successively more basal branches; below these were the ANITA grade (see also Graham & Olmstead 2000; Borsch et al. 2003). Support for some of these nodes depended on the method of analysis (see also Borsch et al. 2000; Graham & Olmstead 2000; Hilu et al. 2001; Whitlock et al. 2001; Zanis et al. 2002) or the particular gene studied (see Duvall & Bricker 2002 - nuclear 18s; Hilu et al. 2003 - matK; Duvall et al. 2006 - nuclear 18S in particular causes problems). Davis et al. (2004) found the magnoliids to be sister to monocots, with Chloranthaceae and Ceratophyllaceae successively sister to a clade including the few eudicots in the analysis, but support for none of these positions was exactly overwhelming (the best supported topology in Duvall et al. 2006 is somewhat similar). There was fairly good support for a grouping [monocots + Ceratophyllaceae] in a compartmentalised 6-gene analysis (Zanis et al. 2003; see also Qiu et al. 1999; some analyses in Saarela et al. 2007). Müller et al. (2006) found very poorly supported relationships between Chloranthaceae and monocots, which together linked with the magnoliids. In work by Whitlock et al. (2002) largely similar groupings were recognised, but support remains only moderate; the exact position of Chloranthaceae remained unclear. Some analyses suggested the possibility of a sister taxon relationship between Chloranthaceae and eudicots (Borsch et al. 2003), while Hilu et al. (2003) in a matK analysis, suggest that they are sister to monocots. Although the support is weak in parsimony analyses, there are 100% posterior probabilities in Bayesian analyses, furthermore, in the latter case only, [Chloranthacaeae + monocots] are sister to magnoliids, although the probabilities here are low. Qiu et al. (2005; see also Löhne & Borsch 2005) found initial rather strong bootstrap support for an association between monocots and Ceratophyllaceae in a 9-gene analysis being vitiated by the failure to obtain much support in any of the subanalyses and by details of the topology obtained in the 9-gene analysis itself (e.g. Acorus sister to the Alismatales that were included) that are rather improbable. Other studies with more restricted sampling also show no clear pattern (e.g. Jansen et al. 2006a). And on it goes! - relationships are unclear in Qiu et al. (2006b). Doyle and Endress (2000) presented combined morphological and molecular data that suggested Piperales might be sister to monocots, Parkinson et al. (1999) molecular evidence that they were sister to eudicots, but in both cases the support was weak, and neither position is likely; they are now firmly placed in the magnoliids. Interestingly, Piper has the "monocot" pattern of PHY genes (A, B, C genes only), while Ceratophyllum has PHYE (Mathews et al. 1995).
A polychotomy involving all these taxa is evident in P. Soltis et al. (1999: support low), while Soltis et al. (2005b) very reasonably summarise their discussion on relationhips in this area by showing a pentachotomy. It has been suggested that the discovery of structural changes in the genome might clarify relationships in this area (Löhne & Borsch 2005; Qiu et al. 2005). Indeed, some resolution may be on the way. Graham et al. (2005) recently found a rather weakly supported (73% bootstrap) [monocot + eudicot] grouping, but this was weaker when Chloranthaceae and Ceratophyllaceae were included. However, evolution of some floral developmental genes, e.g. in the C and D lineages, are also consistent with such a relationship (Kramer et al. 2004), as are the positional relationships between members of the androecium and the perianth (the stamens are individually opposite perianth members, although note that this relationship may be found in some magnoliids, e.g. Lauraceae), and perhaps some other characters (trimery of some floral whorls is fairly widespread within Ranunculales). Note that there is possible variation in how calcium oxalate is synthesized, although sampling is very poor, and neither members of the ANITA grade nor of the magnoliids have been examined. Similarly, vacuolar crystal formation associated with membranes and paracrystalline bodies with widely spaced subunits is found in eudicots (crystals seem to be formed in other ways here), while in monocots there are no membrane complexes and the paracrystalline bodies have closely spaced subunits (Horner & Wagner 1995; Evert 2006). Some patterns of RNA editing may be phylogenetically informative at this level (Logacheva et al. 2008).
Recently, Jansen et al. (2006b: 37 whole chloroplast genomes, see also Zhengqiu et al. 2006), Cai et al. (2006: 35 whole chloroplast genomes, neither Chloranthales, Ceratophyllales, nor any member of Austrobaileyales included), and Duvall et al. (2006: four genes, three compartments, nuclear PHYC gene, 18S being excluded - overall, a relationships between magnoliids and monocots was preferred), Mathews (2006a: three PHY genes, 105 taxa), and Hansen et al. (2007: 61 protein-coding chloroplast genes) have also found support for this [monocot + eudicot] grouping. Jansen et al. (2006b) found support for an association of Chloranthales with the magnoliids, furthermore, Jansen et al. (2006b) and Hansen et al. (2007) found support for a sister-group relationship between Chloranthales and the magnoliids, although the analyses in Mathews (2006a) preferred an unresolved position for Chloranthales and Ceratophyllales above the Austrobaileyales, while Duvall et al. (2006) found a relationship between Chloranthales and Ceratophyllales. When sequences of complete chloroplast genomes are analysed, an association between monocots and eudicots is more strongly suggested. Thus Jansen et al. (2007) found strong support for this grouping, a number of alternative topologies being excluded, and although support for this grouping in Moore et al. (2007) was somewhat less strong, Ceratophyllum, with quite a long branch, was sister to eudicots (in some reconstructions, Piper, with a very long branch, was also involved). Similarly, Chloranthus was found to be sister to the magnoliids with moderate to strong support (Jansen et al. 2007), a position also found by Saarela et al. (2007) and many analyses in Moore et al. (2007).
Pending further studies, the set of relationships [[Chloranthales + magnoliids] [monocot [Ceratophyllales + eudicot]]] is recognised here, rather different from the relationships suggested in the first six editions of this site and also from the tree in A.P.G. II (2003) and Soltis et al. (2005b). Direct links are provided to the pages where the clades just mentioned are discussed further; this discussion will generally be just above or below where the link takes you: Ceratophyllales, Chloranthales, eudicots, and monocots.
I largely follow Ronse De Craene et al. (2003) on the insertion of floral organs.
CHLORANTHALES + MAGNOLIIDS: sesquiterpenes +; style ?hollow.
MAGNOLIIDS [MAGNOLIALES + LAURALES + CANELLALES + PIPERALES]: (neolignans +); vessels solitary and in radial multiples; leaf margins entire; A many, spiral [possible position here], extrorse, antipodal cells ephemeral, hypostase +, nucellar cap +, raphal bundle branches at the chalaza. Back to Main Tree
Caterpillars of Papilionidae-Papilioninae butterflies are notably common (almost 33% of the records) on members of this group (and Rutaceae! - similar alkaloids), although they are apparently so far unrecorded on Myristicaceae, in Laurales they predominate on Lauraceae, and in Piperales on Aristolochiaceae (see Scriber et al. 1995 for references; Zakharov et al. 2004). See Hegnauer (1990) for a discussion of the chemistry of the Polycarpicae, which includes Austrobaileyales and Ranunculales. Similar isoflavonoids are found in Magnoliaceae, Lauraceae and Chloranthaceae. For summaries of the fossil history of the group, espeacially prominent in the Mid Cretaceous and later, see Friis et al. (1997, 2006). Crown group magnoliids diverged 134.5-125.7 million years ago (Moore et al. 2007).
Although the sister group relationship of Piperales with Canellales in particular is at first sight unexpected, the magnoliid clade as a whole and the relationships within the group are turning out to be quite robust. There was not - and still really is not - much if any morphological support for this grouping (Doyle & Endress 2000; see also the characterisation above); features like tectum structure, etc., show considerable variation (J. A. Doyle 2005). However, molecular support for the clade has been increasing in successive studies (e.g. Qiu et al. 1999, 2000, 2005 [but note variability in levels of support depending on the analysis, the node sometimes collapses], 2006b; Zanis et al. 2002; Jansen et al. 2006b; Zhengqiu et al. 2006; Cai et al. 2006; Müller et al. 2006, support for [Canellales + Piperales] rather poor; Jansen et al. 2007, but little maximum parsimony support; Moore et al. 2007, but not appearing in all analyses) and includes the possession of unique indels (Löhne & Borsch 2005).
For a convenient summary of a number of features of wood anatomy, see Herendeen et al. 1999b).
MAGNOLIALES + LAURALES: cuticle waxes as annularly-ridged rodlets, palmitol
the main wax; pollen with lamellate endexine. Back to Main Tree
There is considerable variation as to how the androecium is initiated...
MAGNOLIALES Bromhead Main Tree, Synapomorphies.
Vessels in multiples; secondary phloem stratified; pith septate [with sclerenchymatous diaphragms]; nodes 3:3; petiole vasculature an arc with an adaxial plate; branching from the current innovation; leaves two-ranked, conduplicate; P whorled, G occluded by fusion and secretion, outer integument 5-10 cells across, obturator +; seeds medium-sized, testa vascularised, multiplicative; endosperm ?type, irregularly ruminate. - 5 families, 154 genera, 2929 species.
Intra- and interfamilial variation of morphological characters that have often been used to reconstruct phylogenies is considerable, in particular, Furness et al. (2002) emphasize the variability of microsporogenesis in the order. There is much discussion on character evolution in the order in Sauquet et al. (2003), and much of the character hierarchy here is based on this paper. Note, however, that where characters like extrorse/introrse anther dehiscence and ruminate/non-ruminate testa are placed on the tree depends on how the characters are optimised, or even defined (e.g. ruminate endosperm), although detailed anatomical-developmental work might clarify such issues. Furthermore, there is some conflict with the positions of characters as they are optimised on a more extensive tree for basal angiosperms - although less detailed for Magnoliales (cf. Ronse De Craene et al. 2003, also Judd et al. 2003). Doyle and Endress (2000) and Soltis et al. (2005) suggest additional characters for the clade, including palisade parenchyma, reduced fibre pit borders, foliar astrosclereids, and pollen with continuous tectum. Some of these may well need to be added to the list above.
Molecular data suggested that Myristicaceae are sister to the rest of the order, but support was only moderate (D. Soltis et al. 2000); the addition of morphological data strengthened that position, and also placed Magnoliaceae as sister to the remaining taxa (Doyle & Endress 2000), although the latter position had only moderate support (cf. P. Soltis et al. 2000; see also Sauquet et al. 2001). The family pairs Annonaceae + Eupomatiaceae and Degeneriaceae + Himantandraceae are both well supported (D. Soltis et al. 2000; P. Soltis et al. 2000; Doyle & Endress 2000). Other studies confirm these relationships (Sauquet et al. 2003; Müller et al. 2006), although Hilu et al. (2003: matK analysis alone) suggest a somewhat different set of relationships, but with poorer sampling and scanty support for the critical nodes.
For additional information, see Sugiyama (1976a, b, 1979: esp. considerable variation in cotyledonary nodal morphology), Endress (1977b, 1986a, 1994a: floral morphology), Metcalfe (1987: general anatomy), Taylor and Hickey (1995), Ronse Decraene and Smets (1996a), Kimoto and Tobe (2001), and Kim et al. (2003, 2004: AP3 and P1 genes, but note that Myristicaceae are unsampled).
Includes Annonaceae, Degeneriaceae, Eupomatiaceae, Himantandraceae, Magnoliaceae, Myristicaceae.
Synonymy: Annonales Lindley, Degeneriales C. Y Wu et al., Eupomatiales Reveal, Himantandrales Doweld & Shevyryova, Myristicales Thomé - Magnoliineae, Myristicineae Chatrou - Annonanae Doweld, Magnolianae Takhtajan - Magnoliidae Takhtajan - Magnolipsida Brongniart Magnoliid I group (Nandi et al. 1998).
MYRISTICACEAE R. Brown Back to Magnoliales
Exudate red; isoflavonoids, flavonoids diverse [flavones +], polyketides [acetogenins], (tryptamine alkaloids) +, isoquinoline alkaloids 0; sieve elements with nuclear non-dispersive protein bodies; tannin-containing tubes in the xylem; hairs branched or stellate (T-shaped); cork also in outer cortex; primary stem ± with continuous cylinder; vessel elements simple or scalariform(-reticulate); sieve tubes with non-dispersive protein bodies, (plastids with protein crystalloids and starch); petiole bundles bicollateral; (branched) sclereids or fibers +; (acicular) crystals +; cuticle waxes as platelets; (leaves spiral); plants dioecious, bracteole 1; flowers and receptacle small, P (2-)3(-5), connate; staminate flowers: A whorled (spiral), 2-40, connate (not), anthers unithecate, microsporogenesis successive, (pollen inaperturate, ulceroid, spiraperturate, ektexine granular), pollen aperture membrane sculpted, pistillode ?0; carpellate flowers: staminodes 0, G 1, 1 subbasal ovule/carpel, inner integument 3-10 cells across, (stylodium ± long); fruit a follicle dehiscing abaxially as well (indehiscent); seed large, pachychalazal, arillate (aril small), endotesta palisade, lignified, crystalliferous, tegmen vascularised, massive, exotegmen with fibers or sclerotic or tracheidal cells, chalaza with a lignified counter-palisade; endosperm nuclear, with (starch and) oil, hypocotyl not developed; n = 19, 21, 22, 25, 26; germination hypogeal.
20[list]/475: Myristica (175), Horsfieldia (100), Knema (95), Virola (60). Pantropical. (Map: from de Wilde 2000 [Indo-Malesia]; Heywood 2007).[Photo - Carpellate flower, Fruit].
Diversification within the family may be recent, within 21-15 million years before present, although this seems very recent indeed given the age of the family, it distribution throughout the humid tropics, and its apparently low dispersability (J. A. Doyle et al. 2004). Indeed, although there is a long branch leading to the family, there is little molecular divergence between its extant members (Sauquet et al. 2003).
Relationships within the family are unclear. The African and Madagascan taxa may form a clade, possibly sister to Compsoneura (but perhaps long branch attraction), overall, geography and relationships may be summarised as [[Asia] + [America] [Madagascar and Africa]]. Within the Asian/Malesian representatives, Knema and Myristica may be sister taxa. Sauquet et al. (2001, 2003), Sauquet (2003) and Sauquet and Le Thomas (2003) recently suggested that the free stamens (in some species they are numerous and apparently spirally inserted) and small aril of Mauloutchia, apparently plesiomorphic features, are likely to be derived.
There are tannin-containing tubes in the xylem, and free phloem strands in the center of the midrib bundle. The wood rays are not notably broad. The synandrium of Myristica has a sterile apex; is this axial or staminal? For the vascularisation of the ovule in Myristica fragrans, see Dickison (2000). Corner (1976) commented on the complexity of the seed coat in Myristicaceae which is as elaborate as that of any other angiosperm. Not all taxa appear to have a multiplicative testa, and some have a multiplicative tegmen. Isozyme duplication (in Myristica) suggests ancient polyploidy (Soltis & Soltis 1990).
For more information, see Hegnauer (1969, 1990: chemistry), Kerster and Baas (1981: anatomy), Kühn and Kubitzki (1993: general), de Wilde (2000: Malesian Myristicaceae), Jiménez-Rojas et al. (2002: growth patterns - Massart's model), Sauquet (2003: androecium), Chatrou (2003: apomorphies), and Sauquet and Le Thomas (2003: pollen).
Magnoliaceae [[Himantandraceae + Degeneriaceae] [Eupomatiaceae + Annonaceae]]: primary stem with distinct bundles [eustele]; wood with broad rays; flowers solitary, large, receptacle well-developed, cortical vascular system +, P = K + C, A many, spiral [possible position here], filaments with three veins, anther thecae separate, embedded in the broad filaments, the connective prolonged, G spiral, funicular obturator +; 10-aa deletion in PI-derived motif in AP3 gene.
This clade may have divsersified 120-100 million years before present (Doyle et al. 2004).
There is more than one kind of cortical vascular system in this clade (Ronse De Craene et al. 2003, see also Deroin 1999a).
MAGNOLIACEAE Jussieu Back to Magnoliales
(Deciduous); sesquiterpene lactones +; vessel elements with simple and scalariform perforation plates, (walls vestured - Liriodendron); wood fluorescing; (secondary phloem ± stratified, rays broad; sieve tube plastids with protein crystalloids and starch); nodes 6 or more:6 or more; secretory cells 0; petiole also with medullary bundles (strictly annular - Liriodendron); leaves also spiral, laterally or vertically conduplicate (supervolute-curved), stipules sheathing stem, open opposite petiole; flowers terminal or axillary; P 3 + 3 or 3 + many, K and C ± distinguishable, (A introrse - Magnolia; vein single), tapetal cells multinucleate, pollen grains boat-shaped, G 1-many, (1-)2-12(-16) ovules/carpel, fusion complete, but secretory canal, (funicular obturator +), micropyle bistomal, stigma (terminal), dry, elongate (not); fruit dry; endosperm not ruminate; n = 19.
2[list]/227: Magnolia (ca 225). The Americas (but not W. North America), and South East Asia to Malesia (Map: from Good 1974; Lozana-Contreras 1994).[Photo - Collection]
Archaeanthus, a Cenomanian fossil of some 98 million years in age from North America, may be assignable to Magnoliaceae (Dilcher & Crane 1984). Beetles are common pollinators, and the flowers may be thermogenic; floral scents of the family have been extensively studied (Azuma et al. 1999; see also Seymour 2001 for thermogenesis).
Sclerenchymatous diaphragms are particularly conspicuous in the Michelia group of Magnolia. Terminal tracheids are commonly silicified, forming distinctive phytoliths (Piperno 2006). The micropyle is exostomal in the Michelia group of Magnolia. The endexine is lamellate and the columellae fused-granular (Xu & Kirchoff 2008). Nectar is secreted from the exposed surfaces of the carpels in some species of Magnolia. When the carpels open, the seed may dangle from the fruit attached by extended annular thickenings of the protoxylem.
Generic limits around Magnolia s. str. are unclear, the genus being wildly paraphyletic (Qiu et al. 1995; Azuma et al. 2001 [section Talauma is sister to the rest of Magnolia], Kim et al. 2001a, b; Azuma et al. 2001 Nie et al. 2008 [again section Talauma is sister to the rest, but otherwise support along the backbone is poor]); it seems best to expanded the genus to encompass the whole of the current Magnolieae. The family thus includes only two genera and tribes are superfluous. In Liriodendron the leaves are lobed, with palmate secondary veins, the petiole bundle is strictly annular, the fruit is a samara, the seeds lack a sarcotesta, and the endosperm is slight and not ruminate. In Magnolia the leaves are entire, the anthers are introrse, the ovule lacks a funicular obturator(?), the dehiscence of the fruit varies, but it is not adaxial (so the fruit is not a follicle), it may dehisce abaxially, there is a sarcotesta and a scleroendotesta with crystals and lignified fibrils in the cells, and there is much endosperm. There is also a simple or tubular pore in the seed coat that marks the passage of the vascular bundle through the sclerotesta (Xu 2003). Both isozyme duplication and stomatal size increase over time suggest ancient polyploidy (Soltis & Soltis 1990; Masterson 1994).
Some information is also taken from Hegnauer (1969, 1990: chemistry), Nooteboom (1993: general), Yamada et al. (2003b: ovules), Pan et al. (2003: embryology), Xu and Rudall (2006: floral development), and Xu and Kirchoff (2008: pollen morphology); see Azuma et al. (2000), Ueda et al. (2000) and Wang et al. (2006) for molecular phlogenies, Figlar (2000) for branching patterns, Charlton (1994) and Liao and Xia (2007) for phyllotaxis and vernation, and Nooteboom (2000) for suggestions about classification. For a checklist and bibliography (under old generic names), see Frodin and Govaerts (1996).
Synonymy: Liriodendraceae F. Barkley
[Himantandraceae + Degeneriaceae] [Eupomatiaceae + Annonaceae]: anthers valvate, staminodes internal, pollen atectate, psilate, with granular infratectum, pollen tube transmission tissue differentiated; fruit indehiscent.
Doyle (2007) notes that the venation of members of this clade is often poorly differentiated and so of low rank (but cf. many Annonaceae, albeit not "basal" members) - I have not placed this character on the tree. For the inner staminodes that are often so conspicuous in the flowers, and their function in pollination - food for pollinators, attractants - see Endress (1984).
Degeneriaceae + Himantandraceae: flowers axillary; outer integument annular; x = 12.
DEGENERIACEAE I. W. Bailey & A. C. Smith Back to Magnoliales
Alkaloids 0; cork ?; vessel elements with scalariform perforation plates; sieve tube plastids with protein crystalloids and starch; nodes 5:5; petiole also with medullary bundles; secretory cells 0; cuticle waxes as platelets; leaves spiral; K 3, C many, whorled, pollen boat-shaped, G 1, basally ascidiate, occluded by fusion only, many ovules/carpel, funicle long; fruit a follicle; exotestal cells palisade, thin-walled, sarcomesotesta +, endotesta with lignified internal fibrils; embryo with 3 (4) cotyledons.
1[list]/2. Fiji, Viti Levu (map: original!).
Some information is taken from Hegnauer (1973, 1990, as Winteraceae: chemistry) and Kubitzki (1993b: general).
HIMANTANDRACEAE Diels Back to Magnoliales
Polyketide alkaloids only; vessel elements with simple (and scalariform) perforations; sieve elements with non-dispersive protein bodies; trichomes peltate; cuticle wax crystalloids 0; branching?; P or bract + bracteoles enclosing the flower in 2 series, caducous, or 2 connate + 4 connate, "C" 3-23 [staminodial], pollen scabrate, staminodes with glands, G 6-30, (1) 2 pendulous ovules/carpel; fruit ± syncarpous, a drupe with several stones; seeds flattened, testa not multiplicative, mesotesta fibrous, endotesta aerenchymatous; endosperm development?; seedling?
1 (Galbulimima)[list]/2. The Celebes, New Guinea and N.E. Australia (Map: from Hoogland 1972; Endress 1983). [Photo - Flower, Fruit, Buds, Habit]
For the testa, see Doweld and Shevyryova (1997); the ruminations are at best obscure. The perianth may be staminodial in origin; according to Johri et al. (1992) the outer integument is not vascularised.
Some information is taken from Hegnauer (1966, 1989: chemistry) and Endress (1993: general).
Eupomatiaceae + Annonaceae: sieve tube plastids with protein crystalloids and starch; rays 8-15-seriate; petiole bundles arcuate; trunk leaves spiral; inflorescence +; fruit ± berry-like; mesotesta fibrous.
EUPOMATIACEAE Endlicher Back to Magnoliales
Also rhizomatous, woody, with xylopodium or root tubers; pith not septate; vessel elements with scalariform perforation plates; secondary phloem?; sieve tubes with non-dispersive protein bodies [check], plastids also with protein rods; nodes (5-)7(-11):(5-)7(-11); secretory cells +; prophyll adaxial; (stomata anomocytic); branching?; flowers fasciculate; receptacle concave, calyptra +, thick, deciduous, with sclereids, P 0, A introrse, pollen with encircling equatorial sulcus, petaloid staminodes 15+, connate basally and with fertile stamens, with many glands, G many, ± connate, occluded by fusion only, placentation sublaminar, 2-11 ovules/carpel, stigma flat, papillate; aggregate fruit +; testa ?not vascularised, exotestal cells with thickened unlignified walls, endotesta unlignified, exotegmic cells cuboid, slightly lignified, endotegmic cells enlarged, crushed; n = 10; germination epigeal/phanerocotylar.
1[list]/3. New Guinea and E. Australia (Map: from Hoogland 1972; Endress 1983). [Photos - Flower, Flower]
The main axes are mixed, initially being orthotropic and bearing spirally-arranged leaves, later being more or less plagiotropic and with distichous leaves. There are about 3 two-ranked bracts on the pedicel; the calyptra itself is often interpreted as being a modified, amplexicaul bract (e.g. Endress 2003b; esp. Kim et al. 2005b), although it might seem that such a dramatic change in leaf insertion was unlikely. There is no evidence of isozyme duplication (Soltis & Soltis 1990).
Some information is taken from Hegnauer (1966, 1989: chemistry), Endress (1993: general) and Rix and Endress (2007 - an easy account).
ANNONACEAE Jussieu Back to Magnoliales
Vessel elements with simple perforation plates; epidermal cells with single crystals [?level]; flowers with open development; A whorled, filaments with a single vein; endotestal plug +; tegmen crushed, ruminations irregular.
129/2220 [list] - three groups below. Largely tropical.
1. Anaxagorea
Uniseriate hairs terminate in a rounded cell; trunk leaves distichous; (petiole vascular tissue ± annular; with adaxial bicollateral plate); receptacular vascular system 0; fruit a follicle; endotesta aerenchymatous, tegmen alone involved in ruminations, with idioblastic oil globules; n = 8.
1/21. Tropical America, also Sri Lanka to West Malesia (Map: from Aubréville 1974a). [Photo - Flower, Fruit, Fruit.]
There can be three, separate bundles in the petiole (Jovet-Ast 1942). The pollen endexine is lamellated. The follicle is explosively dehiscent.
For a molecular phylogeny of Anaxagorea that is integrated with morphological variation, see Scharaschkin and Doyle (2005, 2006).
The Ambavia group + The Rest: internal staminodes 0; amyloid in endosperm [brown-violet stain] +. (Map: from Aubréville 1974a.)
2. The Ambavia clade
Anther connective ± tongue-like, (carpel stipe articulated), ovules (1)2/carpel, integuments 3; n = 7.
6? (Ambavia, Cleistopholis, Tetrameranthus, Lettowianthus, Meiocarpidium, Mezzettia, Cananga, Cleistopholis)/54: Cyathocalyx (36: ?paraphyletic). Tropical, inc. Madagascar.
3. The Rest
(Lianes; shrubs; deciduous); acetogenins [antimicrobial] +, neolignans 0?; terminal cell of uniseriate hairs pointed (hairs stellate); (primary stem with continuous cylinder); cambium storied; (sieve tube plastids also with protein fibers); petiole bundle also annular; branched sclereids or fibers common; secretory cells +; (prophyll adaxial), petioles short; inflorescence cymose (leaf opposed), or flowers axillary (medium in size), (2-)3(-4)-merous, P usu. 3 [smaller] + 3 + 3, very thick, often valvate, A (³3), (latrorse, introrse), anther connective peltate-truncate, (thecae septate), tapetal cells plasmodial, multinucleate (microsporogenesis successive; pollen with circular sulcus; ektexine columellate), G (3-)many (syncarpous; parietal placentation), spiral, when 3 opposite outer P, 1-many (tritegmic) ovules/carpel (nucellar cap 0), stigma capitate to U-shaped, wet; fruit berrylets (follicles; carpels coalescent); seeds (with micropylar aril), ruminations regular, also involving testa, mesotesta of crossed fibers (sarcotesta), endotesta crystalliferous (with thin walled, longitudinal fibers); endosperm ruminations mostly regularly spiniform or lamelliform; n = (7) 8-9; germination epigeal/crypto- or phanerocotylar.
3a. The Short Branch Clade
(Pollen globose, ± spingy, disulcate).
Polyalthia (150: for limits, see Mols et al. 2008a), Pseuduvaria (50: see Su & Saunders 2006; Su et al. 2008), Unoniopsis (45). Lowland tropics.
3b. The Long Branch Clade
(Clade A: Trunk leaves distichous; pollen in tetrads or polyads).
Guatteria (280: much diversification in (Amazonian) South America perhaps 8.8-4.9 million years before present, moved to South America from Central America, see Erkens 2007; Erkens et al. 2007a, b), Annona (120-175, soursop, sweetsop: inc. Rollinia), Xylopia (100-160), Uvaria (110-150: polyphyletic, see Mols et al. 2004), Artabotrys (100), Goniothalamus (50-120), Duguetia (70-95), Fissistigma (60), Monanthotaxis (55), Friesodielsia (50-60: ?monophyletic). Predominantly lowland tropics, rarely temperate.
"The rest" is made up of two major clades, the Malmea-Piptostima-Miliusa (MPM) clade, including a probably polyphyletic Polyalthia, which shows relatively little internal molecular divergence (the short branch clade of Richardson et al. 2004) and is not very speciose, mostly lacking large genera aside from Polyalthia. Mols et al. (2008b) explore character evolution within the miliusoid clade. The other main clade is the inaperturate pollen clade, in which there is more molecular divergence (the long branch clade); it includes Artobotrys, Guatteria, Xylopia, Annona, etc. (the latter is in clade A above: see also J. A. Doyle et al. 2004; Pirie et al. 2005). Details of the groupings need to be worked up, and limits of genera and numbers of included species seem particularly uncertain.
Stem Annonaceae may be about 91-82 ± 4 million years old (Wikström et al. 2001), while diversification may have occured 82-57 million years before present (Doyle et al. 2004; Scharaschkin & Doyle 2005 [84 million years before present]). J. A. Doyle et al. (2004) and Richardson et al. (2004) discuss the historical biogeography of the family; the stem node of the [long + short branch clades] may date to 70-65 million years before present and the crown node to 66.7-56.6 ± 2.3 million years before present - in any event, largely post drift in age. Richardson et al. (2004) provide many other details of the diversification of these two clades; New World members of the short branch clade form a monophyletic group (Pirie et al. 2006). Divergence within Anaxagorea may have begun ca 44 million years before present (Scharaschkin & Doyle 2005).
In Neotropical Annonaceae pollination of the more or less odorous flowers is predominantly by a variety of beetles, although pollination by flies (e.g. Su et al. 2008) and thrips is also known; beetle pollination is common throughout the range of the family. It has been suggested that the tough, expanded connective that predominates in group 3 above may potect the pollen from the depradations of unwanted visitors (Gottsberger 1999; Silberbauer-Gottsberger et al. 2003). The flowers of some Annonaceae show thermogenesis (Seymour 2001). Dispersal of fruit is predominantly by mammals and birds.
Cork in the roots of Goniothalamus may be superficial (Blunden & Kyi 1974). The wood occasionally fluoresces. Terminal tracheids are fairly commonly silicified (Piperno 2006). The main axes of Annonaceae are often mixed (?Troll's model), initially being orthotropic and with spirally-arranged leaves, later being more or less plagiotropic and distichous (see also Eupomatia). Tetrameranthus sometimes seems to have opposite leaves; according to George Schatz (pers. comm.) it lacks plagiotropic branches and has all branches with spirally-arranged leaves. In some Xylopia, etc., the plagiotropic branch systems are frondose and very beautiful. Some Old World taxa are lianes. Thus the ultimate branches of Artabotrys have curved hooks which represent modified inflorescences; the orthtropic stems may bear stout, paired and rather vicious thorns. Xylopia, like Anaxagorea also with staminodes and follicles, has micropylar-arillate seeds (Corner 1976: other genera may also have reduced arils - see Svoma 1997). Reports that the micropyle is formed by both integuments need to be confirmed (cf. Svoma 1998b). Monodora (derived) has a rather thin outer integument.
The position of Unonopsis on the tree has been somewhat erratic, probably because of ancient paralogy (Pirie et al. 2007).
Additional information is taken from Jovet-Ast (1942: indumentum and anatomy), van der Wyck and Canright (1956: anatomy), Hegnauer (1964, 1989: chemistry), Okada and Ueda (1984: cytology), Morawaetz (1986, 1988: esp. cytology), Christmann (1986: seed anatomy), van Heusden (1992: floral morphology), Kessler (1993: general), Doyle and le Thomas (1994, 1996: morphological phylogeny), Rudall and Furness (1997: tapetum), Svoma (1998a: seeds), Svoma (1998b: ovules), Deroin (1999a: receptacular vascular system), Doyle et al. (2000: pollen evolution), Bakker (2000a, b: general); Johnson (2003: leaf insertion), Silberbauer-Gottsberger et al. (2003: pollination), Junikka and Koek-Noorman (2007: bark anatomy), Couvreur et al. (2008: evolution of syncarpy, etc.), and Sun et al. (2008: epidermal anatomy).
Synonymy: Hornschuchiaceae J. Agardh, Monodoraceae J. Agardh
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