EXTANT SEED PLANTS

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 rich in guaiacyl units; true roots present, apex multicellular, xylem exarch, branching endogenous; arbuscular mycorrhizae +; shoot apical meristem multicellular, interface specific plasmodesmatal network; 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 mm/mm² [mean for all non-angiosperms 1.8]; plant heterosporous, sporangia eusporangiate, on sporophylls, sporophylls aggregated in indeterminate cones/strobili; true pollen [microspores, i.e. no distal pore for release of gametes] +, 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 [N/O//A/C and P//BE lines], 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 in 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 a sieve plate and cytoplasm with P-proteins, companion cells from same mother cell that gave rise to the sieve tube; nodes unilacunar [1:?]; stomata with ends of guard cells level with pore, paracytic, outer stomatal ledges producing vestibule; leaves with petiole and lamina [the latter formed from the primordial leaf apex], development of venation acropetal, 2ndary veins pinnate, fine venation reticulate, veins (1.7-)4.1(-5.7) mm/mm², endings free; flowers perfect, polysymmetric, parts spiral [esp. the A], free, development in general centripetal, numbers unstable; P not sharply 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, ektexine 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 , 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 four-celled [one-modular, nucleus of egg cell sister to one of the polar nuclei], stylulus short, hollow, stigma ± decurrent, dry [not 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, minute; 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 + C/PHYB + E gene pairs.

Evolution. Possible apomorphies for flowering plants 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, there is considerable variation between families in particular for several of these characters, and also because details of relationships among gymnosperms will affect the level at which some of these characters are pegged. For example, if reticulate-perforate pollen is optimized to the next node on the tree (see Friis et al. 2009 for a discussion), it effectively makes the pollen morphology of the common ancestor of all angiosperms ambiguous....

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

ERICALES [ASTERID I + II]: ovules tenuinucellate.

ASTERID I + II: ellagic acid 0, proanthocyanidins not common; inflorescence cymose; C forming a distinct tube; A epipetalous, = and opposite sepals or P [polyandry (secondary) very uncommon indeed].

ASTERID II: Myricetin 0; vessel elements with scalariform perforation plates; flowers rather small, style short; endosperm copious, embryo short/very short.

ASTERALES [ESCALLONIALES [BRUNIALES [APIALES [PARACRYPHIALES + DIPSACALES]]]]: iridoids +; inflorescence?; C tube initiation early; G [2-3], inferior.

ESCALLONIALES [BRUNIALES [APIALES [PARACRYPHIALES + DIPSACALES]]]: ?

BRUNIALES [APIALES [PARACRYPHIALES + DIPSACALES]]: ?

BRUNIALES Dumortier  Main Tree, Synapomorphies.

Plant woody, evergreen; iridoids?; nodes 1:1; flowers polysymmetric, anthers basifixed; G position?, ovules weakly crassinucellate. - 2 families, 14 genera, 79 species.

Phylogeny. Backlund (1996) included Bruniaceae and Columelliaceae in Dipsacales, but other relationships have been suggested (Gustafsson et al. 1996; Backlund & Bremer 1997; Pyck & Smets 2000; Bell et al. 2001). For the possible association of Bruniaceae with Asterales, see Lundberg (2001e). A position of Columelliaceae s.l. (inc. Desfontainiaceae), in or near Dipsacales was suggested by Bremer et al. (2001) and especially by Lundberg (2001e), although the support was at best moderate. Indeed, Bruniaceae are sister (1.0 Bayesian p.p.) to Columelliaceae in many analyses in Winkworth et al. (2008a), although not when coding coding chloroplast sequences were used alone, and so this where they are placed now. Both palynology and wood anatomy had suggested a relationship between Columellia and Desfontainia (ex Loganiaceae) (Mennenga, in Leeuwenberg 1980), and this was strongly supported by rbcL and other data (see B. Bremer et al. 1994; Backlund & Bremer 1997; Bell et al. 2001).

Previous Relationships. In the first eight versions of this site (pre April 2008) it was thought appropriate to place Columelliaceae s.l. (= [Columelliaceae + Desfontainiaceae]) immediately before the ordinal characterisation of Dipsacales as it made morphological "sense". For instance, they all have opposite leaves, and Columellia has amoeboid tapetum (cf. Bremer et al. 2001) like Dipsacales although Desfontainia does not (Maldonado de Magnano 1986a). If the pair are not immediately related to Dipsacales, as now seems probable, the substantial similarity that they have with Dipsacales may indicate either substantial homoplasy or a suite of lower-level synapomorphies in the asterid II group of which there is currently no indication; the latter is less likely.

Indeed, various families have been placed here or elsewhere in the asterid II clade, but with uncertain support; recent work is clarifying their relationships (Winkworth et al. 2008a; Tank & Donoghue 2009). For Polyosmaceae and Escalloniaceae, here as Escalloniaceae, see Escalloniales; Paracryphiaceae, Quintiniaceae, and Sphenostemonaceae are combined as Paracryphiaceae and form a clade sister to Dipsacales; while Columelliaceae and Bruniaceae, together making up Bruniales, are dealt with below.

Includes Bruniaceae, Columelliaceae.

Synonymy: Columelliales Doweld, Brunianae Doweld

BRUNIACEAE de Candolle, nom. cons.   Back to Bruniales

Ericoid shrubs; myricetin +, iridoids?; stomata cyclocytic, orientation transverse; leaves spiral, margins entire, apex glandular, stipules colleter-like or 0; inflorescence spicate or (involucrate and) capitate (flowers single); flowers often small, (4-merous), (K connate), C often clawed (connate); A (adnate to C), anthers sagittate (not Audouinia), pollen 3-10 colporate, disc +/0, G 1 or [2 (3)], inferior, (superior), ?oblique, placentation apical-axile, 1-4(-12) pendulous ovules/carpel, micropyle long, endothelium 0, hypostase +, (styles +, style 0), stigma capitate; fruit a schizocarp, achenial or nut-like, single-seeded, or capsule, also splitting adaxially, K persistent; seed (arillate), coat ?; endosperm type?, haustoria?; n = 10-11 (21, 23).

12[list]/75. South Africa, almost entirely the Cape Province, also KwaZulu-Natal (map: from Claßen-Bockhoff 2000). [Photo - Flowers.]

• Bruniaceae are ericoid shrubs from the Cape region of South Africa that can be recognised by an often black projection at the apex of the entire leaf blade; the leaves are spirally arranged. The often small flowers are frequently aggregated into more or less capitate inflorescences, the adaxial surfaces of the petals showing a diversity of swellings or ridges. The ovary is more or less inferior.

Evolution. There is a striking similarity between the flowers of Actinocalyx, from the Upper Cretaceous (Santomasian/Campanian) of Sweden, and those of Bruniaceae (Hall 1987). Stem group Bruniaceae may be up to 107 million years old, although probably somewhat less, yet much diversification within the clade has occured within the last 20 million years (Quint & Claßssen-Bockhoff 2008).

Chemistry, Morphology, etc. Bruniaceae are poorly known. The leaf apex has suberised cells produced by a localised cork cambium. The corolla "tube" is at least sometimes formed by adnation of the filaments to adjacent free petals, but the petals are developmentally initally free (Quint & Claßssen-Bockhoff 2006b). The androecium is often weakly monosymmetric, the abaxial pair of stamens being larger than the others. Gynoecial variation is considerable; in genera like Berzelia where there is only a single carpel (really pseudomonomery?), there is only a single locule, ovule and style. The ovules may be pleurotropous (van Tieghem 1898), and there are only one or two cells between the megaspore mother cells and the nucellar epidermis.

Some information is taken from from Saxton (1910 - no endothelium is shown), Jay (1968a: chemistry), Hall (1988: pollen), Dahlgren and van Wyk (1988), Gregory (1998: anatomy), Endress and Stumpf (1991), Claßssen-Bockhoff (2000: detailed discussion of inflorescences), and Quint and Claßssen-Bockhoff (2006b: floral ontogeny); for wood anatomy, see Carlquist (1978b).

Phylogeny. There is strongly supported phylogenetic stucture within the family: [Linconieae (Linconia only, anther thecae apically connate and sterilised) [Audoinieae (anther thecae adnate to connective their entire length) + Brunieae]] (Quint & Claßssen-Bockhoff 2006a).

Classification. For a somewhat dated monograph, see Pillans (1947).

Previous Relationships. Bruniaceae have often been linked with the South African Grubbiaceae, here in Cornales (see Hall 1987 for some references), but the similarities between the two probably reflect the fact that they grow in similar habitats.

Synonymy: Berzeliaceae Nakai

COLUMELLIACEAE D. Don, nom. cons.   Back to Bruniales

Cork cambium deep-seated; pericyclic fibers 0; petiole bundles arcuate; bud without scales; leaves opposite, petiole bases meeting, margins gland-toothed; inflorescence terminal, cymose; flowers medium-sized, anther connective well-developed, style long, many ovules/carpel, endothelium poorly developed; K persistent in fruit; seeds many, anticlinal exotestal cells much thickened, with plasmodesmata.

2[list]/5. Costa Rica to Chile, montane in the tropical part of this area.

Columellia Ruíz & Pavón

Shrubs or trees; plant bitter tasting, iridoids 0; central petiole bundle much the largest; cuticle waxes as tubules; leaves (with glands on lower surface), teeth glandular (0); flowers (4-8-merous), K ± valvate; A 2, latrorse, thecae semicircular, attached their length to expanded connective, tapetum amoeboid; G [2], largely inferior, placentation intrusive parietal or lobed-axile, ovules ?tenuinucellate?, stigma with two broad lobes, almost cup-like; fruit septicidal and part loculicidal down the sides; exotestal cells elongated; endosperm type?; n = ?

1/4. S. Colombia to Bolivia, in the Andes (map: from Brizicky 1961). [Photo - Flower]

Desfontainia Ruíz & Pavón

Shrubs; route I secoiridoids +, tannin 0; scattered sclereids in the pericyclic position; leaves conduplicate, teeth spiny, colleters +; flowers usu. single; K connate at base, C contorted, A adnate in throat, filaments stout, thecae ± embedded in connective, G [5(-7)], opposite petals, placentation axile but apically parietal, integument 6-9 cells across, stigma only slightly expanded; fruit a berry; exotestal cells polygonal, outer walls pectic, other walls, especially anticlinal, lignified; endosperm haustoria small; n = 7.

1/1: Desfontainia spinosa. Costa Rica to Chile. [Photo - Flower]

Evolution. Yet another old, species poor but morphologically quite diverse clade along the spine of the atsreid I + II clade that occurs in South America....

Chemistry, Morphology, etc. The intervascular pits of Desfontainia are scalariform or circular and bordered, not vestured. All the cells in even the young stem are slightly lignified. Myricetin? The two stamens of Columellia are the adaxial pair and have latrorse, semicircular thecae attached their length to an expanded connective; the anthers are described as being extrorse by Backlund and Donoghue (1996). Although both Desfontainia and Viburnum have similar, smooth pollen orbicules, these are quite widely distributed in Gentianales, at least (Vinckier & Smets 2002). Maldonado de Magnano (1986a) suggests that the ovules of Desfontainea are weakly crassinucellate, with a single layer of nucellar cells between the megaspore and the nucellar epithelium; an endothelium is at most poorly developed, and there is a large haustorial suspensor.

For Columellia information was taken from Hasselberg (1937), Stern et al. (1969: anatomy), Backlund and Donoghue (1996: general), and Gregory (1998: anatomy), for waxes, see Theisen and Barthlott (1994) and Fehrenbach and Barthlott (1988: cuticle platelets as ribbons and rodlets). Further data from: Zak & Jaramillo 3266. For Desfontainia information was taken from Backlund and Donoghue (1996) and Hasselberg (1937). Further data from: Qin 710 and Zarucchi et al. 5195.

Previous Relationships. The relationships of Columelliaceae have long been uncertain; the family was placed in Rosales by Cronquist (1981) and in Hydrangeales by Takhtajan (1997). Desfontainiaceae have usually been considered to be entirely unrelated and included in the heterogeneous Loganiaceae.