EMBRYOPSIDA Pirani & Prado
Gametophyte dominant, independent, multicellular, not motile, initially ±globular; showing gravitropism; acquisition of phenylalanine lysase [PAL], phenylpropanoid metabolism [lignans +, flavonoids + (absorbtion of UV radiation)], xyloglucans in primary cell wall, side chains charged; plant poikilohydrous [protoplasm dessication tolerant], ectohydrous [free water outside plant physiologically important]; thalloid, leafy, with single-celled apical meristem, tissues little differentiated, rhizoids +, unicellular; chloroplasts several per cell, pyrenoids 0; glycolate metabolism in leaf peroxisomes [glyoxysomes]; centrioles/centrosomes in vegetative cells 0, microtubules with γ-tubulin along its length [?here], interphase microtubules form hoop-like system; metaphase spindle anastral, predictive preprophase band of microtubules [where cell plate will join parental cell wall], phragmoplast + [cell wall deposition spreading from around the spindle fibres], plasmodesmata +; antheridia and archegonia jacketed, surficial; blepharoplast +, centrioles develop de novo, bicentriole pair coaxial, separate at midpoint, centrioles rotate, associated with basal bodies of cilia, multilayered structure + [4 layers: L1, L4, tubules; L2, L3, short vertical lamellae] (0), spline + [tubules from L1 encircling spermatid], basal body 200-250 nm long, associated with amorphous electron-dense material, microtubules in basal end lacking symmetry, stellate array of filaments in transition zone extended, axonemal cap 0 [microtubules disorganized at apex of cilium]; male gametes [spermatozoids] with a left-handed coil, cilia 2, lateral; oogamy; sporophyte multicellular, cuticle +, plane of first cell division transverse [with respect to long axis of archegonium/embryo sac], sporangium and upper part of seta developing from epibasal cell [towards the archegonial neck, exoscopic], with at least transient apical cell [?level], initially surrounded by and dependent on gametophyte, placental transfer cells +, in both sporophyte and gametophyte, wall ingrowths develop early; suspensor/foot +, cells at foot tip somewhat haustorial; sporangium +, single, terminal, dehiscence longitudinal; meiosis sporic, monoplastidic, MTOC [MTOC = microtubule organizing centre] associated with plastid, sporocytes 4-lobed, cytokinesis simultaneous, preceding nuclear division, quadripolar microtubule system +; wall development both centripetal and centrifugal, sporopollenin + laid down in association with trilamellar layers [white-line centred lamellae; tripartite lamellae], >1000 spores/sporangium; nuclear genome size <1.4 pg, main telomere sequence motif TTTAGGG, LEAFY and KNOX1 and KNOX2 genes present, ethylene involved in cell elongation; chloroplast genome with close association between trnLUAA and trnFGAA genes, precursor for starch synthesis in plastid.
Many of the bolded characters in the characterization above are apomorphies of subsets of streptophytes along the lineage leading to the embryophytes, not apomorphies of crown-group embryophytes per se.
All groups below are crown groups, nearly all are extant. Characters mentioned are those of the immediate common ancestor of the group,  contains explanatory material, () features common in clade, exact status unclear.
Abscisic acid, L- and D-methionine distinguished metabolically; sporophyte with polar transport of auxins, class 1 KNOX genes expressed in sporangium alone; sporangium wall 4≤ cells across [≡ eusporangium], tapetum +, secreting sporopollenin, which obscures outer white-line centred lamellae, columella +, developing from endothecial cells; stomata +, on sporangium, anomocytic, cell lineage that produces them with symmetric divisions [perigenous]; underlying similarities in the development of conducting tissue and of rhizoids/root hairs; spores trilete; shoot meristem patterning gene families expressed; MIKC, MI*K*C* genes, post-transcriptional editing of chloroplast genes; gain of three group II mitochondrial introns, mitochondrial trnS(gcu) and trnN(guu) genes 0.
[Anthocerophyta + Polysporangiophyta]: gametophyte leafless; archegonia embedded/sunken [on;y neck protruding]; sporophyte long-lived, chlorophyllous; cell walls with xylans.
Sporophyte well developed, branched, branching apical, dichotomous, potentially indeterminate; hydroids +; stomata on stem; sporangia several, terminal; spore walls not multilamellate [?here].
Vascular tissue + [tracheids, walls with bars of secondary thickening].
EXTANT TRACHEOPHYTA / VASCULAR PLANTS
Sporophyte with photosynthetic red light response; (condensed or nonhydrolyzable tannins/proanthocyanidins +); plant homoiohydrous [water content of protoplasm relatively stable]; control of leaf hydration passive; plant endohydrous [physiologically important free water inside plant]; (condensed or nonhydrolyzable tannins/proanthocyanidins +); xyloglucans with side chains uncharged [?level], in secondary walls of vascular and mechanical tissue; lignins +; stem apex multicellular, with cytohistochemical zonation, plasmodesmata formation based on cell lineage; tracheids +, in both protoxylem and metaxylem, G- and S-types; sieve cells + [nucleus degenerating]; endodermis +; leaves/sporophylls spirally arranged, blades with mean venation density ca 1.8 mm/mm2 [to 5 mm/mm2], all epidermal cells with chloroplasts; sporangia adaxial, columella 0; tapetum glandular; ?position of transfer cells; MTOCs not associated with plastids, basal body 350-550 nm long, stellate array in transition region initially joining microtubule triplets; suspensor +, shoot apex developing away from micropyle/archegonial neck [from hypobasal cell, endoscopic], root lateral with respect to the longitudinal axis of the embryo [plant homorhizic].[MONILOPHYTA + LIGNOPHYTA]
Sporophyte endomycorrhizal [with Glomeromycota]; growth ± monopodial, branching spiral; roots +, endogenous, positively geotropic, root hairs and root cap +, protoxylem exarch, lateral roots +, endogenous; G-type tracheids +, with scalariform-bordered pits; leaves with apical/marginal growth, venation development basipetal, growth determinate; sporangium dehiscence by a single longitudinal slit; cells polyplastidic, MTOCs diffuse, perinuclear, migratory; blepharoplasts +, paired, with electron-dense material, centrioles on periphery, male gametes multiciliate; chloroplast long single copy ca 30kb inversion [from psbM to ycf2]; LITTLE ZIPPER proteins.
Sporophyte woody; stem branching lateral, meristems axillary; lateral root origin from the pericycle; cork cambium + [producing cork abaxially], vascular cambium bifacial [producing phloem abaxially and xylem adaxially].
Plants heterosporous; megasporangium surrounded by cupule [i.e. = unitegmic ovule, cupule = integument]; pollen lands on ovule; megaspore germination endosporic [female gametophyte initially retained on the plant].
EXTANT SEED PLANTS / SPERMATOPHYTA
Plant 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]; lignin chains started by monolignol dimerization [resinols common], particularly with guaiacyl and p-hydroxyphenyl [G + H] units [sinapyl units uncommon, no Maüle reaction]; root stele diarch to pentarch, xylem and phloem originating on alternating radii, cork cambium deep seated; stem apical meristem complex [with quiescent centre, etc.], plasmodesma density in SAM 1.6-6.2[mean]/μm2 [interface-specific plasmodesmatal network]; eustele +, protoxylem endarch, endodermis 0; 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 +; cork cambium superficial; leaf nodes 1:1, a single trace leaving the vascular sympodium; leaf vascular bundles amphicribral; guard cells the only epidermal cells with chloroplasts, stomatal pore with active opening in response to leaf hydration, control by abscisic acid, metabolic regulation of water use efficiency, etc.; axillary buds +, exogenous; prophylls two, lateral; leaves with petiole and lamina, development basipetal, lamina simple; sporangia borne on sporophylls; spores not dormant; microsporophylls aggregated in indeterminate cones/strobili; grains monosulcate, aperture in ana- position [distal], primexine + [involved in exine pattern formation with deposition of sporopollenin from tapetum there], exine and intine homogeneous, exine alveolar/honeycomb; ovules with parietal tissue [= crassinucellate], megaspore tetrad linear, functional megaspore single, chalazal, sporopollenin 0; gametophyte ± wholly dependent on sporophyte, development initially endosporic [apical cell 0, rhizoids 0, etc.]; male gametophyte with tube developing from distal end of grain, male gametes two, developing after pollination, with cell walls; female gametophyte initially syncytial, walls then surrounding individual nuclei; embryo cellular ab initio, suspensor short-minute, embryonic axis straight [shoot and root at opposite ends; plant allorhizic], cotyledons 2; embryo ± dormant; ycf2 gene in inverted repeat, mitochondrial trans- nad2i542g2 and coxIIi3 introns present; whole nuclear genome duplication [ζ - zeta - duplication], two copies of LEAFY gene, PHY gene duplications [three - [BP [A/N + C/O]] - copies], 5.8S and 5S rDNA in separate clusters.
ANGIOSPERMAE / MAGNOLIOPHYTA
Lignans, O-methyl flavonols, dihydroflavonols, triterpenoid oleanane, apigenin and/or luteolin scattered, [cyanogenesis in ANA grade?], lignin also with syringyl units common [G + S lignin, positive Maüle reaction - syringyl:guaiacyl ratio more than 2-2.5:1], hemicelluloses as xyloglucans; root apical meristem intermediate-open, pith relatively inconspicuous, lateral roots initiated immediately to the side of [when diarch] or opposite xylem poles; origin of epidermis with no clear pattern [probably from inner layer of root cap], trichoblasts [differentiated root hair-forming cells] 0, hypodermis suberised and with Casparian strip [= exodermis]; shoot apex with tunica-corpus construction, tunica 2-layered; 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, not occluding pores of plate, companion cell and sieve tube from same mother cell; ?phloem loading/sugar transport; nodes 1:?; dark reversal Pfr → Pr; protoplasm dessication tolerant [plant poikilohydric]; stomata brachyparacytic [ends of subsidiary cells level with ends of pore], outer stomatal ledges producing vestibule, reduction in stomatal conductance with increasing CO2 concentration; lamina formed from the primordial leaf apex, margins toothed, development of venation acropetal, overall growth ± diffuse, secondary veins pinnate, fine venation hierarchical-reticulate, (1.7-)4.1(-5.7) mm/mm2, vein endings free; flowers perfect, pedicellate, ± haplomorphic, protogynous; parts free, numbers variable, development centripetal; P +, ?insertion, members each with a single trace, outer members not sharply differentiated from the others, not enclosing the floral bud; A many, filament not sharply distinguished from anther, stout, broad, with a single trace, anther introrse, tetrasporangiate, sporangia in two groups of two [dithecal], each theca dehiscing longitudinally by a common slit, ± embedded in the filament, walls with at least outer secondary parietal cells dividing, endothecium +, cells elongated at right angles to long axis of anther; tapetal cells binucleate; microspore mother cells in a block, microsporogenesis successive, walls developing by centripetal furrowing; pollen subspherical, tectum continuous or microperforate, ektexine columellate, endexine lamellate only in the apertural regions, thin, compact, intine in apertural areas thick, pollenkitt +; nectary 0; carpels present, superior, free, several, ascidiate [postgenital occlusion by secretion], stylulus at most short [shorter than ovary], hollow, cavity not lined by distinct epidermal layer, stigma ± decurrent, carinal, dry; suprastylar extragynoecial compitum +; 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, nucellar cap?; megasporocyte single, hypodermal, functional megaspore lacking cuticle; female gametophyte lacking chlorophyll, not photosynthesising, 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 grains land on stigma, bicellular at dispersal, mature male gametophyte tricellular, germinating in less than 3 hours, pollen tube elongated, unbranched, growing between cells, growth rate (20-)80-20,000 µm/hour, apex of pectins, wall with callose, lumen 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, ciliae 0, siphonogamy; double fertilization +, ovules aborting unless fertilized; P deciduous in fruit; mature seed much larger than fertilized ovule, small , dry [no sarcotesta], exotestal; endosperm +, cellular, development heteropolar [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, embryo short [<¼ length of seed]; plastid and mitochondrial transmission maternal; Arabidopsis-type telomeres [(TTTAGGG)n]; nuclear genome very small [1C = <1.4 pg, mean 1C = 18.1 pg, 1 pg = 109 base pairs], whole nuclear genome duplication [ε/epsilon event]; 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, palaeo AP3 and PI genes [paralogous B-class genes] +, with "DEAER" motif, SEP3/LOFSEP and three copies of the PHY gene, [PHYB [PHYA + PHYC]]; chloroplast chlB, -L, -N, trnP-GGG genes 0.
[NYMPHAEALES [AUSTROBAILEYALES [[CHLORANTHALES + MAGNOLIIDS] [MONOCOTS [CERATOPHYLLALES + EUDICOTS]]]]]: 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]]]]: phloem loading passive, via symplast, plasmodesmata numerous; vessel elements with scalariform perforation plates in primary xylem; essential oils in specialized cells [lamina and P ± pellucid-punctate]; tension wood + [reaction wood: with gelatinous fibres, g-fibres, on adaxial side of branch/stem junction]; tectum reticulate; anther wall with outer secondary parietal cell layer dividing; nucellar cap + [character lost where in eudicots?]; 12BP [4 amino acids] deletion in P1 gene.
[[CHLORANTHALES + MAGNOLIIDS] [MONOCOTS [CERATOPHYLLALES + EUDICOTS]]] / MESANGIOSPERMAE: benzylisoquinoline alkaloids +; sesquiterpene synthase subfamily a [TPS-a] [?level], 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 [?here]; pollen tube growth intra-gynoecial; extragynoecial compitum 0; carpels plicate [?here]; embryo sac bipolar, 8 nucleate, antipodal cells persisting; endosperm triploid.
[MONOCOTS [CERATOPHYLLALES + EUDICOTS]]: (extra-floral nectaries +); (veins in lamina often 7-17 mm/mm2 or more [mean for eudicots 8.0]); (stamens opposite [two whorls of] P); (pollen tube growth fast).
[CERATOPHYLLALES + EUDICOTS]: ethereal oils 0.
EUDICOTS: (Myricetin, delphinidin +), asarone 0 [unknown in some groups, + in some asterids]; root epidermis derived from root cap [?Buxaceae, etc.]; (vessel elements with simple perforation plates in primary xylem); nodes 3:3; stomata anomocytic; flowers (dimerous), cyclic; protandry common; K/outer P members with three traces, ("C" +, with a single trace); A ?, filaments fairly slender, anthers basifixed; microsporogenesis simultaneous, pollen tricolpate, apertures in pairs at six points of the young tetrad [Fischer's rule], cleavage centripetal, wall with endexine; G with complete postgenital fusion, stylulus/style solid [?here]; seed coat?
[PROTEALES [TROCHODENDRALES [BUXALES + CORE EUDICOTS]]]: (axial/receptacular nectary +).
[TROCHODENDRALES [BUXALES + CORE EUDICOTS]]: benzylisoquinoline alkaloids 0; euAP3 + TM6 genes [duplication of paleoAP3 gene: B class], mitochondrial rps2 gene lost.
[BUXALES + CORE EUDICOTS]: ?
CORE EUDICOTS / GUNNERIDAE: (ellagic and gallic acids +); leaf margins serrate; compitum + [one position]; micropyle?; γ whole nuclear genome duplication [palaeohexaploidy, gamma triplication], PI-dB motif +, small deletion in the 18S ribosomal DNA common.
[ROSIDS ET AL. + ASTERIDS ET AL.] / PENTAPETALAE: root apical meristem closed; (cyanogenesis also via [iso]leucine, valine and phenylalanine pathways); flowers rather stereotyped: 5-merous, parts whorled; P = calyx + corolla, the calyx enclosing the flower in bud, sepals with three or more traces, petals with a single trace; stamens = 2x K/C, in two whorls, internal/adaxial to the corolla whorl, alternating, (numerous, but then usually fasciculate and/or centrifugal); pollen tricolporate; G , G  also common, when [G 2], carpels superposed, placentation axile, style +, stigma not decurrent; compitum +; endosperm nuclear; fruit dry, dehiscent, loculicidal [when a capsule]; RNase-based gametophytic incompatibility system present; floral nectaries with CRABSCLAW expression; (monosymmetric flowers with adaxial/dorsal CYC expression).
[SANTALALES [BERBERIDOPSIDALES [CARYOPHYLLALES + ASTERIDS]]] / ASTERIDS ET AL. / SUPERASTERIDS : ?
[BERBERIDOPSIDALES [CARYOPHYLLALES + ASTERIDS]]: ?
[CARYOPHYLLALES + ASTERIDS]: seed exotestal; embryo long.
ASTERIDS / ASTERIDAE / ASTERANAE Takhtajan: nicotinic acid metabolised to its arabinosides; (iridoids +); tension wood decidedly uncommon; C enclosing A and G in bud, (connate [sometimes evident only early in development, petals then appearing to be free]); anthers dorsifixed?; if nectary +, gynoecial; G , style single, long; ovules unitegmic, integument thick, endothelium +, nucellar epidermis does not persist; exotestal [!: even when a single integument] cells lignified, esp. on anticlinal and/or inner periclinal walls; endosperm cellular.
[ERICALES [ASTERID I + ASTERID II]]: (ovules lacking parietal tissue) [tenuinucellate].
[ASTERID I + ASTERID II] / CORE ASTERIDS: ellagic acid 0, non-hydrolysable tannins not common; sugar transport in phloem active; inflorescence basically cymose; A = and opposite sepals or P, (numerous, usu. associated with increased numbers of C or G); style short[?]; duplication of the PI gene.
ASTERID II / CAMPANULIDAE: myricetin 0; vessel elements with scalariform perforation plates; endosperm copious, embryo short/very short.
[ASTERALES [ESCALLONIALES [BRUNIALES [APIALES [PARACRYPHIALES + DIPSACALES]]]]] / APIIDAE: iridoids +; C forming a distinct tube, tube initiation early; A epipetalous; ovary inferior, [2-3], style long[?].
[ESCALLONIALES [BRUNIALES [APIALES [PARACRYPHIALES + DIPSACALES]]]]: ?
[BRUNIALES [APIALES [PARACRYPHIALES + DIPSACALES]]]: ?
Age. Tank et al. (2015: Table S1) suggest that this node is around 97.4 m.y.o., while Magallón and Castillo (2009: but topology) offer estimates of ca 93.75 m.y., and ages in Beaulieu et al. (2013a) are ca 93 m.y. and in Magallón et al. (2015) ca 86.8 m. years. Note that many estimates of stem-group ages for Bruniales - implicitly the age of this node - are based on very different topologies that that used here.
Evolution. Divergence & Distribution. Diversification at this node probably occurred in the southern hemisphere (Beaulieu et al. 2013a). Bruniales are another old, species poor but morphologically quite diverse clade that is placed along the spine of the campanulids.
Phylogeny. For the relationships of Bruniales, see the asterid II clade.
BRUNIALES Dumortier Main Tree.
Plant woody, evergreen; iridoids?; nodes 1:1; flowers polysymmetric; anthers basifixed; G position?; ovules weakly crassinucellate. - 2 families, 14 genera, 79 species.
Age. Bruniales crown group age is around 110 m.y. (Bremer et al. 2004), about 93.1 m.y. (Tank et al. 2015: Table S2) or ca 78.3 m.y. (Magallón et al. 2015).
Note: Boldface denotes possible apomorphies, (....) denotes a feature common in the clade, exact status uncertain, [....] includes explanatory material. Note that the particular node to which many characters, particularly the more cryptic ones, should be assigned is unclear. This is partly because homoplasy is very common, in addition, basic information for all too many characters is very incomplete, frequently coming from taxa well embedded in the clade of interest and so making the position of any putative apomorphy uncertain. Then there are the not-so-trivial issues of how character states are delimited and ancestral states are reconstructed (see above).
Phylogeny. Within Bruniales, Bruniaceae are sister (1.0 Bayesian p.p.) to Columelliaceae in many analyses in Winkworth et al. (2008a), although not when coding chloroplast sequences were used alone, while Soltis et al. (2011) found strong support for this clade only when mitochondrial genes were removed from the analysis. 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).
Chemistry, Morphology, etc. For more on the inferior/superior ovary distinction in the campanulids, see the Asterales page.
Classification. Allthough Columellia and Desfontainea at first sight look rather different, they have a number of similarities, including some possible apomorphies, in common, and the circumscription adopted here seems reasonable.
Previous Relationships. In the first seven versions of this site (pre April 2008) Columelliaceae s.l. (= [Columelliaceae + Desfontainiaceae]) were placed immediately before the ordinal characterisation of Dipsacales - it seemed to make morphological sense and there was some other evidence for this position.
Includes Bruniaceae, Columelliaceae.
Synonymy: Columelliales Doweld, Desfontainiales Takhtajan
BRUNIACEAE Candolle, nom. cons. Back to Bruniales
Ericoid shrubs, with lignotubers; myricetin +, iridoids 0; stomata cyclocytic, with cuticular rim, orientation transverse; leaves spiral, small, close-set, lamina linear, with a black tip [phellogen], margins entire, stipules +, often minute, colleter-like (0); inflorescence racemose or spicate; flowers often small, (4-merous); K (connate), C free, often clawed, with adaxial swellings; anthers ± elongate; pollen surface variable; nectary +/0; G ± inferior, ?oblique, placentation apical-axile, style branched to the base or not, stigma capitate; ovules 2/carpel, micropyle long, integument 9-10 cells across, endothelium 0, hypostase +; K persistent in fruit; seed coat?; endosperm type?, haustoria?
6/81[list]/75. South Africa, almost entirely the Cape Province, also KwaZulu-Natal (map: from Claßen-Bockhoff 2000).
Age. Crown-group Bruniaceae are dated to 99.5-59.7 m.y.a. (Quint & Claßen-Bockhoff 2008).
There is a striking similarity between the flowers of Actinocalyx, from the Upper Cretaceous (Santonian/Campanian) ca 83.6 m.y.a. of Sweden, and those of Bruniaceae (Hall 1987).
1. Linconieae Quint & Claßen-Bockhoff
Petals hard in texture; anthers sagittate, apically connate, with sterile tip; (G ); (fruits with two seeds); n = ?
1/3. The Cape.
[Audouineae + Brunieae]: (styles also connate); fruit achenial or nut-like, seed usu. 1; x = 11, chromosomes 1.5-2.5 µm long.
2. Audouineae Niedenzu
(Stomata lacking cuticular rim); (flowers single); anther thecae parallel, connate, attached to the connective their entire length; (pollen 4-5-colpate); (G 1, ); (ovules to 8/carpel); n = 11.
2/14. Southwestern part of the Western Cape.
3. Brunieae Quint & Claßen-Bockhoff
Stomata lacking cuticular rim; inflorescence capitate, (involucrate), (with terminal flower and development centrifugal), (flowers single), etc.; anthers versatile, thecae (to rotund); (pollen 3-10-colporate); (G 1), (superior); ovules 1(-10)/carpel; fruit (with fleshy accrescent K), (dehiscent, also splitting adaxially); (seeds arillate); n = 22, 23.
3/64. Brunia (37). Esp. the Western Cape (Eastern Cape; KwaZulu-Natal [1 species]).
Synonymy: Berzeliaceae Nakai
Evolution. Divergence & Distribution. The three main clades (tribes below) had all diverged by 33.7-20.2 m.y.a., yet much of the diversification within them has occurred only within the last 18-3 m.y. (Quint & Claßen-Bockhoff 2008).
Pollination Biology & Seed Dispersal. Pollination is promiscuous. The function of the variously-shaped swellings towards the base of the adaxial surface of the petals is unclear (Claßen-Bockhoff 2016).
Myrmecochory occurs in this clade (Lengyel et al. 2010).
Chemistry, Morphology, etc. The plant is reported to be scented and the leaf apex has suberised cells produced by a localised cork cambium, hence the black tip (Carlquist 1990a).
The corolla "tube" is formed by adnation of the filaments to the two adjacent petals that are developmentally initally free (Quint & Claßen-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. There are only one or two layers of parietal cells.
Some information is taken from from Dahlgren in Dahlgren and van Wyk (1988) and Claßen-Bockhoff (2016), both general; see also Jay (1968a: chemistry), Carlquist (1978b) and Gregory (1998), both anatomy, Claßen-Bockhoff (2000: detailed discussion of inflorescences), Quint and Claßen-Bockhoff (2006b: floral ontogeny), Endress and Stumpf (1991: stamens), Hall (1988: pollen), and Saxton (1910: no endothelium shown) and Mauritzon (1939a), both embryology.
Bruniaceae are poorly known.
Phylogeny. The phylogenetic stucture [Linconieae [Audoinieae + Brunieae]] is strongly supported (Quint & Claßen-Bockhoff 2006a).
Classification. Claßen-Bockhoff et al. (2011) propose a tribal classification based on the phylogeny by Quint and Claßen-Bockhoff (2006a). 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 are ericoid shrubs growing in similar habitats.
Thanks. To Regine Claßen-Bockhoff for useful comments.
COLUMELLIACEAE D. Don, nom. cons. Back to Bruniales
Cork cambium deep-seated; pericyclic fibres 0; petiole bundles arcuate; bud without scales; leaves opposite, petiole bases meeting, lamina margins toothed; inflorescence terminal, cymose; flowers medium-sized; anther connective well-developed, thecae attached their entire length; ovules many/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.
Age. These two genera diverged around 64 m.y.a. (Bremer et al. 2004).
1. Columellia D. Don
Shrubs or trees; plant bitter tasting, ?chemistry; styloids +; central petiole bundle much the largest; cuticle waxes as tubules; lamina (with glands on lower surface), teeth glandular (0); flowers (4-8-merous); K ± valvate; A 2, latrorse, thecae semicircular, connective broad, expanded; tapetum amoeboid; G largely inferior, placentation intrusive parietal or lobed-axile, stigma with two broad lobes, almost cup-like; ovules ?lacking parietal tissue; fruit septicidal and part loculicidal, opening down the sides; exotestal cells elongated; endosperm type?; n = ?
1/4. S. Colombia to Bolivia, in the Andes (map: from Brizicky 1961). [Photo - Flower.]
2. Desfontainia Ruíz & Pavón
Shrubs; route I secoiridoids +, tannin 0; scattered sclereids in the pericyclic position; lamina vernation conduplicate, teeth spiny, colleters +; inflorescence usu. single-flowered; K connate at base, C contorted; A adnate in throat, filaments stout; G [5(-7)], opposite petals, placentation axile but apically parietal, stigma only slightly expanded; ovule with integument 6-9 cells across; 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.]
Symonymy: Desfontainiaceae Pfeiffer
Evolution. Divergence & Distribution. Another old, species-poor but morphologically quite diverse group that is restricted to 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 also 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 general information, see Backlund (2016). For Columellia, see Hasselberg (1937: growth), 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, see 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). Desfontainea has usually been included in the heterogeneous Loganiaceae - and so it was not associated with Columellia.