Subfamily: Caesalpinioideae.
Phylogenetic Number: 1.4.36.
Tribe: Detarieae.
Group: Crudia.
Species Studied - Species in Genus: 1 studied; 1 in genus.
Fruit: A legume; unilocular; 3.5–6 cm long; 2–3.2 cm wide; 0.3–0.4 cm thick; length less than twice as long as width; with deciduous androecial sheath; with deciduous corolla; with deciduous calyx; without orifice formed by curving of fruit or fruit segments; curved; not plicate; not twisted; symmetrical, or asymmetrical; C-shaped, or reniform; with both sutures parallelly curved, or both sutures unequally curved; not inflated; flattened; without beak; tapered at apex; stated as "marginal apex"; short tapered at base; aligned with longitudinal axis of fruit; with the apex and base uniform in texture; coriaceous; seed chambers externally invisible; margin not constricted; margin without sulcus; margin plain; wing(s) absent; stipitate to substipitate; with the stipe 6 mm long; tardily with all layers dehiscing to indehiscent; splitting along suture(s). Dehiscence of valves along 1 suture (folliclelike); passive. Replum invisible. Epicarp dull; monochrome; tan; with surface texture uniform; glabrous; eglandular; without spines; not smooth; with elevated features; veined; reticulately veined; not tuberculate; not exfoliating; without cracks; without embedded tissue, much thicker than epicarp, running from base to apex. Mesocarp present; surface not veined; 1-layered; without balsamic vesicles; with fibers; without reniform canals; reticulate fibrous throughout; coriaceous. Endocarp present; visible; dull to glossy; opaque; monochrome; reddish brown to tan; without adhering pieces of testa; nonseptate; not exfoliating; remaining fused to mesocarp and epicarp; entire. Seed(s) 1; length parallel with fruit length, or transverse to fruit length (parallel according to seed length but transverse according to embryonic axis). Funiculus 0.1–1 mm long; of 1 length only; filiform; straight. Aril absent.
Seed: 18–30 mm long; 10–15 mm wide; 2–4 mm thick; not overgrown; not angular; asymmetrical; reniform; flattened; with surface smooth; without visible radicle and cotyledon lobes; without hilar sinus; without umbo on seed faces; without medial ridge on each face. Cuticle not exfoliating; not inflated; not wrinkled. Testa present; without pieces of adhering epicarp; not adhering to endocarp; free from endocarp; dull; not modified by a bloom; colored; bichrome; reddish brown and tan (interstices and margins); glabrous; not smooth; with elevated features and recessed features; wrinkled; punctate (dotted with numberous large odoriferous reddish resinous glands and if ruptured, the area around glands glossy); chartaceous. Pleurogram absent. Pseudopleurogram absent. Fracture lines absent. Rim absent. Wing(s) absent. Raphe not visible. Hilum present; fully concealed; concealed by funicular remnant; without faboid split; punctiform; apical according to radicle tip but marginal according to seed length (?); recessed; not within corona, halo, or rim. Lens not discernible. Endosperm absent. Cotyledons not smooth; ruminate; both outer faces convex; both the same thickness; both more or less of equal length; not folded; margin not entire 180 degrees from base of radicle (wavy); similar at apex; partially concealing radicle (only tip exposed); notched at radicle (and lobes); with lobes; with lobes touching (auriculate); without basal groin formed by lobes; with the interface division terminating at base of radicle; without margins recessed; inner face flat; glabrous on inner face. Embryonic axis straight; perpendicular to length of seed; without a joint evident between the radicle and the cotyledons. Radicle differentiated from cotyledon; centered between cotyledons. Plumule rudimentary; glabrous.
Breteler et al. (1997) proposed synonymizing Colophospermum and Hardwickia (1.4.34). The united genus would have the name Hardwickia, the older generic name, and two species, H. mopane (T. Kirk ex G. Bentham) F.J. Breteler [C. mopane (T. Kirk ex G. Bentham) T. Kirk ex J.J.G. Léonard] from southern Africa and H. binata W. Roxburgh from southern India. They stressed the overwhelming similarity of the two genera with very few differences separating them. Our seed data contradicts their conclusion. We found that the two genera were separated by the following fruit and seed characters: Hardwickia--fruit 1–1.8 cm wide, 2–9 times longer than wide, straight, outline symmetrical, long tapered at apex, tapered at base, seed chambers visible; fruit wing present; epicarp longitudinally veined relative to fruit length; mesocarp without fibers, solid; funiculus thick; seed symmetrical, oblong; testa monochrome, osseous; hilum flush; cotyledons 1–3 grooved on each face, margin entire 180 degrees from base of radicle, with lobes not touching; embryonic axis parallel to length of seed; and Colophospermum--fruit 2–3.2 cm wide, length less than twice as long as width, curved, asymmetrical, tapered at apex, short tapered at base, seed chambers invisible; fruit wing absent; epicarp reticulately veined; mesocarp with fibers present, fibrous throughout; funiculus filiform; seed asymmetrical, reniform; testa bichrome, chartaceous; hilum recessed; cotyledons ruminate, margin not entire 180 degrees from base of radicle, with lobes touching (auriculate); embryonic axis perpendicular to length of seed. Léonard (1999) presented a rebuttal to Breteler et al. (1997) in favor of maintinaing the two genera. In addition to fruit and seed characteristics, he also stressed differences in number of sepals, corolla aestivation, number of stamens, presence or absence of a floral disk, anther texture, and position of style attachment. We have chosen to keep the genera separate. Timberlake (1999) has also maintained the genus Colophospermum.
Jordaan and Wessels (1999) and Jordaan et al. (2001) have interpreted the seed coat differently than we do. They carried out anatomical studies of Colophospermum seeds. They described the seeds as 'overgown' with thin seed coats lacking the anatomical structures of typical faboid seeds. The structure surrounding the seeds, they interpreted as an out growth of the seed coat, which they called an aril.
Smith et al. (1998) proposed conserving the name Colophospermum against Hardwickia, which would change the name of the united genus to Colophospermum thereby maintaining C. mopane. The IAPT Committee for Spermatophyta was evenly divided on conservation of Colophospermum and did not recommend it for conservation (Brummitt, 2000), so the proposal will be formally rejected at the next International Botanical Congress.
Authors: J.H. Kirkbride, Jr., C.R. Gunn, A.L. Weitzman, M.J. Dallwitz, K.R. Thiele
Content last updated April 2003
Released April 2024 on idtools.org
