Gastrolobium

Taxonomy

Gastrolobium R. Brown In W. T. Aiton, Hortus Kew. ed. 2. 3: 16. Oct-Nov 1811.

Subfamily: Faboideae.
Phylogenetic Number: 3.24.13.
Tribe: Mirbelieae.
Group: Oxylobium.
Species Studied - Species in Genus: 22 studied; 109 in genus.

Description

Fruit: A legume; unilocular; 0.5–2 cm long; 0.2–1(–3.5) cm wide; 0.2–0.65 cm thick; length less than twice as long as width, or 2–9 times longer than wide, or wider than long; with deciduous androecial sheath, or persistent androecial sheath (with the standard, former Brachysema); with deciduous corolla, or persistent corolla (with the androecial sheath, foermer Brachysema); with various petals; with persistent calyx; with calyx shorter than fruit, or equal in length to fruit (sub); without orifice formed by curving of fruit or fruit segments; straight; not plicate; not twisted; symmetrical, or asymmetrical; ovate, or circular, or oblong, or elliptic; with 1 straight and 1 curved suture, or both sutures unequally curved (Nemcia), or both sutures parallelly curved (Nemcia); widest near middle or D-shaped; not inflated; terete; without beak, or with beak (Nemcia); straight, or declined; with solid beak the same color and texture as fruit; rounded at apex, or tapered at apex to short tapered at apex; aligned with longitudinal axis of fruit; short tapered at base, or rounded at base, or tapered at base; aligned with longitudinal axis of fruit, or oblique with longitudinal axis of fruit; with the apex and base uniform in texture; coriaceous, or ligneous; seed chambers externally invisible; margin not constricted; margin without sulcus; margin plain; wing(s) absent; stipitate, or substipitate, or nonstipitate; with the stipe 0.1–9 mm long; with all layers dehiscing; splitting along suture(s). Dehiscence of valves along both sutures; apical and down (at least 1/2 way in Nemcia); passive. Replum invisible. Epicarp dull; monochrome, or multicolored; mottled; dark to light reddish brown, or tan, or red (rarely); with purple overlay; with surface texture uniform; glabrous, or pubescent and indurate, or glabrate; with hairs erect, or appressed; with 1 type of pubescence; villous, or sericeous (Brachysema), or tomentose (Brachysema); with pubescence gray, or brown, or golden; with pubescence uniformly distributed; with simple hairs; pliable; with hair bases plain; eglandular; without spines; not smooth; with elevated features; veined; reticulately veined, or transversely veined relative to fruit length (Brachysema); not tuberculate; wrinkled (Brachysema); not exfoliating, or exfoliating in part (Brachysema); without cracks, or with cracks (Brachysema); cracking transverse to fruit length (Brachysema); without embedded tissue, much thicker than epicarp, running from base to apex. Mesocarp present; thin, or thick (Brachysema); surface not veined; 1-layered; without balsamic vesicles; without fibers; without reniform canals; solid; coriaceous, or ligneous (Brachysema). Endocarp present; visible; dull, or glossy (Nemcia); opaque; monochrome; reddish or pale tan to tan; smooth, or scurfy, or reticulate (Nemcia), or smooth and cracked (transversely, Brachysema); without adhering pieces of testa; nonseptate; chartaceous, or ligneous (Brachysema); not exfoliating; remaining fused to mesocarp and epicarp; without wings; entire. Seed(s) 1–7; length parallel with fruit length, or transverse to fruit length (Brachysema); overlapping and touching (Brachysema); in 1 series (Brachysema). Funiculus 0.5–2 mm long; of 1 length only (Brachysema); thick, or filiform (Brachysema); straight, or curved (near apex). Aril present, or absent; fleshy (to somewhat dry, but better developed than rim-aril), or dry (Nemcia); when fleshy topknotlike, or marginal hilar, or cupshaped (Brachysema); entire, or crenate (Brachysema); covering 1/2 to nearly all of seed, or less than 1/2 of seed (Brachysema and Nemcia); when dry rim-aril (Nemcia); entire; reddish tan, or cream, or brown (reddish, Brachysema and Nemcia).

Seed: 1–5 mm long; 1.3–3 mm wide; 1–2.3 mm thick; not overgrown; angular, or not angular; asymmetrical, or symmetrical; mitaform, or oblong, or reniform to elliptic, or circular, or D-shaped; compressed; with surface smooth; with visible radicle and cotyledon lobes, or without visible radicle and cotyledon lobes; without external groove between 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; glossy, or dull (Brachysema); not modified by a bloom; colored; monochrome, or mottled, or mottled and streaked; with frequent mottles; reddish brown, or black; with purple overlay, or brown overlay (Nemcia); glabrous; smooth, or not smooth (rarely); with elevated features; transversely ridged; coriaceous. Pleurogram absent. Pseudopleurogram absent. Fracture lines absent. Rim absent. Wing(s) absent. Raphe not visible. Hilum present; partially concealed; concealed by aril; with faboid split; with the lips of the faboid split the same color as the rest of the hilum; larger than punctiform; 0.7–1 mm long; with curved outline, or straight outline (Nemcia); oval, or circular (Brachysema); oblong (Nemcia); marginal according to radicle tip, or between cotyledon and radicle lobe (Brachysema); recessed; within rim, or not within corona, halo, or rim (Brachysema and Nemcia), or within halo (Brachysema); halo nearly of testa (Brachysema); rim color darker than testa. Lens discernible, or not discernible (Brachysema); 0.1–1 mm long; with margins straight, or curved; oblong; circular, or oblong, or key-hole shaped (Brachysema); not in groove of raphe; confluent with hilum, or adjacent to hilum; 0.1–0.2 mm from hilum; mounded, or flush; similar color as testa, or dissimilar color from testa (Brachysema and Nemcia); darker than testa; dark reddish brown or brown, or black (Nemcia); not within corona, halo, or rim. Endosperm present; thin, or thick (Brachysema); not pluglike and not resembling tip of radicle; covering entire embryo; adnate to testa, or embryo (Brachysema and Nemcia). Cotyledons smooth; both outer faces convex; both the same thickness; both more or less of equal length; not folded; margin entire 180 degrees from base of radicle; similar at apex; not concealing radicle; split over radicle, or entire over radicle (Brachysema and Nemcia); with lobes, or without lobes (Brachysema and Nemcia); with the interface division terminating at base of radicle; without margins recessed; reddish tan to tan, or brown (reddish), or yellow (Brachysema); inner face flat; glabrous on inner face. Embryonic axis deflexed; oblique to length of seed; without a joint evident between the radicle and the cotyledons. Radicle differentiated from cotyledon; linear, or bulbose (Brachysema and Nemcia); lobe tip straight (Brachysema); deflexed and parallel to cotyledon length; centered between cotyledons; less than 1/2 length of cotyledons. Plumule rudimentary, or moderately developed (Brachysema); glabrous.

Distribution

Generic Notes

Crisp and Weston (1987) included the Oxylobium parviflorum J. Lindley group in Gastrolobium. Chandler et al. (2001) constructed a molecular phylogeny of Gastrolobium and related genera, including Brachysema (3.24.16), Jansonia (3.24.17), Nemcia (3.24.15), and Oxylobium (3.24.09). Their conclusions were that Gastrolobium is paraphyletic and that Brachysema, Jansonia, Nemcia, and Oxylobium lineare (G. Bentham) G. Bentham should probably be included in it. Chandler et al. (2002) monographed Gastrolobium implementing the conclusions of the molecular phylogeny. They included Brachysema, Jansonia, Nemcia, and Oxylobium lineare in Gastrolobium, providing new combinations when necessary, and described 29 new species in the genus. Their species count was been used.

Tribal Notes

Tribe Mirbelieae

Crisp and Weston (1987) analyzed the Mirbelieae, and we are following their species counts. We did not treat the following new taxa of Crisp and Weston: the Pultenaea incurvata A. Cunningham group of five species; Pultenaea neurocalyx P.K.N.S. Turczanivow, a one species group; Aotus phyliocides G. Bentham, a one species group; and, Oxylobium microphyllum G. Bentham, a two species genus. The genus Cupulanthus J. Hutchinson is listed on page 85 of Crisp and Weston (1987) and not mentioned by them again. Crisp and Weston (1995) have continued their phylogenetic studies of Mirbelieae, and proposed two major generic changes, the resurrection of Podolobium R. Brown with six species of Oxylobium (24.09, see Notes for Oxylobium) and a new genus, tentatively to be named Otion. Otion, as projected, will have six species, two new ones and four from four different genera: Aotus phylicoides G. Bentham, Burtonia simplicifolia F.J.H. von Mueller & R. Tate, Oxylobium microphyllum G. Bentham, and Phyllota luehmannii F.J.H. von Mueller.