Muelleranthus

Taxonomy

Muelleranthus J. Hutchinson Gen. Fl. Pl. 361. 1964.

Subfamily: Faboideae.
Phylogenetic Number: 3.23.08.
Tribe: Bossiaeeae.
Group: Bossiaea.
Species Studied - Species in Genus: 2 studied; 3 in genus.

Description

Fruit: A legume; unilocular; (13–)17–25(–29) cm long; 0.4–0.5(–0.6) cm wide; 0.12–0.2 cm thick; 2–9 times longer than wide; with deciduous androecial sheath; with deciduous corolla; with deciduous calyx; without orifice formed by curving of fruit or fruit segments; straight; not plicate; not twisted; asymmetrical, or symmetrical; linear; with both sutures nearly straight; not inflated; flattened; without beak; short tapered at apex; aligned with longitudinal axis of fruit; short tapered at base; aligned with longitudinal axis of fruit; with the apex and base uniform in texture; coriaceous; seed chambers externally visible; seed chambers with the raised seed chambers not torulose; margin not constricted; margin without sulcus; margin plain; wing(s) absent; substipitate; with all layers dehiscing; splitting along suture(s). Dehiscence of valves along both sutures; apical and down; passive. Replum invisible. Epicarp dull; monochrome; reddish brown; with surface texture uniform; glabrous; 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; thin; surface not veined; 1-layered; without balsamic vesicles; without fibers; without reniform canals; solid; coriaceous. Endocarp present; visible; dull; opaque; monochrome; tan; smooth; without adhering pieces of testa; nonseptate; chartaceous; not exfoliating; remaining fused to mesocarp and epicarp; without wings; entire. Seed(s) 6–10; length parallel with fruit length (because seeds are round, both length or width can be considered parallel to fruit length); neither overlapping nor touching; in 1 series. Funiculus of 1 length only; thick; curved. Aril present; dry; when dry rim-aril; entire; white.

Seed: 2–2.2 mm long; 2–2.2 mm wide; 1.5 mm thick; not overgrown; not angular; symmetrical; circular; terete; 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; mottled and streaked, or monochrome (when immature); with frequent mottles; with frequent streaks; tan; with orange overlay, yellow overlay, brown overlay, and red overlay (the orange overlay forming a reticulate pattern from hilum to base, the brown overlay reddish, and the red overlay with a brick tone), or black overlay (when fully mature (Lee, 1973)); glabrous; smooth; coriaceous. Pleurogram absent. Pseudopleurogram absent. Fracture lines absent. Rim 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; punctiform; marginal according to radicle tip; recessed; within rim; rim color darker than testa. Lens discernible; not in groove of raphe; adjacent to hilum; 0.2 mm from hilum; mounded; dissimilar color from testa; darker than testa; black (ish); within rim; rim color darker than testa. Endosperm present; thin; not pluglike and not resembling tip of radicle; covering entire embryo; adnate to testa. 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; entire over radicle; without lobes; with the interface division terminating at base of radicle; without margins recessed; yellow; 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; deflexed and parallel to cotyledon length; centered between cotyledons; less than 1/2 length of cotyledons. Plumule moderately developed; glabrous.

Distribution

Australia.

Old World; Australia.

Generic Notes

Lee (1973) noted that M. trifoliatus (F.J.H. von Mueller) J. Hutchinson ex A.T. Lee has at first a "reduced hooded aril as in Aenictophyton" (23.10) and "finally not arillate." She also noted that M. stipularis seeds are not arillate. Based on our observations the seeds of both species of Muelleranthus and the one species of Aenictophyton have a dry rim aril. Perhaps Lee thought the curved funiculus was a "hooded aril" that disappeared on maturation. Fruits and seeds of M. crenulatus A.T. Lee are unknown. The attractive seeds of M. stipularis and M. trifoliatus resemble a stained glass window. Similar colors may be found in seeds of some species of Vicia (19.01)

Tribal Notes

Tribe Bossiaeeae

The Bossiaeeae with ten genera traditionally has been divided into two groups in part on fruit and seed characters. The Templetonia group with the first four genera (including at the time Lamprolobium, 23.02) has non-winged, coriaceous legumes and compressed seeds bearing a collarlike often-lipped aril (except Templetonia biloba (G. Bentham) R.M. Polhill), and a short, straight radicle. The Bossiaea group with the remaining genera has the legumes keeled to winged or not so, plump seeds often covered by a hooded caplike aril (lacking in Muelleranthus (23.08) and Ptychosema (23.09)), and a slender deflexed radicle exserted from the cotyledons. Crisp and Weston (1987, pages 105–107) in their cladistic analysis of the Bossiaeeae, Brongniartieae (22), and Mirbelieae (24), provided compelling evidence that the Bossiaeeae should be redefined to include only the Bossiaea group (genera 23.05–23.10). The Templetonia group would be moved to the Brongniartieae becoming genera three through eight, after Brongniarta (22.01) and Harpalyce (22.02). The proposed generic sequence would be: 3, Templetonia (23.01); 4, Lamprolobium; 5, Plagiocarpus (23.03); 6, ?Genus A (Templetonia incana J.H. Ross); 7, ?Genus B (Templetonia biloba (G. Bentham) R.M. Polhill); and 8, Hovea (23.04). They (Crisp and Weston, 1995) retracted their proposal to transfer the Templetonia group because of Chappill's (1995) cladistic analysis of the entire family, and we have used the traditional circumscriptions of the two tribes (Pohill, 1994a, 1994b).