Dahlstedtia

Taxonomy

Dahlstedtia G.O.A. Malme Ark. Bot. 4(9): 4. 14 Apr 1905.

Subfamily: Faboideae.
Phylogenetic Number: 3.7.
Tribe: Millettieae.
Species Studied - Species in Genus: 1 studied; 1 in genus.

Description

Fruit: A legume; unilocular; 7–16 cm long; 2.5–5 cm wide; 1–3 cm thick (assumed); 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; irregular; with both sutures unequally curved; not inflated, or inflated (slightly, in literature); compressed; without beak; blunt at apex to short tapered at apex; aligned with longitudinal axis of fruit to oblique with longitudinal axis of fruit; tapered at base to short tapered at base; aligned with longitudinal axis of fruit to oblique with longitudinal axis of fruit; with the apex and base uniform in texture; chartaceous to coriaceous; seed chambers externally visible; seed chambers with the raised seed chambers not torulose; margin not constricted, or constricted; margin slightly constricted along both margins; margin without sulcus; margin plain; wing(s) absent; substipitate; indehiscent (from literature). Replum invisible. Epicarp dull; monochrome, or multicolored; mottled; brown; with darker brown overlay; mottling color combination variable; with surface texture uniform; glabrous; eglandular; without spines; not smooth; with elevated features; veined; reticulately veined to irregularly veined; not tuberculate; wrinkled; not exfoliating; without cracks; without embedded tissue, much thicker than epicarp, running from base to apex. Seed(s) 1–4 (from literature); length parallel with fruit length, or oblique to fruit length; neither overlapping nor touching; in 1 series.

Seed: 30–35 mm long; 20–25 mm wide; 15–20 mm thick; not overgrown; not angular; asymmetrical; obliquely reniform; compressed. Testa present. Hilum present; larger than punctiform; with curved outline; circular.

Distribution

Southern Brazil.

New World; South America (Brazil).

Generic Notes

Only one immature fruit was available for study. Other information was derived from photocopies of herbarium specimens and literature (Geesink 1984).

Tribal Notes

Tribe Millettieae

Geesink (1981) treated this tribe, as others before him, under the tribal name Tephroseae, but we now know that its correct name is Millettieae. Recent tribal studies (Geesink, 1981, 1984; Polhill, 1994a, 1994b) have arranged the genera in alphabetical order without phylogenetic numbers. Geesink (1984) monographed tribe Millettieae, and presented descriptive notes about fruits and seeds and in situ fruit and seed drawings. However, we are not entirely following Geesink (1984) for generic parameters because he either questioned the status of many of his new genera or did not make the necessary species transfers. The few new genera which he clearly recognized are being accepted. Lavin et al. (1998) developed a preliminary infratribal classification of six informal groups using phytochrome nucleotides: Millettia group, Lonchocarpus group, Derris group, Tephrosia group, "primitive" group, and Phaseoleae group. Lavin (1987) transferred Sphinctospermum to Millettieae. Lavin and Doyle (1991) carried out cladistic analyses integrating morphological and chloroplast DNA data, and concluded that it is a member of Robineae where we have placed it (now 8.12).