Dalea

Taxonomy

Dalea C. Linnaeus Nom. cons. Opera Varia 244. 1758.

Subfamily: Faboideae.
Phylogenetic Number: 3.6.08.
Tribe: Amorpheae.
Species Studied - Species in Genus: ca. 60 studied; ca. 160 in genus.

Description

Fruit: A legume; unilocular; 0.2–0.6 cm long; 0.17–0.21 cm wide; 0.09–0.15 cm thick; length less than twice as long as width; with persistent androecial sheath (with keel and standard), or deciduous androecial sheath; with persistent corolla (with androecial sheath), or deciduous corolla; with keel petal and standard petal; with persistent calyx (with or without prominent glandular dots between ribs); with calyx longer than fruit to equal in length to fruit to shorter than fruit; without orifice formed by curving of fruit or fruit segments; straight to curved (slightly); not plicate; not twisted; asymmetrical; C-shaped, or circular (subcircular and), or obovate, or triangular, or harp-shaped; with 1 straight and 1 curved suture, or both sutures parallelly curved, or both sutures unequally curved; widest near middle or D-shaped; not inflated (except fragile base may be slightly larger than seed); compressed to terete; without beak, or with beak; straight; with solid beak the same color and texture as fruit; rounded at apex; oblique with longitudinal axis of fruit; short tapered at base; oblique with longitudinal axis of fruit; with the apex and base uniform in texture, or differing in texture; upper 1/4–2/3 firm and/or pubescent and lower 3/4–1/3 fragile and glabrous; membranous to chartaceous; seed chambers externally visible; seed chambers with the raised seed chambers not torulose; margin not constricted; margin without sulcus; margin plain; wing(s) absent; nonstipitate; often indehiscent, or with all layers dehiscing (occasionally in species such as D. leporina (W. Aiton) A.A. Bullock and D. urceolota E.L. Greene); splitting along suture(s). Dehiscence of valves along both sutures; passive. Replum invisible. Epicarp dull; multicolored; bichrome (and additionally large reddish-brown glands); brown (apically brown, basally tan); with surface texture uniform; glabrous, or pubescent and indurate; with hairs erect; with 1 type of pubescence; pilose, or villous; with pubescence red (-brown), or gray; with pubescence uniformly distributed; with simple hairs; pliable; with hair bases plain; glandular, or eglandular; with glandular dots (arranged in crescents or random and either faint or prominent and large or tiny (microglandular in Barneby, 1977)); limited to a portion of fruit; upper 1/4 glandular and lower 3/4 eglandular, or 1/2 glandular and lower 1/2 eglandular, or 2/3 glandular and lower 1/3 eglandular; without spines; not smooth; with elevated features; veined, or not veined; reticulately veined; not tuberculate; occasionally warty, or wrinkled (occasionally); not exfoliating; without cracks; without embedded tissue, much thicker than epicarp, running from base to apex. Mesocarp absent. Endocarp present; visible; dull; opaque; monochrome; tan; smooth; without adhering pieces of testa; nonseptate; chartaceous; not exfoliating; remaining fused to epicarp; without wings; entire. Seed(s) 1 (mostly); length parallel with fruit length; neither overlapping nor touching; in 1 series. Funiculus of 1 length only; filiform; straight. Aril absent.

Seed: 1–4.2 mm long; 1.2–2.6 mm wide; 0.5–1.4 mm thick; not overgrown; not angular; asymmetrical; elliptic (oblong), or mitaform, or reniform; compressed; with 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; not modified by a bloom; colored; monochrome; brown (reddish to pale or), or green, or olive, or tan; glabrous; smooth; coriaceous. Pleurogram absent. Pseudopleurogram absent. Fracture lines absent. Rim absent. Wing(s) absent. Raphe not visible. Hilum present; visible; with faboid split; with the lips of the faboid split the same color as the rest of the hilum; punctiform; between cotyledon and radicle lobe; recessed; within rim; rim color lighter than testa. Lens discernible, or not discernible; 0.3–0.5 mm long; with margins straight, or curved; linear, or triangular, or wedge-shaped; circular; not in groove of raphe; adjacent to hilum (and penetrating hilum rim); mounded; same color as testa, or similar color as testa, or dissimilar color from testa; lighter than testa, or darker than testa; black, or tan; within rim (penetrating rim), or not within corona, halo, or rim. Endosperm present; thin; not pluglike and not resembling tip of radicle; covering entire embryo; adnate to testa, or embryo. 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; partially concealing radicle; split over radicle; with lobes; with lobes not touching; with the interface division terminating at base of radicle; without margins recessed; tan; inner face flat; glabrous on inner face. Embryonic axis deflexed, or oblique; oblique to length of seed; without a joint evident between the radicle and the cotyledons. Radicle differentiated from cotyledon; bulbose, or linear; lobe tip straight, or curved; deflexed and parallel to cotyledon width; centered between cotyledons; less than 1/2 length of cotyledons, or 1/2 to nearly length of cotyledons. Plumule rudimentary; glabrous.

Distribution

Canada to Argentina.

New World; Canada to United States to West Indies to Mexico to Central America to South America (to Argentina); Argentina, Peru, and the Guianas.

Generic Notes

Barneby (1977) monographed Dalea (including Parosela sensu P.A. Rydberg, Petalostemum C.L. Michaux, and Kuhistera J.B.A.P. de M. de Lamarck, but excluding Marina F.M. Liebmann). Barneby also provided literate descriptions of the interesting and varied external topography of the fruit. The species count follows Barneby (1981). Although it appears that fruits of most species of Dalea do not have a regular dehiscence mechanism, the lower half is fragile and ruptures irregularly allowing the seed to fall out easily.

Tribal Notes

Tribe Amorpheae

Traditionally this tribe has been called Amorpheae. Reveal (1997) reported that the name Daleeae was published before the name Amorpheae. Following the International Code of Botanical Nomenclature (Greuter et al., 1994), the oldest name for a taxon must be used, so Reveal suggested that this tribe should called Daleeae. In 1999 Reveal (1999) reversed himself, so that the tribe remains the Amorpheae.