Sesbania

Taxonomy

Sesbania G.A. Scopoli Nom. cons. Introd. 308. Jan-Apr 1777.

Subfamily: Faboideae.
Phylogenetic Number: 3.8.01.
Tribe: Robinieae.
Group: Sesbania.
Species Studied - Species in Genus: 38 studied; ca. 50 in genus.

Description

Fruit: A legumelegume:
usually dry, dehiscent fruit derived from a single carpel that opens along two longitudinal sutures
; unilocular; 2–30 cm long; 0.2–1.8 cm wide; 0.2–0.9 cm thick; more than 9 times longer than wide, or 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, or curved (or slightly curved); not plicate; not twisted, or twisted; symmetrical, or asymmetrical (rarely in Sesbania sect. Glottidium); linear, or oblong, or elliptic; with both sutures parallelly curved (in Sesbania sect. Glottidium); not inflated; terete, or compressed; with beak, or without beak; straight; with solid beak the same color and texture as fruit; tapered at apex, or short tapered at apex; aligned with longitudinal axis of fruit; truncate at base, or short tapered at base, or long tapered at base (in Sesbania sect. Glottidium); aligned with longitudinal axis of fruit (slightly), or oblique with longitudinal axis of fruit; with the apex and base uniform in texture; ligneous, or coriaceous (with thicken sutures), or membranous (in Sesbania sect. Glottidium); seed chambers externally visible; seed chambers with the raised seed chambers torulose; margin not constricted, or constricted; margin slightly constricted along both margins, or constricted along both margins; margin without sulcus; margin plain, or embellished; margin with wing(s); wing(s) absent, or present; wing(s) 4; wing(s) 0.1–10 mm wide; wing(s) continuous wing around fruit; stipitate, or nonstipitate; with the stipe 5–15 mm long; with all layers dehiscing (to subdehiscent), or with epicarp and mesocarp dehiscing and endocarp not dehiscing (in Sesbania sect. Glottidium); splitting along suture(s), or with epicarp and mesocarp splitting along suture, endocarp entire, forming an envelope around the seeds with flat winglike areas (in Sesbania sect. Glottidium). Dehiscence of valves along both sutures; medial and up and down, or apical and down; passive. Replum invisible. Epicarp dull; monochrome, or multicolored; mottled; brown (to reddish), or tan; with red overlay; with surface texture uniform; glabrous; eglandular, or glandular; with glandular dots; without spines; not smooth; with elevated features; veined; reticulately veined; not tuberculate; wrinkled, or warty (somewhat and tiny, in Sesbania sect. Glottidium); not exfoliating, or exfoliating in part, or exfoliating; without cracks; without embedded tissue, much thicker than epicarp, running from base to apex. Mesocarp present; thick, or trace, or thin (in Sesbania sect. Glottidium); surface not veined; 1-layered; without balsamic vesicles; without fibers; without reniform canals; solid, or vitriol (individual "pellets"); coriaceous, or ligneous (sub), or chartaceous (in Sesbania sect. Glottidium). Endocarp present; visible; glossy, or dull (in Sesbania sect. Glottidium); opaque; monochrome; tan (pale); smooth; without adhering pieces of testa; septate, or nonseptate (in Sesbania sect. Glottidium); with septa thicker than paper, firm and thin (tissue paper-like), flexible, or thin (tissue paper-like), flexible; with septa eglandular; coriaceous; not exfoliating; remaining fused to mesocarp and epicarp, or separating from mesocarp (as 1- or 2-seeded winged indehiscent unit, in Sesbania sect. Glottidium); without wings, or with wing(s) extending into epicarp, or with wing(s) not extending into epicarp (inSesbania sect. Glottidium); entire. Seed(s) 5–40, or (1–)2 (in Sesbania sect. Glottidium); length parallel with fruit length; neither overlapping nor touching; in 1 series. Funiculus virtually no length; of 1 length only; flattened, or filiform (in Sesbania sect. Glottidium); straight. Aril absent, or present; dry; when dry rim-aril; entire; brown, or white.

Seed: 3–7 mm long, or 10–12 mm long (in Sesbania sect. Glottidium); 1.5–5 mm wide, or 4.5–6.5 mm wide (in Sesbania sect. Glottidium); 1.5–5 mm thick; not overgrown; not angular; asymmetrical; oblong, or rectangular, or quadrangular, or mitaform, or reniform; terete, or compressed; with surface smooth; without visible radicle and cotyledon lobes, or with visible radicle and cotyledon lobes (in Sesbania sect. Glottidium); 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, or partially adhering to endocarp (thin scurfy layer); free from endocarp; glossy, or dull; not modified by a bloom; colored; monochrome, or mottled and streaked, or bichrome; with frequent mottles; with frequent streaks; brown (to reddish or greenish), or tan, or green, or olive, or blue (gray), or gray (blue), or orange; with brown overlay (reddish), or purple overlay, or black overlay; glabrous; smooth; coriaceous, or osseous (in Sesbania sect. Glottidium). Pleurogram absent. Pseudopleurogram absent. Fracture lines absent, or present; reticulate. Rim absent. Wing(s) absent. Raphe not visible, or visible (what appears to be a raphe is scored as the lens); from lens to base of seed and bifurcating; not bifurcating; darker than testa; brown (reddish); flush. Hilum present; visible, or fully concealed (nearly), or partially concealed; concealed by aril (rim), or funicular remnant (in Sesbania sect. Glottidium); with faboid split; with the lips of the faboid split the same color as the rest of the hilum, or lighter colored than the rest of the hilum and therefore conspicuous; punctiform, or larger than punctiform; 0.3–1.5 mm long, or 5 mm long (in Sesbania sect. Glottidium); with curved outline, or straight outline (in Sesbania sect. Glottidium); circular; marginal according to radicle tip; flush (slightly), or recessed (in Sesbania sect. Glottidium); within rim, or not within corona, halo, or rim; rim color lighter than testa, or darker than testa (slightly), or of testa (in Sesbania sect. GlottidiumI). Lens discernible; 0.5–1.2 mm long, or 2.5 mm long (in Sesbania sect. Glottidium); with margins straight, or curved; linear (more or less within darker circle), or oblong (in Sesbania sect. Glottidium); circular (more or less with central line or groove), or elliptic, or oblong (in Sesbania sect. Glottidium); not in groove of raphe; confluent with hilum, or adjacent to hilum; 0.1–1.5 mm from hilum; mounded (slight to well developed); similar color as testa; darker than testa; brown (reddish), or black; not within corona, halo, or rim. Endosperm present; thick, or thin (in Sesbania sect. Glottidium); not pluglike and not resembling tip of radicle; covering entire embryo; adnate to thick layer embryo and testa (thin layer). 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; with lobes; without basal groin formed by lobes, or with basal groin formed by lobes (in Sesbania sect. Glottidium); with the interface division terminating at base of radicle; without margins recessed; tan, or yellow (pale), or white; 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; bulbose; lobe tip straight (in Sesbania sect. Glottidium); deflexed and parallel to cotyledon length, or deflexed and parallel to cotyledon width; centered between cotyledons; less than 1/2 length of cotyledons. Plumule rudimentary, or moderately developed; glabrous.

Distribution

Pansubtropical and pantropical and Sesbania sect. Glottidium in southeastern United States.

New World, or Old World; pan warm temperate to pansubtropical to pantropical; United States to West Indies to Mexico to Central America to South America; Argentina, Peru, Brazil, Ecuador, and the Guianas; Africa to Madagascar to Southwest Asia to India to Indochina to China to Australia to Indonesia and the Philippines to Fiji to Hawaii to Macaronesia.

Generic Notes

Gillett (1963) monographed Sesbania species in Africa (excluding Madagascar) and southern Arabia, and Sachet (1987) studied the littoral species of Sesbania in the South Pacific. We have accpeted Lavin's (1987, 1995; Polhill 1994a, 1994b) decisions to synonymize Glottidium A.N. Desvaux under Sesbania and that Daubentonia should be maintained within Sesbania. He also created a new combination, Sesbania sect. Glottidium (A.N. Desvaux) M. Lavin. For Lavin (pers. comm.), recognition of Glottidium would render Sesbania paraphyletic. Our studies have found the following differences between Sesbania, sensu stricto, and Glottidium: Sesbania with fruit short tapered or truncate at base, coriaceous or ligneous, with all layers dehiscing, splitting along the sutures, with epicarp wrinkled, with endocarp glossy, septate, coriaceous, remaining fused to mesocarp and epicarp, with 5–40 seeds, with funiculus flattened, with seeds 3–7 mm long, without visible radicle and cotyledon lobes, with testa coriaceous, with hilum concealed by aril, 0.3–1.5 mm long, flush, with hilum rim color lighter or darker than testa, with lens 0.5–1.2 mm long, linear, circular, or elliptic, mounded, with endosperm thick, and with cotyledons lacking basal groin formed by its lobes; versus Glottidium with fruit long tapered at base, membranous, with epicarp and mesocarp dehiscing and endocarp not dehiscing, with epicarp and mesocarp splitting along suture, endocarp entire, forming an envelope around the seeds with flat winglike areas, with epicarp warty, with endocarp dull, nonseptate, chartaceous, separating from mesocarp, with 1–2 seeds, with funiculus filiform, with seeds 10–12 mm long, with with visible radicle and cotyledon lobes, with testa osseous, with hilum concealed by funicular remnant 3.8–6.5 mm long, recessed, with hilum rim color of testa, with lens 1.9–3.25 mm long, oblong, flush, with endosperm thin, and with cotyledons having a basal groin formed by lobes. Sesbania sect. Glottidium, unlike other faboid legumes, except Endosamara, has the epicarp and mesocarp portions of the valves separating from the endocarp freeing the winged chartaceous endocarp bearing two or one seeds. The two-seeded endocarp remains intact, while in Endosamara the multiseeded endocarp separates into lomentlike segments, each with a single seed. We agree with Lavin (1987) that "the diversity of the legumes and seeds of Sesbania is unrivalled among related genera." Lavin and Sousa (1995) erected an infrageneric classification for Sesbania which included Glottidium as a section, see Notes for Glottidium. Manning and Van Staden (1987a) discussed the role of the lens in seed imbibition.

Tribal Notes

Tribe Robinieae

The genera, generic groups, and related data follow the tribal treatment of Lavin and Sousa (1995; Polhill, 1994a, 1994b), not Polhill and Sousa (1981).