Prosopis farcta (Sol. ex Russell) J.F. Macbr.

(=Lagonychium farctum (Banks & Sol.) Bobr.)

Family: Fabaceae,  Subfamily: Mimosoideae

NOTE: Only thirteen seeds of Prosopis farcta were available for examination. Therefore, the description and images in this fact sheet may not be representative of this species’ seeds.

Description

Pods globose to cylindric, subfalcate, +/- terete, 1.5-4.5 cm long, 1.5-3 cm wide, 1.3-2.5 cm thick. Short-stipitate, apex globose or mucronate, margins nonundulate, one suture a groove. Smooth, orange-red, becoming black when ripe; seed chambers not visible. Endocarp segmented but not closed, with transverse articles in 2 longitudinal rows, mesocarp spongy. Seeds oriented transversely.

Seeds obovate to broadly elliptic in outline, 6.3-8.5 mm long, 4.5-6 mm wide, 1.7-3 mm thick, without an umbo and sometimes depressed centrally, narrowly elliptic in cross section. Pleurogram with relatively short-arms, broadly open, sometimes distinctly wide and close to margins. Lens recessed, diamond-shaped.

Identification remarks

The shape and dull black color of ripe pods is distinctive. The seeds are also distinctive as they are rather large, and have a rather large pleurogram that usually has a pale colored band on its inner border.

Distribution

Native to Northern Africa (Algeria (rare), Egypt, and Tunisia), and much of southwestern Asia, from Kazakhstan south to the Indian subcontinent and west to the middle east and Asia minor. Also found in the United States.

Habitat

Clayey, dry soils, and deep alluvial soils with shallow ground water; thrives in saline soils under semiarid conditions.

General information

Prosopis farcta is a small, prickly shrub, 30-80 cm tall or “shrub-tree” 2-3 m or taller. In its native range, it is widespread, and a weed of wheat and cotton fields, invading by root suckers. It is a common weed in Israel and Afghanistan. Although not eaten by livestock (because of its spines), other herbivores eat the fruits, thus most likely aiding seed dispersal.

For more information about the genus Prosopis, see the Prosopis fact sheet.

Seeds

Seeds

Lens and hilum of seed

Pods

Pod

Pod opened revealing endocarp chambers

A, Pod; B, seed; C, longitudinal section of seed showing embryo; D, transection of seed

drawing by Lynda E. Chandler