Prosopis ruscifolia Griseb.
Family Fabaceae, Subfamily Mimosoideae
NOTE: Only three seeds of Prosopis ruscifolia were available for examination. Therefore, the description and images in this fact sheet may not be representative of this species’ seeds.
Pods linear, straight to subfalcate or with a twist (S-shaped), compressed, 13–29 cm long, 9–11 mm wide, 2–5 mm thick. Stipitate, apex short-tapered to caudate, margins undulate. Smooth, speckled or streaked with darker color, longitudinal striate ridges; seed chambers 10–30. Endocarp segments boney, closed, rhombic, 5–8 mm long and wide, 1–2 mm thick; mesocarp often semi-fleshy and sweet. Seeds oriented longitudinally.
Seeds obovate to broadly or asymmetrically obovate in outline, 4–7 mm long, 3.2–4.7 mm wide, 1–2.2 mm thick, umbo not very prominent, +/– elliptic in cross section. Pleurogram average to wide. Lens a light-colored mound.
Prosopis flexuosa DC. (Pod is similar). [No image available.] (non-FNW)
Prosopis vinalillo Stuckert (Pod is similar) [No image available.] (non-FNW)
Argentina, Bolivia, Brazil, Paraguay
thickets, open woodlands, park-like grasslands
Prosopis ruscifolia is a spiny tree, 5–12 m tall, that is considered a serious weed in Argentina. The plants form dense, spiny, impenetrable thickets that prevent livestock from grazing and result in abandonment of these lands. Livestock and herbivores relish the sweet pods, thereby dispersing the seeds widely. The leaves contain a substance that inhibits germination of other seeds. When full grown, it yields good timber.