Prosopis alpataco Phillipi
Family Fabaceae, Subfamily Mimosoideae
NOTE: Very few seeds (less than ten) of Prosopis alpataco were available for examination. Therefore, the description and images in this fact sheet may not be representative of this species’ seeds.
Pods linear, subfalcate or rarely subannular or S-shaped; 7–17 cm long, 6–12 mm wide, ca. 5 mm thick. Short-stipitate, apex short-tapered, margins distinctly undulate (submoniliform), or almost straight. Smooth, straw-yellow, frequently violet-tinged, veins are faint, mostly parallel longitudinal striations; seed chambers 8–18. Endocarp segments subquadrate to ovate, boney, closed, 8–11 mm long, 9–10 mm wide, 4–5 mm thick; mesocarp scarcely pulpy, bitter or sometimes sweet. Seeds oriented longitudinally.
The pod is variable in appearance and often violet-tinged, which is not uncommon in the series Chilensis.
Prosopis alpataco is a spiny shrub, 20 cm – 3 m tall which starts from thick underground horizontal branches. It is somewhat variable in its fruit and foliage, but varieties have not been distinguished. Livestock and wildlife do not eat the bitter pods, so the seeds of P. alpataco are most likely not animal-dispersed.