Prosopis castellanosii

Name and classification

Prosopis castellanosii Burkart
Family Fabaceae, Subfamily Mimosoideae

NOTE: Only one seed of Prosopis castellanosii was available for examination. Therefore, the description and images in this fact sheet may not be representative of this species’ seeds.

Common names

mesquite

Description

Pods oblong, compressed, with 1 or more twists, straight or curving slightly, lomentoid, 3.5–8 cm long, 15–20 mm wide, ca. 4 mm thick. Stipitate, mucronate at apex, margins slightly undulate. Reddish-brown, with prominent, reticulate veins; seed chambers ca. 4–10. Endocarp segments subquadrate or broader than long; mesocarp thin, nearly dry. Seeds oriented longitudinally.

Seeds asymmetrically obovate to broadly oblong in outline, ca. 7.5–8.4 mm long, ca. 5–6 mm wide, ca. 2.5–2.7 mm thick, elliptic in cross section. Pleurogram arms nearly closed and extending to base. Lens a light-colored mound.

Identification considerations

The lomentoid, oblong, flat pod is unique and diagnostic for the species.

Distribution

Argentina

Habitat

arid hills at 600–1300 m elevations, very isolated

General information

Prosopis castellanosii is a spiny shrub, 0.6–1.5 m tall. An extreme xerophyte, it is quite localized and rare. The lomentoid pod breaks into one-seeded fruit segments.

seed

seed

lens and funiculus remnant of seed

lens and funiculus remnant of seed

pod fragments

pod fragments

A, pod; B, seed; C, longitudinal section of seed showing embryo; D, transection of seed; drawing by Lynda E. Chandler

A, pod; B, seed; C, longitudinal section of seed showing embryo; D, transection of seed; drawing by Lynda E. Chandler