Frémont’s desert-thorn

Lycium fremontii var. congestum C. L. Hitchcock

Shrubs erect, 1–3 m; bark tan, gray, or brown; stems densely glandular-pubescent. Leaves: blade bright green, spatulate, 8–35 × 2–15 mm, fleshy, surfaces densely glandular-pubescent. Inflorescences 2–3-flowered fas­cicles or solitary flowers. Pedicels 4–25 mm. Flowers bisexual or pistillate, 5-merous; calyx tubular, 2–10 mm, lobes to 1–2 mm, glandular-puberulent; corolla deep lavender to purple, tubular to funnelform, 8–20 mm, lobes 2–8 mm; stamens included to slightly exserted. Berries red, ovoid, 5–9 mm, fleshy. Seeds 40–60. 2n = 96, 120.

Flowering Jan–Apr. Sandy washes, saline flats (Sonoran Desert); 100–1300 m; Ariz., Calif.; Mexico (Baja California, Baja California Sur, Sonora).

Lycium fremontii occurs in the Sonoran Desert of Arizona, southern California, and northwestern Mexico. Populations of L. fremontii are morphologically gyno­dioecious (functionally dioecious), and plants are sexually dimorphic for flower size. Pistillate plants are often covered with orange-red berries in March and April. Plants are robust; in southern Arizona they often thrive at the edges of agricultural fields, where there is water run-off. This species co-occurs with L. andersonii, L. berlandieri, and L. californicum. However, the com­bination of larger bright green leaves, deep lavender flowers, floral dimorphism, and considerable glandular pubescence differentiates this species.