Salsola vermiculata L.

Family: Chenopodiaceae

Common names:  shrubby Russian thistle, wormleaf salsola, mediterranean saltwort

Disseminule:  Fruit

Description

Fruit a 1-seeded utricle with surrounding persistent segmented calyx (sepals), extending into 5 wings: 2 small (minor) wings with expanded limbs, and 3 large, with largest wing between the 2 minor wings. Fruit 6.0-12.0 mm in diameter including wings, 1.0-3.0 mm thick. Wings broad, extending laterally, with fine, light-colored veins; wings usually straw-colored to light brown. Below wings fruit hemispherical, smooth, hardened, often glossy, with a distinct scar. Apex scarious, rough, sparsely pubescent, cone-shaped; triangular calyx segments connivent. Utricle consists of a somewhat flattened spirally coiled embryo covered by thin, membranous pericarp, 2.0-2.5 mm in diameter, 1.0-1.5 mm thick. On one side the retained pericarp forms a ridged cone, on the other a thin layer of pericarp reveals the tightly coiled embryo. Pericarp surface waxy looking, straw colored to orange-yellow, mostly concealing dark brown embryo. Endosperm absent.

Identification remarks

Wing configuration of 2 minor and 3 major wings distinguishes the genus Salsola. Within the genus, the size and shape of the minor wings, prominence of wing venation, and wing orientation are characters used to differentiate species. S. vermiculata wings lack the prominent venation seen in the wings of S. tragus and S. paulsenii. The embryo of S. vermiculata is somewhat flattened, while that of S. tragus is conical.

Similar species

Salsola tragus L.

Salsola paulsenii Litv.

Distribution

Sudan; Asia: Iran, Israel, Jordan, Russia, Syria; Europe: Italy, Portugal, Spain, United Kingdom; United States.

Native to Italy, Portugal, and Spain.

Habitat

Saline and clay soils, sandy arid regions, maritime habitats, rocky slopes, disturbed sites.

General information

Salsola vermiculata is a shrubby perennial, up to ca. 1 meter tall. In the Middle East it is grown in pastures for forage. In 1969 this plant was introduced to California in an experiment to improve forage. After the test site was abandoned, S. vermiculata spread into nearby hillsides and canyons. It is uncommon in California, however, being confined to specific locations in San Luis Obispo Co.

Fruits with persistent calyx

Apex of fruit (above wings)

Base of fruit (below wings)

Fruits (top view) without persistent calyx, showing coiled embryo

Fruits (bottom view) without persistent calyx, showing pericarp

A, Fruit with persistent calyx and bracteoles; B, Fruit with calyx and bracteoles removed; C, Embryo in situ; D, transection of fruit

drawing by Lynda Chandler

Winged fruits (from upper part of plant) with persistent calyx

Fruits (from lower part of plant) with wings broken off, or with absent or reduced wings

Fruit with persistent calyx removed, showing conical shape of embryo

Fruits with persistent calyx, showing apex (left) and base (right)