Convolvulus trabutianus Schweinf. & Muschl.
Ara.: Ferskil, gendul, bu sabbod.
Subshrub, spinescent, hermaphrodite, up to 1 m in height, erect, with intricate branching. Branchlets sometimes ending in spines. Bark of branches and branchlets covered with an indumentum of short hairs, applied, whitish, giving the subshrub a whitish-greyish general appearance. Leaves from obovate to lanceolate-spatulate, generally obtuse or retuse, sometimes emarginate, flat or concave, with short hairs, green-silvery. Inflorescences at the top of the branchlets, in small cymes of 1-3 flowers. Calyx with 5 sepals (3.5-5 mm), ovate, concave, scarious. Corolla (15-20 mm), white, slightly lobulate at the end, with 5 sharp longitudinal pink bands, sericeous on the outside. Ovary hirsute. Style glabrous or hirsute. Fruit an ovoid capsule, slightly glabrescent, opening in 4 valves. Seeds (2 × 3 mm), ovoid, subtrigonal, matt brown and with white applied hairs.
Flowering:
Almost all year round, especially after rainfall.
Fruiting:
1-2 months after flowering.
Habitat:
Silty or slightly rocky terrains, regs, grasslands in arid and desert areas, up to about 1,800 m in altitude.
Distribution:
Endemic to North Africa, western and north-western Sahara. To the N it reaches the southern foothills of the High Atlas and the western Saharan Atlas.
Observations:
A very similar species is C. lanatus Vahl (Ara.: Bayad, rokham), smaller in size (up to 50-60 cm), with similar leaves and flowers, but it differs by having only the oldest basal branches spinescent, branchlets and calyces densely tomentose, and flowers in larger groups (2-6). It grows in similar areas, mainly in dunes and desert plains, but much further to the E, from Turkey to the Arabian Peninsula. In North Africa it is only known from Egypt, where it becomes common in some northern areas.
Another species, also spinescent but very different, is C. hystrix Vahl (C. spinosus Forssk., C. armatus Delile) (Ara.: Shobroq), with long creeping stems (sometimes more than 1 m) lignified at the base, densely villous. Branches spiny and intricate. Leaves (0.3-1.2 × 0.2-0.4 cm) with acute apex, attenuated or auriculate at the base, with entire or ciliated margin. Flowers in axillary groups of 2-6, with bracts (4-6 × 3-4 mm) and bracteoles (5-7 × 3-5 mm). Sepals (7-9 × 6-8 mm) are unequal: the 2 external sepals wide and obovate, while the 3 internal sepals oblong and mucronate. Corolla 1-1.3 cm, blue and with hairy bands on the lower surface. Fruit a monospermous capsule, c. 3 × 2.5 mm, obovoid. Seeds ovoid, glabrous and brown-greyish. It grows on sandy substrates along watercourses and desert plains, distributed through the Arabian Peninsula and NW Africa (from Egypt to Somalia).
Conservation status:
Rare but widely distributed species. Currently, they have not been assessed at a global level in the IUCN Red List of Threatened Species. In the Livre Rouge de la flore vasculaire du Maroc (Fennane, 2021) C. trabutianus has been considered as Near Threatened (NT). In the updated red list of Egypt (Shaltout & Bedair, 2023) C. hystrix has been considered as Near Threatened (NT).