Astragalus armatus Willd.
Acanthyllis armata (Willd.) Batt., Anthyllis tragacanthoides Desf., Astragalus fontanesii Coss. & Durieu ex Bunge
Eng.: Milkvetch. Fre.: Astragale vulnérant. Ara.: gdad, gundal, chuk ed derban, tusent, archkuch, iwusked. Tam.: Tiwskett, guettèt.
Subshrub, up to 60(70) cm in height, very spiny, hermaphrodite, highly branched and sometimes intricate, ± hemispherical in shape. Stems and old branches tortuous, with brown-greyish bark. Young branchlets greenish, slightly tomentose. Leaves alternate or subopposite, all borne closely together at the end of the branches, paripinnate; with rigid rachis, strongly spiny, about 3-6 cm long, first green, then whitish; with 3-9 pairs of leaflets, shortly petiolulate, entire, lanceolate, obtuse or subacute, hairy or glabrous on the upper side and always hairy on the underside. Inflorescences in axillary racemes of 1-4 flowers. Calyx ovoid-tubular, with 5 subequal sepals, reddish-white, tomentose-hirsute. Corolla white-pinkish, sometimes bluish, with standard larger than the keel and the wings. Androecium diadelphous. Ovary sessile. Pod included in the persistent calyx, globular and papery, with 1-4 seeds.
Flowering:
March to June.
Fruiting:
June to September.
Habitat:
Thickets and steppic areas in continental plateaux and mountains. In semiarid to humid bioclimate, on thermomediterranean to oromediterranean floors.
Distribution:
Endemic to North Africa. Very widespread in steppes and mountains from Morocco to Tunisia and localised in Libya. Towards the S it reaches the Anti-Atlas and the high plateaux of the northern Sahara. Towards the N it extends mainly from western Rif up to the Djurdjura Massif.
Observations:
There are 2 subspecies. A. armatus subsp. armatus (A. armatus subsp. tragacanthoides (Desf.) Emb. & Maire) has leaves with 3-5 pairs of leaflets, glabrous or glabrescent on the upper side, calyx lobes up to 1.5 mm long, triangular, and pods with 2-4 seeds; it grows mainly along plains and mountain steppes at low and medium altitude in Morocco, Algeria and Tunisia. A. armatus subsp. numidicus (Coss. & Durieu ex Murb.) Tietz, has leaves with 5-8 pairs of leaflets, villous on both sides, calyx lobes 3-4 mm, subulate and pods with 1-2 seeds; it grows in middle and high mountains acrosss the range of the type species and also in Libya.
Conservation status:
A relatively common and widespread species, not considered threatened. Currently, it has not been assessed at a global level in the IUCN Red List of Threatened Species.