A dwarf, deciduous, very spiny and much branched shrub of whitish aspect growing to about 1 ft high in the wild state. The old wood is completely covered with the closely set, sheathing bases of stiff, sharp spines 1 to 21⁄2 in. long, which are really the persistent rhachises of the leaves become hard with age. These spines remain on the plant for many years and serve to protect the young leaves from browsing animals. Leaves pinnate, composed of six to twelve pairs of leaflets set on a spine-tipped rhachis; leaflets 1⁄8 to 1⁄4 in. long, oblong to elliptic, bluntly pointed, covered on both sides with silky hairs. The leaves are furnished with hairy stipules which are united to the petioles for about a third of their length. Flowers white, borne three to eight together in a raceme which is as long as or shorter than the leaves. Calyx tubular, about 1⁄4 in. long, appressed-hairy, the teeth rather short, being at the most one-third the length of the tube; corollas peaflower-shaped, the standard ovate, about 3⁄5 in. long. Pods about 2⁄5 in. long, appressed-hairy, protruding from the persistent calyx.
A native of the north-west Mediterranean, found mostly in sandy or rocky places by the sea; probably introduced in 1640. It is suitable for a sunny ledge in the rock garden, in very well-drained soil.
This species is part of A. tragacantha L., but this name is best rejected as ambiguous, since Linnaeus included under it one, perhaps two, other distinct species. The identity of the plant that was described under this name in previous editions is uncertain, but the text figure agrees well with A. massiliensis and has therefore been retained.
A. sirinicus Ten. – This species is closely allied to A. massiliensis. It is usually of denser habit and at high altitudes and in exposed places forms hedgehog-like hummocks. The teeth of the calyx are relatively longer (up to one-half as long as the tube); hairs of calyx spreading. Flowers yellow or purplish. Pods with long rather spreading hairs, or almost glabrous. This species is of wider distribution than A. massiliensis (Corsica, Sardinia, Italian Apennines and parts of the Balkan peninsula) and is mainly an inhabitant of mountains. It is part of A. tragacantha as understood by some botanists.
A. angustifolius Lam. – A dense shrub, forming a hedgehog-like mound about 8 in. high. Leaflets in three to ten pairs, narrow-oblong, about 1⁄5 in. long, clad with silvery grey hairs at first, later more or less glabrous. Flowers creamy white, sometimes with a violet blotch at the tip of the keel, borne in July and August in almost sessile clusters of three to eight. Native of the Balkan peninsula and of Crete. A more attractive plant than the other two described, for a sunny, well-drained position in the rock garden. A. pungens Willd., found in Greece, is closely related, but has longer-stalked clusters, with up to twelve flowers in each.
The three species described belong to the section Melanocercis, characterised by the spiny rachis and by the peculiar hairs, which are two-branched and keeled at the base, but lie appressed to the leaf or stem and have the appearance of single hairs attached by their centres.