Genista tridens (Cav.) DC.
Spartium tridens Cav.
Spa.: Aulaga, aliaga. Fre.: Genêt. Ara.: Guendul.
Shrub or subshrub up to 0.6 m in height, spiny, hermaphrodite, highly branched, with erect stems, sparsely foliose. Stems and old branches with brown bark, fissured longitudinally, glabrous. Young branchlets green, striated-ribbed longitudinally, with 5-8 ribs in an inverted V-shape, puberulous, finishing in a spine. Spines simple or pinnate. Leaves alternate, trifoliolate or unifoliolate —with the lateral leaflets transforming into 2 spiny appendages—, without stipules, subsessile, with leaflets 3-8(10) × 0.5-1.7(2) mm, lanceolate, attenuated at the base, acute or spinulose at the apex, green, glabrescent on both sides, with spinescent phyllodes at the base. Inflorescence racemiform, terminal, ± lax, often with the axis prolonged into a spine, and with 5-25 pedicellate flowers, with pedicel up to 2 mm, glabrous. Calyx 3-4.5 mm, glabrous, deeply split into 2 lips, the upper lip bipartite in 2 triangular segments, and the lower lip trifid. Corolla 5.5-7.5 mm, papilionoid, yellow, caducous, with an ovate standard, truncated at the apex, glabrous, subequal to the wings and subequal or smaller than the keel. Androecium monadelphous, with 10 stamens. Ovary puberulous and capitate stigma. Pod 5-6 × 2.5-3 mm, ovoid-acuminate, compressed, reddish-brown or blackish, puberulous, with 1 seed. Seeds 1.5-2 mm, ovoid, somewhat compressed, smooth, brownish, without an aril.
Flowering:
April to June.
Fruiting:
May to July
Habitat:
Woodland and thickets on siliceous or somewhat decalcified terrains, in humid and subhumid environments.
Distribution:
Southern region of the Iberian Peninsula and NW Morocco.
Observations:
Polymorphic species, of which there are 2 recognised subspecies, both represented in North Africa. G. tridens subsp. tridens includes plants with all leaves unifoliolate and simple spines, distributed across the Tingitana Peninsula (Morocco), and also in southern Spain. Conversely, G. tridens subsp. juniperina (Spach) Talavera & P.E.Gibbs (G. juniperina Spach, G. oxycedrina Pomel) includes plants with unifoliolate, bifoliolate or trifoliolate leaves and branched spines; it grows in cork oak forests (Quercus suber) in southern Spain and in the central and western Rif.
Conservation status:
This species is not considered threatened, however its populations cover a relatively small area. Currently, it has not been assessed at a global level in the IUCN Red List of Threatened Species.