Greuteria argyrea (Greuter & Burdet) Amirahmadi & Kaz. Osaloo
Hedysarum argyreum Greuter & Burdet, H. argentatum Maire, non L. f, nom illeg.
Ara.: Al markh.
Evergreen shrub or small tree, hermaphrodite, up to 3(5) m in height, very ramose, branching upright or, in larger and older specimens, extended-upright. Trunk and older branches with greyish-brown bark, that peels off into longitudinal strips, often filiform. Young branches (of a few years) angular, brown-greenish, younger ones green, with short and applied hairs. Leaves 1.5-3 cm long, alternate, fleshy, rigid, covered in short, white and applied hairs (silky), imparipinnate, with rachis proportionately much wider than the leaflets, compressed, with 3-11 leaflets, 0.3-0.5 mm long, alternate or subopposite, elliptical, obtuse or subacute, briefly attenuated at the base, sessile, fleshy, green on both sides. Inflorescence in racemes, axillary, sparse, with 2-6 flowers, shortly pedicellate, sometimes flowers solitary. Calyx campanulate, with 5 short subequal teeth, shorter than the tube, brown, with applied hairs. Corolla papilionoid, purple, with standard base pinkish; wings very short, pink or purple; keel purple, with the lower part white-pink. Androecium diadelphous. Ovary semicylindrical, stipitate. Pod reddish-purple, oblong, highly compressed, papery, divided into 2-3 ellipsoid-orbicular segments, each with a seed inside.
Flowering:
April to July.
Fruiting:
July to September. Sometimes the same plant can bare both flowers and ripe fruit (as can be seen in the photograph, taken in July).
Habitat:
Dune fields in littoral or sublittoral desert terrains, which benefit from a relatively high atmospheric moisture.
Distribution:
Endemic to North Africa. Littoral or sublittoral dune fields of NW Sahara (Tarfaya and Al Aaiun ).
Observations:
This shrub is highly palatable for goats and cut frequently for firewood and timber. In a desert area, where all natural regeneration of vegetation is slow, continued exploitation of this species has made it locally extinct or rare in many areas. Under natural conditions, these shrubs can be completely covered by sand and still stay alive, so it is possible that, originally, they formed woods that fixed the dunes. Both the scientific value of this rare endemic species, and its important ecological and economic value for dune stabilisation would make this species ideal for the repopulation of dune fields within its native range. The economic cost of reforestation could eventually be much lower than the cost of using heavy machinery to clear sand off roads during much of the year.
Conservation status:
G. argyrea is fairly rare species with a very small Distribution. Currently, it has not been assessed at a global level in the IUCN Red List of Threatened Species.