Cullen plicatum (Delile) C.H.Stirt.
Psoralea plicata Delile, P. odorata Blatt. & Hallb., Munbya polystachya (Poir.) Pomel
Eng.: Scurfy-pea. Ara.: Djettiat, hama, marmeid. Tam.: Tareda, taghaedda, amarkoess.
Subshrub 30-60(150) cm in height, hermaphrodite, erect, with woody stems, at least at the base, with whitish bark. Young branchlets herbaceous, slender and long, angular, greenish-whitish, villous, with erect hairs, glandular. Leaves alternate, trifoliolate; central leaflet 1-3.5 × 0.5-1 cm, petiolule up to 10 mm; lateral leaflets 0.6-2 × 0.4-0.8 cm, petiolule c. 1 mm, oblanceolate, obtuse, briefly lobulate and very undulate, green and with short hairs on both sides, with numerous small black glands on the upper side. Inflorescences in terminal racemes, ± long and lax; flowers in small groups of 1-3 —sometimes fairly spaced apart—, pedicellate. Bracteoles 1(2) mm. Calyx 3-4.5 mm, tubular-campanulate, with 5 teeth, ovate-lanceolate, subequal, greenish, with brown-purple venation, pubescent. Corolla 3-7 mm, papilionoid, glabrescent, pinkish, with purplish tints, especially on the keel, that is slightly longer than the calyx. Pod 4-5 mm, ovoid, indehiscent, pubescent, included in the calyx, with 1 seed.
Flowering:
February to April.
Fruiting:
May to June.
Habitat:
Plains and depressions in sabanas, semideserts and deserts, often sandy. Sometimes it behaves as a ruderal or it grows in cultivated areas.
Distribution:
Saharo-Sindian region. From the western Sahara to India. In North Africa it is a common species in the southern and central areas of the Sahara, reaching towards the N up to Morocco (S of the Anti-Atlas) and most of the Saharan Algeria, Lybia and Egypt.
Observations:
There is another species of the same genus in North Africa, C. americanum (L.) Rydb. [Psoralea americana L., P. dentata DC., P. polystachia Poir., Munbya polystachya (Poir.) Pomel.]. Despite its name, it is a native taxon (the names arises from a confusion from the original description, when it was believed to be a cultivated species from seeds brought from America). It is a herbaceous plant, somewhat lignified at the base, which can exceed 1 m in height. It grows in the western Mediterranean, in Macaronesia (Canary Islands and Madeira) and in the Mediterranean regions of North Africa (Morocco, Algeria, Tunisia and Libya). It grows on deep clayey soils along deep valleys and it often behaves like a weed on cereal crops.
Conservation status:
Rare species but widely distributed, they are not considered threatened. Currently, C. plicatum has not been assessed at a global level in the IUCN Red List of Threatened Species, while C. americanum is listed in the IUCN Red List of Threatened Species as Least Concern (LC) at a global level (Daoud-Bouattour et al., 2010).
