Senna italica Mill.
Cassia italica (Mill.) Spreng.
Eng.: Senna, Port Royal senna, Italian senna, Senegal senna. Spa.: Sen. Fre.: Séné, senne. Ara.: Senna, senna mekki, senha, sana mekki, sanna essudani, achreq, afalajite (Niger). Tamahaq: Aquerquer, ag’erg’er, agerge, agerer, adjerdjer, afelladjit, oegerger, agargar, nananas.
Shrub or tree up to 5 m in height, hermaphrodite, evergreen, erect, very ramose. Stems and old branches with greyish-brown bark, glabrous, younger branches brown-green, applied hairs. Leaves 4-12 cm, alternate, paripinnate, lanceolate, with stipules 3-5 mm, with petiole 1-3 cm, petiole and rachis initially eglandular and hairy, and 3-7 pairs of leaflets 6-25(35) × 9-45 mm, subsessile, obovate or oblong-obovate, somewhat asymmetric, rounded at the apex and usually mucronate, or sometimes somewhat emarginate, attenuate-rounded at the base, entire margin, glabrous —somewhat pubescent when young on the underside—, light green on the upper side and dull on the underside. Inflorescences racemiform, axillary, 2-25 cm, arranged in small clusters, erect, with 10-25 pedicellate flowers, with pedicels c. 4 mm —slightly longer after anthesis—, slightly pubescent. Calyx (5)8-13 mm, with 5 sepals fused only at the base, with lanceolate teeth, glabrous, reddish-brown, open in a star-shape. Corolla with 5 petals 8-12(20) mm, obovate, open in a star-shape, yellow, with purplish-black vernation, glabrous. Stamens 10, free, very unequal, 2 longer stamens, nearly as long as the petals and with linear arched anthers, the medium sized stamens shorter and with erect anthers almost as long as the filament, and the 3 upper stamens transformed into staminodes. Ovary shortly hairy. Pod 2-5.3(6) 1.2 × cm, reniform, highly compressed, rounded at both ends, with papery valves with tenuous transverse ribs and a marked longitudinal ridge formed by a crest or wing developed at each seed, laxly puberulent, with 6-12 seeds separated by septa. Seeds 5-6 × 3-3.5 mm, triangular-obovoid, compressed, finely reticulate, greenish-grey or brown-olive.
Flowering:
February to May or after summer rains.
Fruiting:
2-3 months after Flowering.
Habitat:
Savannahs and desert areas, in drier areas along riverbeds.
Distribution:
Africa and Asia, from Senegal to India. In North Africa it is a common species in the Sahel and in the southern and central belts of the Sahara (reaching 1,500 m in altitude). Towards the N, it reaches the vicinity of Béni Abbès (NW of Algeria), Ghadames (NW Libya) up to the Mediterranean, in the NE of Egypt.
Observations:
There are 2 subspecies recognised in the territory. S. italica Mill. subsp. italica (Cassia aschrek Forssk., C. obovata Collad.) is characterised by its inflorescences of 6-23 cm —which are clearly longer than the axillary leaf— and its flower with a corolla of 9-20 mm; it is distributed in Algeria, Libya and Egypt. Conversely, S. italica subsp. micrantha (Brenan) Lock (C. italica subsp. micrantha Brenan), is distinguished from the previous by inflorescences of 2-8 cm, shorter than the axillary leaf and flowers with a corolla of 8.5-9 mm. It is found in the territory only in Morocco and Algeria, although its overall distribution area spans throughout Senegal, Mali, Somalia and Socotra, and to the S up to South Africa and Namibia; it is also known from India and Pakistan.
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. In Mali it is included in its List of species that need authorization for commercial use (Decree 07-155/P-RM of 2007).