Bupleurum L.

This is one of the genera of the Apiaceae family with the largest number of species (some 200 recognised species); all, except one, distributed throughout the northern hemisphere. In North Africa there are about 30 species, mostly herbaceous, about 10 have somewhat woody stems; of these, only 3, B. fruticosum, B. gibraltaricum and B. dumosum, can be considered true shrubs. There are a further 22 species of the genus in North Africa. Although none of these have the minimum size and lignification to be considered shrubs, the tallest and/or most lignified are listed below:

B. montanum Coss., a subshrub with floriferous stems up to 1.3 m long, lignified at the base; leaves linear, flexible, solitary, spaced along the stems and also importantly in a basal rosette (in several publications, it has been indicated that the leaves did not form basal rosettes in this species, surely guided by the description given by Cosson in 1856); venation slightly marked; umbels with 3-15 very slender rays; endemic to North Africa, in the forests and rocky outcrops of medium and high mountains (1,000-2,300 m) of Morocco (Rif, Middle Atlas, High Atlas and western Anti-Atlas) and Algeria (Tellian Atlas and Aures Massif).

B. atlanticum Murb., is another Algerian-Moroccan endemic species, also with linear leaves, but rigid; also well differentiated by its shorter stems (30-70 cm), branched at the end and by umbels with fewer rays (3-5); it grows in almost all the atlasic mountain ranges of Morocco; in Algeria, it grows in the Saharan Atlas and in some mountains of the western area of ​​the steppic plateaux.

B. canescens Schousb. is a subshrub with erect stems, woody at the base, up to 1.30 m in height; leaves ovate-lanceolate, obtuse, coriaceous, with 5 clearly marked veins and umbels with 5-7 rays. It is distributed through the Macaronesian area littoral and sublittoral areas of Morocco; it also grows further inland through the Sus Valley and up to the mountains close to the Aioun du Draa.

B. lateriflorum Coss. is a subshrub up to 0.6 m in height; leaves oblong, subsessile, coriaceous, with denticulate margin, and axillary umbels very numerous along the stems —terminal umbels with 6-7 rays—; endemic to Morocco, to the western High Atlas, western Anti-Atlas and the Siroua Massif.

B. foliosum Salzm. ex DC. is an upright subshrub up to 1 m in height, with leaves grouped near the end of the woody branches; leaves coriaceous, lower leaves linear-lanceolate, upper leaves ovate; umbels with only 2-3 rays; Iberian-Mauritanian endemic, very rare in North Africa, because it is scarce and it is only found in the NW corner of the Tingitan Peninsula.

B. plantagineum Desf. is a subshrub with long stems (up to 1.5 m), woody only at the base; leaves lanceolate, with 5-9 very visible veins, and umbels with 8-20 rays, very short; endemic to Algeria, to the littoral calcareous rocky outcrops of Little Kabylia.

B. rigidum L. is a subshrub with a woody base, robust and with long stems (up to 1.5 m) hardened at the base, but slightly or not lignified, erect or extended among the nearby shrubs or rocks; leaves polymorphic according to the part of the plant and the subspecies and varieties, but ± oblong, with clearly marked marginal veins; umbels with 2-4(5) rays; fairly rare species, although widely distributed through the mounts of the centre and the NE of Morocco and, in Algeria, mainly in the mounts of the high steppic plateaux and the Saharan Atlas.

B. spinosum Gouan, is a spiny subshrub, very ramose, intricate, up to 0.6 m in height, with a characteristic hemispheric shape; leaves linear-lanceolate, glaucous, and umbels with 2-7 rays. It grows in the high mountains (1,000-3,400 m) of SE of Spain and NW Africa. In North Africa it can be locally abundant: Rif, Middle Atlas, High Atlas, Anti-Atlas, Tellian Atlas (rare) and Saharan Atlas. It is also found in the highest mountains of the Algerian-Moroccan steppes. In Flora Iberica, it is considered a subspecies of B. fruticescens L., a species not mentioned in North Africa, but which actually would be, represented by the subsp. spinosum (Gouan) O.Bolòs & Vigo.

Species not very common in general, even rare, but exceptionally abundant very locally. Currently, they have not been assessed at a global level in the IUCN Red List of Threatened Species.

Updated by: M. Cueto & E. Giménez.