Thymelaea Mill.
Genus composed of about 31 species of Palearctic distribution. In North Africa it is represented by 16 species, all with a Mediterranean distribution, although with some encroachment into Saharan territory (Th. microphylla). They are shrubs, subshrubs, suffrutescent perennials and annual herbaceous plants.
Of the woody species, 11 can be classified as shrubs or subshrubs, although 2 are very small (<15 cm). The latter species are Th. putorioides Emb. & Maire, endemic to the limestone rocky outcrops of the central High Atlas; and Th. virescens Meisn., endemic to North Africa (Morocco and Algeria) in open forests and pastures of the High Atlas, Middle Atlas, Saharan Atlas and the Aures Massif. Both of them are rare and with small distribution areas. Currently, they have not been assessed at a global level in the IUCN Red List of Threatened Species.
The remaining species are suffrutescent perennials (Th. virgata (Desf.) Endl. and Th. antiatlantica Maire) or annual herbaceous plants (Th. passerina (L.) Coss. & Germ., Th. salsa Murb. and Th. gussonei Boreau).
Galicia Herbada, D. 2006. Origin and diversification of Thymelaea (Thymelaeaceae): inferences from a phylogenetic study based on ITS (rDNA) sequences. Plant Systematics and Evolution 257(3-4): 159-187.
Galicia Herbada, D. 2003. Relaciones filogenéticas en Thymelaea Mill. y entre éste y otros géneros próximos basadas en el análisis de caracteres morfológicos y moleculares; implicaciones evolutivas, biogeográficas y taxonómicas. Tesis Doctoral. Universidad Autónoma de Madrid.
Tan, K., 1980. Studies in the Thymelaeaceae II: a revision of the genus Thymelaea. Notes from the Royal Botanic Garden, Edinburgh, 38(2): 189-246.
Key to species
1 Shrubs with bracteate inflorescences in axillary glomerules 2
1 Shrubs or subshrubs with ebractate inflorescences in terminal glomerules (sometimes also at the end of very short brachyblasts which makes them look axillary) 3
2 Leaves appressed-pubescent, spatulate. Inflorescences with 2-5 flowers Thymelaea tartonraira
2 Leaves glabrous, elliptic-lanceolate. Inflorescences with 7-20 flowers Thymelaea sempervirens
3 Subshrub < 15 cm, with young stems and leaves glabrous, glabrescent, or puberulous 4
3 Shrub or subshrub > 15 cm, with young stems and leaves villous (with long and patent hairs), lanuginous, tomentose or pubescent 5
4 Leaves completely glabrous. Stems thick, ± decumbent and tortuous. Inflorescences with more than 7 flowers. Flowers green Thymelaea virescens
4 Leaves puberulous or glabrescent. Stems thin, erect and ± straight. Inflorescences with less than 7 flowers. Flowers yellow-greenish or yellow-pink Thymelaea putorioides
5 Young stems and leaves villous (with long and patent hairs) or completely and abundantly lanate 6
5 Young stems and leaves with a different kind of pilosity 8
6 Young stems and leaves villous (with long and patent hairs). Inflorescences with less than 6 flowers Thymelaea villosa
6 Young stems and leaves completely and abundantly lanate. Inflorescences with more than 6 flowers 7
7 Inflorescences in glomerules of 7-10 flowers Thymelaea lanuginosa
7 Inflorescences in glomerules of 9-14 fowers Thymelaea gattefossei
8 Leaves glabrous and green beneath, and covered by a dense white tomentum above 9
8 Leaves pubescent beneath and above, sericeous 10
9 Leaves thick, incurved, ± appressed. Hypanthium caducous Thymelaea hirsuta
9 Leaves thin or slightly thick, flat (only incurved at the tip), with a tendency to become patent. Hypanthium persistent Thymelaea lythroides
10 Leaves ovate or elliptic-lanceolate, obtuse, ± spaced apart. Young stems covered in dense white tomentum Thymelaea microphylla
10 Leaves linear-lanceolate or linear-spatulate, ± acute, imbricate. Young stems with greyish pilosity Thymelaea argentata
Updated by: D. Galicia Herbada.