Perennial herbs, sometimes suffrutescent, root parasites. A rootstock or stolons sometimes present. Stem simple or branched. Leaves alternate, sessile, linear to lanceolate (in our species), entire, l-3(-5) nerved. Inflorescence a raceme or a panicle. Bract solitary, bracteoles if present, 2. Perianth tubular to campanulate, 5-lobed (in our species), persistent. Disk obscure. Anther dehiscence longitudinal. Fruit a nut.
A complex genus, nomenclaturally and taxonomically; different authors have accorded it substantially different treatments. Until an overall revision of the Sino-Himalayan species is available, many of the currently accepted species and their limits must be regarded with some uncertainty.
A genus of c.325 species, mainly distributed in S. Africa, but also in Europe, Asia and Australia. Represented in Pakistan by 2 species.
Taxa incorrectly recorded
Thesium pachyrhizum A. DC., Prodr. 14:646.1857.
Duthie 11957 (K) from Karpuchu Valley (Baltistan) has a thick rootstock as in Thesium pachyrhizum, but it is Thesium hookeri var jarmilae. Thesium pachyrhizum has very slender, simple and erect stems and deep cleft, short more or less cupular flowers.
Thesium divaricatum Jan. ex Mertens & Koch in Rohling, Deutschl. Fl. ed. 3, 2:286. 1826.
J.R. Drummond 14496 from Sakesar (Jhelum Dist.) and Aitchison 339 from Kurram has been identified with this species. Thesium divaricatum is mainly a S. European species and differs in the shorter bract and bracteoles, which are more or less equal in size, and the nut which is only longitudinally veined (not reticulate).
