Kobresia

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Kobresia

Description

Perennial herbs with short rhizome, monoecious, rarely dioecious. Leaves tristichous, narrowly linear, often convolute, crowded near the base of the stems or also cauline; Inflorescence consisting of a single terminal spike or of several panicled spikes; Flowers unisexual, achlamydeous (destitute of perianth or hypogynous bristles);

Distribution

Asia: present Asia-Temperate:, China South-Central (Yunnan present); Tibet (Tibet present) Asia-Tropical: Europe: present Himalaya: present Madagascar: present N. America: present Szechuan: present northern hemisphere: present
In its usually accepted circumscription the genus comprises c. 40 spp. all occurring in the northern hemisphere. A few arctic-alpine species are known from Europe and N. America; the centre of development is in Asia, especially the Himalaya, Tibet, Yunnan, and Szechuan. In Malesia 1 sp., originally referred to the African genus Schoenoxiphium (c. 10 spp., 2 in Madagascar). It seems impossible to separate Schoenoxiphium from Kobresia on morphological grounds.

Notes

Phylogenetically Kobresia is undoubtedly to be considered the prototype of Carex, from which genus it is difficult to separate in morphological terms. In Carex the margins of the prophyll subtending the female flower have become completely connate, leaving only a small orifice at the apex through which the style protrudes; the prophyll has become a bottle- or sac-like organ called a utricle or perigynium. In Kobresia the margins of the prophyll may be free (as in the Malesian sp.) or more or less connate (rarely almost to the top). In Carex the lateral spikelets are reduced to a single female flower; their axes are vestigial and bear only the female flower surrounded by its utricle; very rarely the axis is still present as a setiform rudiment enclosed in the utricle. In the lateral spikelets of Kobresia the axis is well developed as a rule, bearing a basal female flower and 1-several superposed male flowers. The terminal flowers of each spike are male. The number of male flowers in the lateral spikelets may vary in one inflorescence: from several in the lower spikelets of each spike to none in the upper ones; also in the latter case the rachilla is usually present as a setiform or flat rudiment. In the Kobresias with compound inflorescence the base of each lateral spike bears also a prophyll (here called cladoprophyll), which may or may not contain a female flower.

Citation

CLARKE - in J. Linn. Soc Bot. 1883: 376
BENTH - in B. & H., Gen. Pl. 3. 1883: 1072
KERN - in Act. Bot Neerl. 1958: f. 1-3
KUNTH - in En. 1837: 532
KUNTH - in En. 1837: 528
BENTH. - in B. & H., Gen. Pl. 3. 1883: 1071
CLARKE - in J. Linn. Soc. Bot. 1883: 382
BOECK. - in Linnaea. 1875: 2
BOECK. - in Linnaea. 1877: 352
CLARKE - in Fl. Br Ind. 1894: 694
BENTH. - in B. & H., Gen. Pl. 3. 1883: 1072
KÜK. - in Pfl. R. 1909: 33
KÜK. - in Pfl. R. 1909: 28