Carex tristachya var. pocilliformis

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Carex tristachya var. pocilliformis

Description

Leaves basal and subbasal, as long as or shorter than the stems, rather rigid, flat, gradually attenuate, 1.5-4 mm wide. Inflorescence with 3-7 spikelets, erect, fastigiate or lower spikelets more distant on exserted peduncles; Stamens monadelphous (filaments connate almost throughout their length), not always so in lower flowers.

Distribution

Asia-Temperate: Korea presentpresent, Asia-Tropical: Borneo present; New Guinea present; Philippines (Philippines present), Benguet present, Central and Eastern China present, Japan present present, Luzon present, Mt Kinabalu present, Mt Pulog present, Mt Sarawaket present, Ryu Kyu Is present, Southern America: Argentina Northeast (Formosa present)
Var. tristachya occurs in Japan, Korea, Central and Eastern China, var. pocilliformis is also in Japan and Korea, but extends more southwards, through the Ryu Kyu Is. and Formosa to Malesia: Philippines (Luzon: Benguet: Mt Pulog), Borneo (Mt Kinabalu), and New Guinea (NE.: Mt Sarawaket).

Notes

Carex tristachya is remarkable for its monadelphous anthers, a feature very rare in the genus (according to Barros also found in C. acaulis d'Urv. of the Falkland Is. [cf. ]).
There is no agreement on the taxonomical status of C. pocilliformis Boott. Whereas Clarke () did not distinguish it from C. tristachya, it was reduced to varietal rank by Kukenthal, Ohwi, and others, but maintained as a distinct species by Nelmes and Akiyama. The main difference is to be found in the glumes of the 3 flowers, which are said to have free margins in typical C. tristachya. I think the difference is only gradual, as in the latter the margins of the glumes are also connate, though at the very base only.
Glumes with united margins are very rare in the genus; they are also known in some North American species belonging to sect. Phyllostachyae Tuckerm. (see ).
Carex tristachya is very near to C. mitrata Franch. & Sav., the main difference being in the male spikelets, of which the glumes are infundibuliform and the filaments connate in C. tristachya. But in C. tristachya var. tristachya the margins of the glumes are connate at the very base only, and sometimes they are free. Besides, even in var. pocilliformis, I found perfectly free filaments and anthers, especially in the lower flowers (e.g. Merrill 6629). It is very well possible that the mentioned characters in the male spikelets are not very important, and that C. tristachya and C. mitrata have to be considered as subspecies of a single species. — (Noot.).

Citation

Kuk. 1911 – In: Philip. J. Sc. Bot. 62
Merr. 1923 – In: En. Philip. p 142
Nelmes 1949: Kew Bull. p 391
Ohwi 1936 – In: Mem. Coll. Sc. Kyoto Imp. Un. p 364
Boott 1951 – In: Reinwardtia. p 381
Akiyama 1955: Car. Far East. Reg. Asia: 196. t. 199
Yoshikawa 1957: p. 120. – In: Ic. Jap. Carex. t. 60