Distichlis

Distichlis is a genus of herbaceous plants belonging to the Poaceae family. It is native to America and Australia.

Description

They are rhizomatous, dioecious perennial plants. Leaves cauline, markedly distichous; the ligule a ciliated membrane; blades linear, flattened to convoluted. Inflorescence a terminal panicle or raceme, contracted, sometimes reduced to 2 spikelets. Spikelets of both sexes similar, laterally compressed, with numerous unisexual florets; disarticulation between florets late in pistillate spikelets; glumes short, membranaceous, carnate, faintly 3-7-veined; lemmas 5-11-veined, coriaceous, glabrous, not awned, keeled; paleas as long as or slightly shorter than lemma, 2-keeled, keels scabrous; lodicules 2; stamens 3; styles 2, thickened at base. The fruit is a sulcate caryopsis; embryo 1/3 the length of the caryopsis; dotted thread.

Taxonomy

The genus was described by Constantine Samuel Rafinesque and published in Journal de Physique, de Chimie, d'Histoire Naturelle et des Arts 89: 104. 1819. The type species is: Distichlis maritima Raf.

Etymology

The generic name derives from the Greek distichos (in 2 rows), referring to the remarkable phyllotaxis.

Cytology

Base number of the chromosome, x = 10. 2n = 40. 4 ploid.

Accepted species

The following is a list of the species of the genus Distichlis accepted up to May 2015, arranged alphabetically. For each one, the binomial name followed by the author is indicated, abbreviated according to conventions and uses.

1. Distichlis steelsa (Griseb.) H. L. Bell & Columbus - Argentina
2. Distichlis australis (Speg.) Villamil - Argentina
3. Distichlis distichophylla (Labill.) Fassett - Australia
4. Distichlis eludens (Soderstr. " H. F. Decker) H. L. Bell " Columbus - Durango, Zacatecas, San Luis Potosí
5. Distichlis humilis Phil. - Peru, Bolivia, Chile, Argentina
6. Distichlis laxiflora Hack. - Argentina
7. Distichlis littoralis (Engelm.) H. L. Bell & Columbus - California, Texas, Louisiana, Florida, Mexico, Bahamas, Cuba
8. Distichlis palmeri (Vasey) Fassett ex I.M.Johnst. - Baja California, Sonora
9. Distichlis scoparia (Kunth) Arechav. - Chile, Argentina, Uruguay
10. Distichlis spicata (L.) Greene