Dactylis

Dactylis
Scientific classification
Kingdom:	Plantae
(unranked):	Angiosperms
(unranked):	Monocots
(unranked):	Commelinids
Order:	Poales
Family:	Poaceae
Genus:	Dactylis L.
Species
See text

Dactylis is a genus of grasses in the subfamily Pooideae, native to Europe, Asia, and northern Africa. They are known in English as cock's-foot or cocksfoot grasses, also sometimes as orchard grasses.

Taxonomy

The genus has been treated as containing only a single species D. glomerata by many authors, treating variation in the genus at only subspecific rank within D. glomerata,^[1][2][3] but more recently, there has been a trend to accept two species,^[4] while some authors accept even more species in the genus, particularly island endemic species in Macaronesia.^[5][6][7][8]

Description

Dactylis species are perennial grasses, forming dense tussocks growing to 15–140 centimetres tall, with leaves 20–50 cm long and up to 1.5 cm broad, and distinctive tufted triangular flowerheads comprising a panicle 10–15 cm long, turning pale grey-brown at seed maturity. The spikelets are 5–9 mm long, typically containing two to five flowers. The stems have a flattened base, which distinguishes them from many other grasses.^{[2][9][10][11]}

Species

• Dactylis glomerata L. Throughout most of the range of the genus.
• Dactylis marina Borrill. Western Mediterranean region (SW Europe, NW Africa).
• Dactylis metlesicsii Schönfelder & Ludwig. Canary Islands, endemic.
• Dactylis smithii Link (syn. D. glomerata subsp. smithii (Link) Stebbins & Zohary). Canary Islands, Cape Verde, Madeira.

Cytology

The taxa show several different levels of polyploidy. Dactylis glomerata subsp. glomerata and D. glomerata subsp. hispanica are tetraploid forms with 28 chromosomes. Several of the other taxa, including D. glomerata. subsp. himalayensis (syn. D. himalayensis), D. glomerata subsp. lobata (syn. D. polygama), D. metlesicsii, and some forms of D. smithii, are diploid with 2n = 14; hexaploids with 42 chromosomes also occur rarely.^[2][6][12]

References

1. ^ Flora Europaea: Dactylis glomerata
2. ^ ^{a b c} Flora of China: Dactylis
3. ^ Wetschnig, W. (1991). Karyotype morphology of some diploid subspecies of Dactylis glomerata L. (Poaceae). Phyton (Horn, Austria) 31 (1): 35-55 fulltext
4. ^ Germplasm Resources Information Network: Species Records of Dactylis, http://www.ars-grin.gov/cgi-bin/npgs/html/taxon.pl?13114 Dactylis glomerata
5. ^ Parker, P. F. (1972). Studies in Dactylis II. Natural variation, distribution and systematics of the Dactylis smithii Link. complex in Madeira and other Atlantic islands. New Phytologist fulltext
6. ^ ^{a b} Schönfelder, P., & Ludwig, D. (1996). Dactylis metlesicsii (Poaceae), eine neue Art der Gebirgsvegetation von Tenerife, Kanarische Inseln. Willdenowia 26 (1–2): 217–223. Full text
7. ^ Banco de Datos de Biodiversidad de Canarios Lista de especies silvestres de Canarias: hongos, plantas y animales terrestres
8. ^ Flora of Pakistan: Dactylis
9. ^ Kew GrassBase: Dactylis
10. ^ Interactive Flora of NW Europe Dactylis glomerata (Cock's-foot)
11. ^ FAO factsheet: Dactylis glomerata
12. ^ Míka, V., Kohoutek, A., & Odstrèilová, V. (2002). Characteristics of important diploid and tetraploid subspecies of Dactylis from point of view of the forage crop production. Rostlinná Výroba 48 (6): 243–248. Full text