StYP, the St genome being from Pseudoroegneria, the P genome from Agropyron, and the Y genome being of unknown origin because there are no monogenomic species that have only the Y genome. It has been suggested that it may be derived from the St genome, being modified in such a way that its chromosomes no longer pair with those of the St genome. This is still only a suggestion.
Plants perennial, with solitary spikelets, the spikelets usually crowded but sometimes very widely spaced. Glumes symmetric, membranous, the midvein often prominent. Lemmas usually evidently hairy, sometimes inconspicuously so. Paleas with coarse, widely spaced teeth on the keels, curving distally to a narrow tip.
Plants perennial. not or shortly rhizomatous. Culms 12-120(150) cm tall; lowest internode 0.8-3.4 mm thick.
Leaves 1-10 mm wide, flat to slightly convolute.
Inflorescence spikelike, 2-20 cm long, usually erect if less than 9 cm long, often curved to drooping when longer; lrachis tough, terminating in ??owest internode at least twice as long as the middle internodes; middle internodes usually 1-10 mm long and 1/3-1/2 as long as the adjoining spikelet, sometimes, especially in plants growing in the shade, internodes to 40 mm long (and inflorescence with few nodes, sometimes as few as two or three); disarticulation below the florets.
Spikelets solitary, tangential, 7-19 mm long, usually not or only shortly greater than (0.3 mm) pedicellate, pedicels to 1.3 mm in plants with few, widely spaced nodes.
Glumes lanceolate to ovate, symmetric, membranous, often hairy, 3-10 mm long, subequal or the distal glume longer.
Lemmas lanceolate, hairy, hairs sometimes very only about 0.1 mm long and concentrated on the distal half of the lemmas, tips acute to awned, awns shorter than to less than twice as long as the lemma body, straight. Paleas subequal to the lemmas, keels with coarse, widely spaced teeth, curving slightly to the narrow tip, intercostal region retuse. Lodicules not lobed, sometimes ciliate. Anthers 0.5-3.2 mm long, yellow to black.
There are approximately 30 species in Kengyilia. Several species have varieties which brings the number to around 50 taxa. These numbers come from the listing at http://www.tropicos.org/
Kengyilia grows at high elevations on the Tibetan Plateau and adjacent regions of Central Asia.
In the past, Kengyilia was included in Elymus or Roegneria. Many herbaria probably still have specimens of Kengyilia filed under those names.
Kengyilia gobicola Yen & Yang
The biggest problem is that the genus is hard to reach and, for that reason, poorly represented in herbaria.
Baum, B.R., J.L. Yang, and C. Yen. 1995. Taxonomic separation of Kengyilia (Poaceae: Triticeae) in relation to nearest related Roegneria, Elymus and Agropyron. Plant Systematics and Evolution 194: 123-132.
Pi, Jia and Shu Cao. 2006. Kengyilia, pp. 431-437 in Wu, ZY, P.H. Raven and DY Hong (eds). Flora of China, vol. 22. Science Press (Beijing) and Missouri Botanical Garden, St. Louis, Missouri, U.S.A.
Yang, J.L., C. Yen, and B.R. Baum. 1992. Kengyilia: synopsis and a key to species. Hereditas 116: 25-28.