StYH, the St genome being from Pseudoroegneria, H from wild barley (Hordeum) and the Y being of unknown origin. 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.
Perennial plants, usually not rhizomatous. Inflorescnce with 1-3(4) spikelets per node. Spikelets pedicellate, often with pedicels more than 0.5 mm long. Glumes rounded to shortly awned; lemmas usually long-awned, sometime unawned to shortly awned.
Plants perennial, not or shortly rhizomatous. Culms 20-200 cm tall; lower internodes 1-3.5 mm thick.
Leaf blades 1.5-15 mm wide, flat or loosely involute.
Inflorescence spikelike, 5-25 cm long; rachis tough, terminating in a spikelet; lowest internode 6-26 mm long; middle internodes 2-20 mm long; disarticulation below the florets.
Spikelets paired, solitary, or in threes, 10-25 mm long, pedicellate, pedicels 0.25-1.5 mm long; lowest spikelets slightly longer than the adjacent internode, middle spikelets 2-3 times longer than the adjacent internode.
Glumes lanceolate, widest about midlength, 3-15 mm long, from much shorter than to almost as long as the adjacent lemmas, (3)5-veined, not keeled, rounded to acuminate or awned, awns to 5 mm long. Lemmas lanceolate, 8-13 mm long, often awned, awns to 50 mm long. Palea keels coarsely toothed, curved to a narrow tip. Lodicules lobed, sometimes obscurely so, sometimes ciliate. Anthers 1-4.5 mm long.
About 10 species. Seven species are known to have the StYH genomic combination but only one species name currently has a name in Campeiostachys. This will soon be corrected by Chi Yen, Jun Liang Yang and Bernard Baum.
The majority of the species are from Central Asia, particularly western China, but the genus extends from the Baltic to Japan.
The species of Campeiostachys are currently included in Elymus by almost all taxonomists.
Campeiostachys schrenkiana (Fisch. & C.A. Mey.) Drobow
There is still is some disagreement as to whether ... kamoji and .... tsukushiensis refer to two different species or the same species.
Redinbaugh, M.G., Jones, T.A. and Zhang, Y. 2000. Ubiquity of the St chloroplast genome in St -containing Triticeae polyploids. Genome 43: 846-852 . 2000.
Dewey, D.R. 1980a. Cytogenetics of Agropyron drobovii and five of its interspecific hybrids. Bot. Gaz. 141:469-478.
Lu , BR., and von Bothmer, R. 1990a. Intergeneric hybridization between Hordeum and Asiatic Elymus . Hereditas 112: 109-116.
Lu, B.R., C. Yen, and J.L. Yang. 1990. Cytological and morphological studies of Agropyron tsukushiense var. transiens of Japan, Roegneria kamoji of China and their artificial hybrids. Acta Botanica Yunnanica 13:237-246.
Lu, B.R., J.L. Yang, and J. Flink. 1990. Biosystematic studies among Roegneria pendulina, R. ciliaris, and R. kamoji of the tribe Triticeae, Gramineae. Acta Botanica Yunnanica 12:161-171.
Yen, C. and J.L. Yang. (in prep.) Campeiostachys. Manuscript.