| # The grass genera of the world |

L. Watson, T.D. Macfarlane, and M.J. Dallwitz

### Kengyilia Yen & J.L Yang

Named for Yi-Li Keng, expert on Triticeae.

Habit, vegetative morphology. Perennial; caespitose. Culms 40–70 cm high (erect or geniculate from the lowest node); herbaceous; unbranched above; 2–3 noded. Culm nodes glabrous. Young shoots intravaginal. Leaves not basally aggregated. Sheath margins free. Leaf blades linear; narrow; about 3–6 mm wide ((6-)7–19 cm long); flat, or rolled, or acicular (? - K. gobicola ‘has short, rodlike leaves that form tubelike structures’, while those of K. mutica are flat to involute); not pseudopetiolate; without cross venation; persistent. Ligule an unfringed membrane; truncate; 0.5–1 mm long.

Reproductive organization. Plants bisexual, all with bisexual spikelets; with hermaphrodite florets.

Inflorescence. Inflorescence a single spike ((5–12 cm long, 4–8 mm wide, erect or slightly curved, the densely pilose internodes 3–10 mm long, decreasing in length acropetally); espatheate; not comprising ‘partial inflorescences’ and foliar organs. Spikelet-bearing axes persistent. Spikelets seemingly solitary; probably not secund; probably distichous; sessile.

Female-fertile spikelets. Spikelets 11–20 mm long; ovate; yellow-green or green to purpling; compressed laterally; disarticulating above the glumes; disarticulating between the florets (? - the rachilla articulated). Rachilla prolonged beyond the uppermost female-fertile floret; hairy (puberulent); the rachilla extension with incomplete florets. Hairy callus present. Callus short.

Glumes two; more or less equal; shorter than the spikelets; shorter than the adjacent lemmas (K. mutica), or long relative to the adjacent lemmas (the longer glume about equalling the lowest lemma, in the illustration seen of K. gobicola); lateral to the rachis (and the spikelets borne flatwise, judging from the Yang et al. illustration of K. mutica); hairy (sometimes, on the nerves), or hairless; mostly glabrous; pointed (sometimes asymmetrically dentate); awned to awnless (muticous or mucronate); carinate, or non-carinate (the midnerve prominent in K. mutica); similar (‘herbaceous’, oblong-ovate). Lower glume 3 nerved, or 5 nerved. Upper glume 3 nerved, or 5 nerved. Spikelets with incomplete florets. The incomplete florets distal to the female-fertile florets. The distal incomplete florets merely underdeveloped; awned, or awnless. Spikelets without proximal incomplete florets.

Female-fertile florets (3–)4–7(–8). Lemmas entire; pointed to blunt; mucronate to awned. Awns 1; median; apical; non-geniculate; straight; hairy; much shorter than the body of the lemma (1–5 mm long). Awn bases not twisted. Lemmas hairy (white villous, or densely hirsute); non-carinate; without a germination flap; 5 nerved (at least in K. mutica). Palea present; relatively long (equalling or slightly shorter than the lemma); tightly clasped by the lemma; entire to apically notched (truncate, blunt or emarginate); awnless, without apical setae; 2-nerved; 2-keeled. Palea back hairy (white-pilose, in K. gobicola), or glabrous (K. mutica). Palea keels wingless; hairy (at least above). Lodicules present; 2; free; membranous; ciliate (at least in K. mutica). Stamens 3. Anthers 2–3 mm long; not penicillate. Ovary apically hairy. Styles free to their bases. Stigmas 2.

Fruit, embryo and seedling. Fruit medium sized (about 6–7 mm long); dark brown; fusiform; hairy; with hairs confined to a terminal tuft. Hilum long-linear. Embryo small.

Cytology. Chromosome base number, x = 7. 2n = 42. 6 ploid. Haplomic genome content P, S, and Y (? - L.W. being insufficiently knowledgeable about genomic analysis to interpret the garbled description of Yen and Yang, 1990).

Classification. Watson & Dallwitz (1994): Pooideae; Triticodae; Triticeae. Soreng et al. (2015): Pooideae; Triticodae; Triticeae; Hordeinae. 2 species (K. gobicola, K. mutica).

Distribution, phytogeography, ecology. Gobi Desert and Quinghai Province, China.

Xerophytic; species of open habitats. In dry, stony ground at high elevation.

References, etc. Morphological/taxonomic: Yen and Yang (1990), Yang et al. 1995.

Special comments. Based on the very poor original generic description and illustrations of K. gobicola, with no information on spikelet orientation, lodicules, fruit form, etc. (Yen and Yang 1990), supplemented by the brief illustrated description of K. mutica by Yang et al. (1995). Anatomical data wanting.

Illustrations. • Kengyilia guidenensis: Yen, Yang and Baum (1995), Novon 5.

We advise against extracting comparative information from the descriptions. This is much more easily achieved using the DELTA data files or the interactive key, which allows access to the character list, illustrations, full and partial descriptions, diagnostic descriptions, differences and similarities between taxa, lists of taxa exhibiting or lacking specified attributes, distributions of character states within any set of taxa, geographical distribution, and classifications. See also Guidelines for using data taken from Web publications.

Cite this publication as: ‘Watson, L., Macfarlane, T.D., and Dallwitz, M.J. 1992 onwards. The grass genera of the world: descriptions, illustrations, identification, and information retrieval; including synonyms, morphology, anatomy, physiology, phytochemistry, cytology, classification, pathogens, world and local distribution, and references. Version: 15th June 2025. delta-intkey.com’.

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