1b. Dimeria ornithopoda subsp. subrobusta (Hackel) S. L. Chen & G. Y. Sheng, Fl. Reipubl. Popularis Sin. 10(2): 172. 1997.
具脊觿茅 ju ji xi mao
Dimeria ornithopoda var. subrobusta Hackel in A. Candolle & C. Candolle, Monogr. Phan. 6: 82. 1889; D. heterantha S. L. Chen & G. Y. Sheng.
Culms up to 60 cm tall. Racemes 2–5, 2–8.5(–10) cm. Spikelets (2.5–)3–3.5(–4.5) mm; lower glume slightly shorter or equal to spikelet; upper glume sharply keeled throughout, keel narrowly winged. Fl. and fr. Sep–Oct.
Mountain slopes, streams, valleys; below 1100 m. E, S, and SW China [Japan].
Three varieties have been recognized under this subspecies in China, as follows: var. subrobusta Hackel, with culms 9–60 cm tall; spikelets reddish brown or pale, 3–3.5 mm; throughout the range of the subspecies; var. nana Keng & Y. L. Yang (J. Nanjing Univ., Nat. Sci. Ed. 1980(4): 109. 1980), with culms 4–12 cm tall, 5–13-noded; spikelets yellow, 3–4 mm; from Anhui; and var. plurinodis Keng & Y. L. Yang (loc. cit.), with culms 20–60 cm tall, 8–17-noded; spikelets 2.5–3 mm; from Taiwan.
The name Dimeria heterantha is based on an aberrant specimen of D. ornithopoda. The lower lemma is a small, hyaline scale, and the upper lemma is geniculately awned as usual. The upper floret possesses a minute palea, and a third awned lemma is placed above it.