When Did Grass Evolve?

The grass is a plant of the family Poaceae. It is documented in "Chinese Flora, Vol. 10 (1)". The shape of the grass is slender, glabrous, 10-25 cm in height, 0.5 mm in diameter, and white on the leaves. Small fluff.

Grass

(Gramineous plant)

Dwarf herbs, often forming dense clusters. The leaves are collected at the base, and the sheath is densely fibrous near the ground; the tongue is extremely short with short cilia; the leaves are narrow and linear, often rolled into needles, 1-6 cm long, 0.8-1.2 mm wide, and sometimes sparse above White villi with thickened edges. Spikes are individually terminal, with 1 joint at the insertion site, somewhat arcuate, long (3-) 5-8 (-10) cm, with short or glabrous margins; spikelets lanceolate, long 2.2-2.8 mm; glume membranous, as long as spikelets, sometimes purple-brown, awnless, with 1 vein; first glume is slightly asymmetric, second glume is flat; lemma membrane is transparent, about 1.5 mm in length, Apex long acuminate, pubescent on back, with -3 veins, lateral veins with white long cilia near margins; inner palate membranous, lanceolate, slightly shorter than outer palate, with 2 ridges, pubescent on spine, ridge Between hairs. Flowers and fruits are from July to September. ^[1]

Produced in Tibet,

Long spike grass (pseudo) (variant)

The main differences from the original varieties are: taller plants, 25-60 cm stalk height, about 1 mm in diameter, spikes (10-) 15-20 (-25) cm long, spikelets 2-4 mm long, spikes Shaft margins are longer pilose or glabrous; lemma is 1.6-3.0 mm. Chromosome 2n = 40 (Moffett et H., 1949). The flowering period is from July to August. ^[1]

It is produced in northwestern Yunnan; it is born in barren grassland under the altitude of 1 100m-2500m, Yunnan pine forest, riverside rock gap or river beach grassland. It is also found in northeastern India, Malaya, tropical Africa and the Americas. Type specimens are taken from tropical America. ^[1]

This variant and the original variant are often born in the same environment in Yunnan, are perennial, and there is no absolute boundary between the original variant and the original. Bor (1960) referred to M. indica (L.) Beauv. As an annual plant, and M. Kunthii Desv., Which was divided into two species for perennial plants, but it was difficult to distinguish in practice, so the latter species was used as a variant of the former species. ^[1]