Miscanthus
Miscanthus oligostachyus
silvergrass
small Japanese silver grass
40-400 cm, erect.
80-150 cm tall, 2-3 mm thick below, few together or solitary;
nodes finely pubescent.
mostly glabrous, pilose near the summits;
ligules 2-3 mm, rounded;
blades well-developed only on the cauline sheaths, 8-35 cm long, 6-25 mm wide, adaxial surfaces densely pilose basally.
not aromatic;
sheaths open;
ligules membranous, truncate, ciliate;
blades flat.
long-exserted, loose, with 2-5 erect to suberect branches;
branches 7-15 cm, densely pilose, with white or purplish-white hairs.
terminal, ovoid or corymbose panicles, with elongate rachises and numerous ascending, spikelike branches;
branches usually more than 10 cm long, with unequally pedicellate spikelet pairs, spikelets homogamous and homomorphic;
disarticulation below the glumes.
6-8 mm;
callus hairs from 1/2 as long as to equaling the spikelets, silky, white.
membranous to coriaceous;
lower glumes broadly convex to weakly 2-keeled, without raised veins;
lower florets sterile;
upper florets bisexual;
upper lemmas entire and unawned or bidentate and awned from the sinuses;
anthers 2 or 3.
6-8 mm, sparsely pilose, 2-keeled above, 2-toothed, teeth densely white-ciliate;
upper glumes equaling the lower glumes, 3-5-veined;
awns of upper lemmas (4)8-15 mm, twisted at the bases;
anthers 2.5-3 mm.
free, x = 19.
short, blunt, pilose, with fine hairs, hairs often exceeding the spikelets.
pedicels 1.5-2 mm;
longer pedicels 5-6 mm, sulcate on 1 side.
= 38.
Miscanthus
Miscanthus oligostachyus
Miscanthus is a genus of approximately 25 species. Most of the species are native to southeast Asia; a few extend into Africa. Some species hybridize with Saccharum, from which Miscanthus differs in its non-disarticulating branches and unequally pedicellate, rather than sessile-pedicellate, spikelets.
The five species found in the Flora region are all grown as ornamentals because of their large, plumose panicles and striking growth habit. They flower in late summer to fall. The differing chromosome numbers within Miscanthus sinensis and M. sacchariflorus are associated with morphological differences in Japan, but it is not known if this is true for cultivated plants.
(Discussion copyrighted by Flora of North America; reprinted with permission.)
Miscanthus oligostachyus is a native of Japanese and Korean forests that is sold as an ornamental species in the United States. It does best in regions with cool summers. Koyama (1987) recognized three subspecies of M. oligostachyus; they have not been evaluated for this treatment.
(Discussion copyrighted by Flora of North America; reprinted with permission.)
1. Callus hairs 2-4 times as long as the spikelets. | → 2 |
2. Spikelets 4-6 mm long; upper lemmas unawned or the awns not exceeding the glumes | M. sacchariflorus |
2. Spikelets 2-2.8 mm long; upper lemmas awned, the awns 9-13 mm long, exceeding the glumes | M. nepalensis |
1. Callus hairs from shorter than to twice as long as the spikelets. | → 3 |
3. Culms few together or solitary; basal leaves with reduced blades, only the cauline leaves with long blades; panicles loose, with 2-5 branches | M. oligostachyus |
3. Culms densely tufted, forming large clumps; many basal leaves with long blades; panicles usually with more than 15 branches. | → 4 |
4. Spikelets 3.5-7 mm long; blades 6-20 mm wide; rachises 1/3 – 2/3 as long as the panicles | M. sinensis |
4. Spikelets 3-3.5 mm long; blades 15-40 mm wide; rachises 3/4 – 4/5 as long as the panicles | M. floridulus |
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