特徵描述
作者
HSU, Chien-Chang
型態特徵
Annuals or perennials herbs, rather rarely with woody perennials culms (subfamily Bambusoideae); hollow or solid, septate at nodes. Perennials herbs or their branches at base usually with scales (cataphylls, transformed leaf sheaths). Leaves two-ranked, consisting of a sheath, ligule, and a blade. Axillary buds when grown out into a branch provided with a usually 2-nerved bract (prophyll) between branch and culm. Leaf blade mostly linear and not petiolate at base, rarely with broad blades and stipitate (pseudo-petiole) at base (especially in Bambusoideae); ligules membranaceous or ciliate, rarely lacking (Echinochloa), margins of sheath of leaf connate at least at base. Inflorescences usually terminal, primarily paniculate, but secondarily extremely variable and transformed into racemes, spikes, digitate umbels, etc. Flowering unit (spikelet) usually with 2 bracteoles (glumes) at base; base occasionally with an obconical blunt to very acute thickening (callus). Flowers alternatingly along a central axis (rachilla) supported by a bract (lemma) and a prophyll (palea), bisexual or occasionally unisexual. Lemma and palea when falling as a unit clasping fruit at base often with an obconical blunt to very acute thickening (also called callus). Perianth usually composed of 2 or 3 minute scales (lodicules), rarely 6, sometimes absent (e.g. in sterile or female florets). Stamens usually 3, sometimes 6 (Bambusoideae), or 1 or 2; filaments filiform; anthers 2-locular. Pistil 1, superior; ovary and single anatropous ovule completely adnate; styles 2 or 3, apical or subapical, stigmas plumose. Caryopsis with rich endosperm; embryo basal, abaxial (facing lemma), opposite to punctiform to linear adaxial hilum (facing palea).
屬
The Gramineae are one of the largest families of vascular plants with an estimated 620 genera and 10,000 species. Keng (1965) reported 201 genera and 775 species for mainland China. Hsu (1974) treated 5 subfamilies (excluding Bambusoideae), 27 tribes, 118 genera, 289 species, 1 subspecies, 39 varieties, and 8 forms in Taiwan.
The following arrangement of subfamilies, tribes and genera is that of Hsu (1978) with very few modifications. The descriptions of most genera are unchanged in this edition except that genera of the subfamily Pooideae (Festucoideae) which was mostly adopted from Clayton and Renvoize (1986). Some critical remarks were provided by Dr. J. F. Veldkamp, National Herbarium of the Netherlands, Leiden. Some line-drawings of Paniceae were drawed by Y. Fujimoto, Botanical Institute of Fujimoto, Kobe, Japan.
參考文獻
- HSU, Chien-Chang, Flora of Taiwan, second edition 5: 318. 2000. (Fl. Taiwan 2nd edit.)
- Clayton, W. D. and Renvoize, S. A., Her Majestys Stationary Office. London . 1986.
- Hsu, C. C., Taiwan Prov. Educ. Assoc. Taipei . 1975.
- Hsu, C. C., Flora of Taiwan 5: 373-783. 1978. (Fl. Taiwan)
- Koyama, T., Kodansha Ltd. Tokyo . 1987.
- Kuo, P. C., Flora Reipublicae Popularis Sinicae 9(3): . 1987. (Fl. Reip. Pop. Sin.)
- Osada, T., . 1993.
- Watson, L. and Dallwitz, M. J., CAB International, Wallingford . 1992.
Themeda 菅屬
作者
HSU, Chien-Chang
型態特徵
Perennials; culms solid, hard, glabrous. Leaf sheaths compressed-keeled; ligule short to moderately long, membranaceous; blades linear, margins rough. Inflorescence a short, compact, spike-like raceme of 7-11-spikelets; raceme shortly peduncled, enclosed in spathe, terminating in short flowering branchlets, consisting of peduncled raceme, spathe and next-lower internode, solitary or in sympodial fascicles. Spikelets in alternate pairs,one of a pair pedicelate or sessile,one sessile; uppermost pair forming a triad with terminal spikelet; spikelets dorsiventrally arranged, lowest two pairs forming a kind of involucre, staminate or empty, muticous, sessile, all or partly persistent, upper part of raceme 1-3-jointed, upper joint with triad of one sessile bisexual and two pedicelate staminate or empty spikelets, occasionally lower joints except involucre, each with one sessile bisexual and one pedicelate staminate or empty spikelet. Bisexual spikelets usually terete, glumes as long as spikelet, brown-or white-hairy at top or entirely hairy; lower glume oblong, with narrowed apex and incurved margins, chartaceous, upper glume with narrowed apex, thin membranaceous, margins involute; lower lemma shorter, thin membranaceous, nerveless; lower palea absent;. upper lemma like lower lernma and muticous, short awned or with a robust, geniculate awn; upper palea wanting or small, nerveless; styles 2, free, stigmas long, purple, exserted laterally from middle or near apex; callus of mature spikelets pungent, brownhairy. Caryopsis oblong, free between hardened glumes. Lower glume of involucral spikelets as long as spikelet, lanceolate, acute, margin narrowly incurved, winged or not, closely nerved; upper glume acute, hyaline, 3-6 nerved; lemmas, if pressent, thin membranaceous; stamens 3. Pedicelate spikelets ca. similar.
