Gramineae

禾本科

APG 4

Poaceae 禾本科

特徵描述

屬列表

標本列表

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.

Digitaria 馬唐屬

作者

LIU, Ho-Yih

型態特徵

Annuals or perennials; culms hollow or solid; erect, ascending or creeping; shoots intravaginal. Sheaths of leaf often loose from culm; ligule well-developed, membranaceous; blades linear to lanceolate,with broad base and acute tip, flat, soft. Inflorescence branched from all sides, composed of 2-numerous spike-like racemes. Spikelets crowed, alternately 2-3-together along keel, unequally pedicelatein a group, sometimes subsessile, articulate with widened tip of pedicel, dorsally compressed, linear-lanceolate to obovate, small, 2-flowered, muticous, usually equal in from and size; lower glume absent or very small, hyaline and veinless, rarely faintly 1-veined; upper glume very veriable in length, thin, hyaline and veinless, rarely faintly 1-neined; lower lemma as long as spikelet, rarely shorter, 5-9-veined; lower palea absent or very small and adnate to base of upper lemma; upper lemma as long as spikelet or slightly shorter, papery with broadly inflexed, hyaline or pale margins, densely striate and very finely tuberculate, often olive-green, brown or dark purple at maturity, glabrous; upper palea as long and of same texture, 2-veined, with inflexed margins, embraced to apex by margins of upper lemma; lodicules very small, cuneate; stamens 3; style 2, free; stigmas plumose, exserted at or near apex. Caryopsis tightly enclosed by only slightly indurate upper palea and lemma, elliptic, dorsaly compressed, hilum punctiform, embryo at most 1/2 as long as caryopsis.