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.

Ischaemum 鴨嘴草屬

作者

HSU, Chien-Chang

型態特徵

Annuals or perennials; culms solid. Leaf blade lanceolate or linear, sometimes with a pseudo-petiole. Inflorescence of 2 to several spike-like racemes, more or less digitately arranged, if only 2 racemes present, then usually closely appressed, at first sight appearing as a single racme. Spikelets dorsally compressed, 2-flowered, sometimes 1-flowered, in alternate pairs, one sessile, other pedicelate. Pedicelate spikelet falling entire from pedicel, callus blunt, or usually stipe-like and bearded. Spikelets sessile, arranged in front, all pedicelate spikelets behind, sometimes pedicels very short; lower glume oblong or lanceolate, convex, often hardened in lower half, often tuberculate or transversely rugose, often winged towards apex; entire or a 2-lobed, numerous-nerved, nerves of hardened lower glume only distinct near top, margins inrolled or inflexed; upper glume narrower, often longer, boat shaped, often keeled, acute, muticous or with short awn; lower lemma shorter than lower glume, ovate-oblong, apex narrowed, thinly membranaceous; lower palea nearly as long, oblong; stamens 3, or reduced into staminodes; upper lemma well-developed, convex, hyaline, entire or 2-fid and awned from sinus, awn short or long, nerves 3-5 upper palea 2-nerved; stamens 3; styles 2, free, stigmas plumose. Caryopsis oblong.