特徵描述
作者
KAO, MUH-TSUEN
型態特徵
Perennial or annual herbs, rarely suffrutescent, caulescent or acaulescent; roots often thick,tuberous or fusiform; stems erect or creeping, usually fistulose or solid. Leaves alternate, simple or prominently divided and compound, the upper petioles frequently embracing young inflorescence with a dilated sheath-like base. Flowers yellow, white, pink, purplish or violet, bisexual or polygamous, in simple or compound umbels, sometimes capitate; calyx 5-toothed; petals 5, valvate or slightly imbricate in bud, free, deciduous, often incurved at apex; stamens 5, alternate with petals. the filaments filiform, incurved in bud; ovary inferior, bilocular; styles 2, often accrescent, usually with stylopodium; ovules solitary in each cell, pendulous. Fruit a schizocarp, bilocular, separating into 2 carpels (mericarps), these usually suspended from the top of the central column called carpophore, with 5 primary ribs and sometimes 4 intermediate or secondary ones; vittae (oil-tubes) often present; seeds with abundant endosperm and a small embryo.
屬
About 200 genera and 3,000 species distributed in the whole world. sixteen genera, about 29 species and two varieties in Taiwan.
參考文獻
- KAO, MUH-TSUEN, Flora of Taiwan, second edition 3: 1010. . (Fl. Taiwan 2nd edit.)
- Hiroe, M., 1-219. 1958.
- Ohwi, J., 667-686. 1965.
- Walker, E. H., Fl. Okinawa and southern Ryukyu Is. 789-799. 1976.
Sium 零餘子屬
作者
KAO, MUH-TSUEN
型態特徵
Stout or slender, erect, herbaceous, caulescent branching, glabrous perennials, with tuberous or fibrous roots, usually in wet places. Leaves petiolate, membranaceous, pinnate, pinnately or ternately compound; peduncle terminal or axillary; involucres and involucels with many entire or incised, often relexed bracts. Flowers white; calyx-teeth evident to obsolete; petals obovate or obcordate, with narrow inflexed apices; style short to rather slender, reflexed, the stylopodium conical or depressed. Fruit oval, oblong or suborbicular, slightly compressed laterally, the ribs distinct to narrowly corky winged. Vittae 1–3 in the interval, 2–6 on the commissure. Carpels pentagonal in cross section, the carpophore 2-cleft to the base or entire. Seeds subterete in cross section.
