鳞茎

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植物学上指某些种子植物,尤其是多年生的单子叶植物(参阅cotyledon)的处於休眠阶段的变态茎。鳞茎包括较大且通常为球形的地下苞芽和伸出地面的短茎,膜质或肉质的叶互相重叠,从短茎上生出。鳞茎的肉质叶用以储存食物,可使植株於缺水时(如冬季或乾旱时)休眠,当条件有利时又恢复生机。鳞茎主要有两种类型,一种类型以洋葱为代表,肉质叶外覆以纸样的薄膜以资保护;另一种类型见於真正的百合,贮藏叶裸露,无纸样薄膜覆盖,外观似由许多有棱角的鳞片构成。许多普通观赏植物,如水仙、郁金香和风信子,能於具备有利的生长条件时在早春迅速开花。另一些具鳞茎的植物,如百合,在夏天开花;或如秋水仙,在秋天开花。藏红花属和唐菖蒲属的固体球茎以及某些鸢尾属的长形根茎都不是鳞茎。

bulb

In botany, the resting stage of certain seed plants, particularly perennial monocotyledons (see cotyledon), consisting of a relatively large, usually globe-shaped, underground bud with membranous or fleshy overlapping leaves arising from a short stem. The fleshy leaves function as food reserves that enable a plant to lie dormant when water is unavailable (during winter or drought) and to resume active growth when favorable conditions again prevail. There are two main types. One, typified by the onion, has a thin papery covering protecting its fleshy leaves. The other, the scaly bulb, as seen in true lilies, has naked storage leaves, with no papery covering, making the bulb appear to consist of angular scales. Bulbs enable many common ornamentals, such as narcissus, tulip, and hyacinth, to flower rapidly in early spring when growing conditions are favorable. Other bulb-producing plants bloom in the summer (e.g., lilies) or fall (e.g., the autumn crocus). The solid corms of the crocus and gladiolus, and the elongated rhizomes of some irises are not bulbs.

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