茭白外部形態及其花器構造之研究

Studies on the Vegetative Morphology and Floral Structure of Coba (Zizania latifolia Turcz.)

臺灣現有之茭白栽培品種有青殼、白殼及赤殼三種，青殼品種在臺灣南部地區於6~10月間陸續開花，花序為由多數小穗狀花序集合而成之大形圓錐花序，雌雄同株異花，雌花主要著生於花序上部之小穗，雄花則以著生於下部之小穗為主，中間部位之小花穗混生約同數之雌花與雄花，雌花之形狀為披針形，外稃之芒長，尖端略帶紫色，花柱白色，雄花呈狹橢圓形，外稃之芒甚短或無，尖端亦略帶紫色，雄蕊六枚，呈淡黃色，花粉粒近球形，淡黃色，染色體數為2n=34。

Coba (Zizania latifolia Turcz.) cultivars, Green-shell, White-shell and Red-shell, are commonly grown in Taiwan. Green-shell, which is popular in Southern Taiwan, was used in the present study of vegetative morphology and floral structure. This cultivar flowers continuously from early June to late October in Southern Taiwan. The plant is monoecious, and the inflorescence, consists of approximately 2200 spikelets. Most of female flowers are located in upper parts of inflorescence. Whereas, most of male flowers are concentrated in lower parts. There is almost equal number of male and female flowers in the middle part of inflorescence. The female flower is lanceolate and has long awn in the lemma. Its pistil is split and has two white color and feathery stigmas. The male flower is long oblong and has six pale yellow stamens. Its lemma may or may not have very short awn. Both male and female flowers have purple color in the tip of awn. The pollen grains are nearly round and pale yellow color. The chromosome number is 2n=34.