印度沙穗的花粉量限制在降低種子產量中所扮演的角色

Pollen Limitation in Eremostachys superba Royle ex Benth. (Labiatae) and its Role in Loss of Seed Production

瀕臨絕種的印度沙穗（唇形科）在自然環境下有性繁殖低於5%，而只以無性繁殖得以存續。經授粉生物學研究，得知自然環境下因授粉者限制了有性繁殖，故增加花的數量可補強授粉者之限制。觀察在原地及移地下比較昆蟲造訪及其結實，發現雖然移地下使昆蟲不斷造訪，卻只結實38%，表示自株授粉會減低受妊。由結果表示印度沙穗欠缺有性繁殖乃部份受到花粉量之限制。

The critically endangered Eremostachys superba Royle ex Benth. shows almost negligible sexual reproduction under natural conditions (<= 5%) and survives only vegetatively. Investigations on the role of pollination biology in the loss of sexual reproduction revealed a pollinator limitation in the natural habitat. Increased floral attractiveness was provided to counteract this pollinator limitation syndrome by increasing flower density. Observations were made on insect visits and resultant seed set in the ex situ plants and compared with that observed under in situ conditions. Infinite pollinators visited ex situ flowers but affected only 38% seed set. indicating a reduced fertilization due to geitonogamous pollination. These results suggested that lack of sexual reproduction in E. superba was partly due to pollen limitation.