To clarify the pollen morphology and the taxonomical status of Tibetia liangshanensis in Tibetia, a small genus endemic in the Hengduan Mountains of SW China, we re-examined the pollen morphology of all species of Tibetia (except for a plausible species, T.forrestii) using SEM in this study- The pollen data for T liangshanensis was corrected and the others ( T. himalaica, T. yunnanensis, T. tongolensis and T. yadongensis) were confirmed. The shapes of Tibetia'S pollen grains are spheroidal or subprolate with perforate surfaces. Two types of pollen grains were found (i. e. , 3-colporate and 4-colporate) , corresponding to two sections recognized in this genus. The results showed that the pollen grain of T. liangshanensis is 4-colporate, However, it was reported as 3-colporate pollens andrntreated as a synonym of T.forrestii. Morphologically, the two species are very distinct with T. liangshanensis in Waving leaflets 13-17, stipules free and corolla purple, while T.forrestii with leaflets 7-9, stipules connate at base and corolla yellow. The epidermal characters of the two species are also distinguished under SEM. Therefore, we suggested that T. liangshanensis should regain its taxonomical status at the species level.%为澄清我国西南横断山区特有属高山豆属(Tibetia)中凉山高山豆(T.liangshanensis)的花粉粒形态及其分类学地位,用电子显微镜重新扫描了本属的花粉粒.报道了除一个可疑种中甸高山豆(T.forrestii)外所有5个种的花粉形态,即高山豆(T.himalaica),云南高山豆(T.yunnanensis),凉山高山豆(T.liangshanensis),黄花高山豆(T.tongolensis)和亚东高山豆(T.yadongensis).结果纠正了凉山高山豆的花粉粒形态,而另外4个种的花粉粒与之前的研究基本一致,仅在形状和大小上稍有差别.本属的花粉粒呈圆球形或近长球形,表面有穿孔凹陷,3-孔沟和4-孔沟两种花粉类型与高山豆属分为两个组相吻合.但我们发现凉山高山豆的花粉是4-孔沟类型,而不是之前报道的3-孔沟类型.另外,凉山高山豆与中甸高山豆的形态差异明显,凉山高山豆茎长,小叶13 ～ 17片,托叶分离,花冠紫色;而中旬高山豆茎短,小叶7～9片,托叶基部合生,花冠黄色,叶片下表皮细胞形态差异明显,因此我们认为应该将凉山高山豆独立作为一个种,而不是作为中甸高山豆的异名.
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