唐松草属六新种

Six new species of Thalictrum(Ranunculaceae)from China

关键词:  毛茛科, 唐松草属, 新种, 中国

Key words:  Ranunculaceae, Thalictrum, new species, China

摘要:

描述了毛茛科唐松草属六新种:(1)大关唐松草,发现自云南东北部,与多枝唐松草甚为近缘,区别为其小叶较厚,较大,多呈卵形或宽卵形,心皮花柱较短,稍向后弯曲,瘦果呈新月形。(2)宽柱唐松草,发现自甘肃南部,其特征为心皮花柱扁平,近长圆形,腹面无柱头或柱头组织,据此特征可与此属中国其他种区别。(3)六脉萼唐松草,发现自四川中部,与白茎唐松草近缘,区别为其茎和小叶有毛,萼片具六条脉,一些雄蕊的花药败育,子房被短柔毛,柱头无翅。(4)吉隆唐松草,发现自西藏南部,与白茎唐松草甚为近缘,区别为小托叶卵形、急尖,复单歧聚伞花序一条顶生,无侧生者,雄蕊花药呈狭长圆形,顶端钝,无短尖头。(5)螺柱唐松草,发现自云南西北部,可能与白茎唐松草有亲缘关系,区别为其萼片具1条脉,花有4～5枚雄蕊,心皮花柱顶部螺旋状弯曲,柱头不明显。(6)札达唐松草,发现自西藏西南部,与多叶唐松草近缘,区别为其小叶顶端急尖,边缘具尖牙齿,聚伞圆锥花序具少数分枝和少数花,萼片狭卵形,花药狭长圆形。

Abstract:

Six species of the genus Thalictum (Ranunculaceae)are described as new from China:(1) Thalictrum daguanense, described from north-eastern Yunnan Province, is closely related to T. ramosum Boivin, differing from the latter in its thicker, larger and mostly ovate leaflets, shorter and slightly recurved carpel styles, and lunate achene.(2)T. latistylum, described from southern Gansu Province, is charcterized by its flattend suboblong carpel style ada-xially without stigma or any stigmatic tissue, and by this unique character can be distinguished from other chinese species of Thalictrum.(3)T. sexnervisepalum, described from central Sichuan Province, is related to T. leuconotum Franch., differing from the latter in its hairy stem and laeflets, 6-nerved sepals, some stamens with abortive anthers, puberulous ovariies, and not winged stigmas.(4)T. jilongense, described from southern Xizang Zizhiqu, is closely related to T. leuconotum Franch., differing from the latter in its ovate, acute stipels, thyrses without lateral compound monochasia, and narrowly oblong and not mucronate anthers.(5)T. spiristylum, described from northwestern Yunnan Provice,is probably related to T. leuconotum Franch., differing from the latter in its 1-nerved sepals, 4-5-staminate flower, spiraly curved style apex, and inconspicuous stigma.(6)T. zhadaense, described from south-western Xizang Zizhiqu, is related to T. foliolosum DC., differing from the latter in its acute and acutely dentate leaflets, few-branched and few-flowered thyreses, narrow-ovate sepals and narrow-oblong anthers.