中文摘要：

虾须草属Sheareria（菊科Compositae）是我国特有的单型属。国内学者将其置于向日葵族Helianthereae米勒菊亚族Milleriinae,而Robinson和Nesom则认为该属应归属于紫菀族Astereae。我们比较该属与向日葵族、紫菀族代表植物种类的微形态学、解剖学和细胞学特征。虾须草S.nana舌片近轴面细胞为线形,具横向条纹,细胞中央纵向隆起,与紫菀族代表种相同或相近,而与向日葵族的代表种中的细胞近圆形、表面具乳突存在显著区别。在舌状花子房壁横切面上维管束（肋）间部分的结构上,5种向日葵族植物具有如下共同特征：子房壁含3–4层结构,即表皮、下皮层、小细胞区,有的还有薄壁细胞层;表皮与下皮层细胞大小和形态一致,排列整齐。虾须草与5种紫菀族植物的子房壁均只由表皮和薄壁组织组成。虾须草为二倍体,核型公式为2n=2x=18sm。虾须草与紫菀族的染色体基数均为x=9,而和向日葵族普遍存在的染色体基数x=10不同。所有的证据都表明虾须草属应置于紫菀族,而不是向日葵族中。

英文摘要：

Sheareria S. Moore is a monotypic genus endemic to China, distributed from east to south and southwest China. This genus has been classified within the subtribe Milleriinae of the Heliantheae by the Chinese taxonomists, while Robinson and Nesom placed it in the Astereae. In the present study, we compared micromorphology, anatomy and chromosome numbers of this genus and representative species from the two tribes. The adaxial surfaces of the ligules of the only species in this genus, S. nana, have linear epidermal cell with transverse stripes and a longitudinal median promontory-like protrusion, which are identical or similar to those of the repre- sentative species of the Astereae. However, in the representative species of the Heliantheae, these cells are subround and papillose. Interfascicular parts of the cross-section of ovary walls in five species of the Heliantheae comprise 3-4 layers, including epidermis, hypodermis, small cell region and/or parenchyma tissue, and the epi- dermal cells are identical in size, shape and orderly arrangement to the hypodermal cells. In contrast, only two layers （epidermis and parenchyma tissue） were recovered in S. nana and five species of the tribe Astereae. The karyotype ofS. nana is 2n=2x=18sm with x=9, a common basic number in the Astereae, but different from x=10 of the Heliantheae. All of these results together support the tribal delimitation of Sheareria within the Astereae, rather than in the Heliantheae.