In the work mitotic chromosomes in root-tips of 7 species native to Sichuan Pro-

vince were examined and their karyotypes were analysed based on 7-8 cells at mitotic meta-

phase, using Levan et al.‘s (1964) nomenclature. The list of species and origin of the materials

used in this work are provided in the appendix.  The micrographs of mitotic metaphase of all

the materials are shown in Plates 1 and 2; the idiograms in Fig. 1, 1-9, and the parameters

of chromosomes are provided in Tables 1-9.  All the chromosome countings and karyotypes in

this paper are reported for the first time.

     Characteristics of the karyotypes may be summarized as follows:

     1.  2n=38 are found in all the materials except A. sichuanensis, which has 3 cytotypes, i.e,

2n=38+5B, 2n=38+lB and 2n=38+OB (Plate 2, 1-2, Fig. 1, 5-6).

     2.  The karyotypes are of two major types: the karyotype of A. flaviflora falls into 3C in

Stebbins‘s (1958, 197l) classification of karyotypes and those of all the other species into 2C.

The two types are also different from each other in the number of large and medium-sized

chromosomes pairs and morphology of the first pair of chromosomes (compare Plate 2, 5, Fig.

1, 9 with the other micrographs and idiograms).A. flaviflora with the karyotype 3C also differs

from the other species in a series of gross morphological characters: the species is of a yellow and

campanulate corolla.

     3.  The species with caespitose leaves (A. caespitosa and A. omeiensis) have essentially the

same karyotype, which is rather different from those of the species with scattered leaves. There

are two pairs of small sm chromosomes (arm ratio ≥1.90) in the former karyotype (Tables 1

and 3), but all the small chromosomes are m or sm with arm ratio <1.80 in the latter karyotypes.