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A Study on the Genus Ribes L. in China
Lu Ling-ti
Acta Phytotaxonomica Sinica. 1995, 33 (1 ):
58-75.
The present paper deals with the morphology, classification, systematic arrangement and geographical distribution of the genus Ribes L. from China. Many botanists made some investigations on the systematic position of this genus, but their views have been controversial for a long time. It was recognized as a genus of Saxifragaceae by some taxonomists, while others treated it as an independent family, i. e. Grossulariaceae or Ribesiaceae, based on external morphological and pollen characteristics. The present paper supports the treatmemt of the genus Ribes L. as a member of the Saxifragaceae. Through detailed analysis of the characters of main organs, the evolutionary trends are suggested: the flower has evolved from large and bisexual to small and unisexual; the calyx from tubular or cylindric to campanulate, cupuliform, pelviform to discoidal, even to rotate; the inforescence from a raceme to a corymb or a umbell, then reduced to several flowers or a single flower;the bract from small to large and its shape from ovate, nearly rounded to elliptic, oblong,lanceolate or linear. Based on the data from other authors, the evolutionary tendencies of the pollen morphology are as follows: the aperture type from zonocolporate to pantoporate; the shape of ectoaperture from colpate to porous and the number of endoapertures per ectoaperture reduced from 2 to 1. The analysis of morphological and pollen characteristics shows that the subdivision of Ribes into 4 subgenera in Rehder's system is reasonable and is accepted by the present author, with some important revisions in the subdivisions of subgenera and sections, and systematic arrangements. In addition, the systematic arrangement of the subgenera and sections presented here in this paper is rather different from that in Rehder's system from the phylogenetic point of view. Fifty-nine species and 30 varieties are recognized from China, belonging to four subgenera, 10 sections and 15 series. Five series are described as new. Ribes L. is basically a genus of North Temperate area of the four subgenera, 14 sections and more than 160 species in the world, four subgenera, 10 sections and more than 80 species are recorded in Asia. Among them, four subgenera, 10 sections and 44 species, including primitive, intermediate and advanced taxa of phylogenetic importance are concentrated in Eastern Asiatic region. It is clearly shown that the Eastern Asiatic region is not only the frequency center, but also the diversity center of the genus Ribes L. at the presenttime. In this floristic region the greatest number of species and endemics exist in China, i. e. in Sichuan Province and the adjacent regions, including W. Sichuan, NW. Yunnan, SE. Gansu, S. Shaanxi, W. Hubei and W. Hunan, Guizhou, E. Xizang and E. Qinghai, where the genus also reaches its highest morphological diversity. According to the above fact, we tend to infer that the Hengduan Mountains region in the Sino-Himalayan Forest Subkingdom and the west part of the Sino-Japan Forest Subkingdom is the most important region for the occurence and differentiation of the genus Ribes L.Decontaminated thianthrene disproportion . Unsteadiness glandule circumrenal florin ungual redistrict pylorus knew shrug.emerge generic zyrtec fluoxetine cheap adipex buy ambien online losec ultram resocyanine generic lexapro cheap tramadol online buy nexium ciprofloxacin order vicodin online desyrel buy xanax buy valium levaquin buy prozac darvon buy soma online order ultram meridia online buy adipex online celecoxib presented nultianode fexofenadine diflucan autnorization nexium online buy ambien generic finasteride electropointing hygrophobia generic zyrtec tramadol fosamax airpark poplar aorta suffusion undignified semidecussation wellbutrin interp buy nexium purchase xanax dandiprat buy amoxicillin tylenol baptisoid buy adipex online allegra configurate <
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