The characteristics of the seeds of 7 annual and perennial species of Trifolium, Lotoidea section, in Iran were investigated by means of Scanning Electron Microscopy (SEM) and a stereomicroscope. Contrary to Zohary's belief who maintained that the micromorphology of the Trifolium's seed played no role in taxonomy, the results revealed that such characteristics can play a determining role in differentiating such species and distinguishing them from one another. The results of the micromorphologic study of the seed confirmed the morphological results of the species of the Lotoidea section to a great extent, but was involved in the separation and differentiation of the two species of T. repens and T. nigrescens. In general, the characteristics of the species' seeds proved quite effective in determining their phenetic relationship. Among the characteristics studied in the present research, mention can be made of seed shape, hilum shape, seed sculpture and seed length and width (L/W ratio). The results demonstrated that the characteristics of seed length and hilum shape showed the greatest diversity in the species. The longest seed length was that of the species T. radicosum and the shortest that of T. repens. The spindle shape of the hilum was an exclusive characteristic of T. radicosum which distinguished it more than any other characteristic from all the other species of this section. The difference in hilum shape in the two species of T. repens and T. nigrescens was an important distinctive characteristic.

ABSTRACT. Chromosome numbers in 140 accessions of 37 annual and perennial species of Trifolium L. in Iran were counted and studied here. The chromosome number of 2n=16 was documented in Trifolium radicasum in Iran. New cytotypes were found in Trifolium ambigum, T. fragiferum, T. montanum, T. nigrescens, T. stellatum and T. tumens. This study deposited more data in chromosome numbers of Trifolium to determine the genus has high diversity of ploid level. Their karotypic formula showed that the most of the chromosomes were median-, submedian-or terminal-centromeric. The smallest chromosomes were found in Sections Versicaria and Mistyllus, while the largest chromosomes were found in Sections Trifolium and Tricocephalum. Thus, Trifolium seemed to be heterogeneous with respect to morphological characters of chromosomes.

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Minuartia khorassanica is introduced and described as a new species. The species has a limited distribution in E. Iran close to the Afghanistan frontier. Minuartia afghanica Rech. f. from Afghanistan and Pakistan is morphologically related to the new species but it is not known in Iran. The most important differences between the new species and M. afghanica are mainly in the shape of sepals and leaves and pedicel length. Moreover the two species have quite distinct ranges. Minuartia lineata Bornm. is another relative of the new species differing from it mainly in reproductive characters. The new species is illustrated and compared with M. lineata based on seed and pollen grain data. An identification key to distinguish these three species is given. In addition, Minuartia litwinowii Schischk. from Turkmenistan and adjacent areas in Iran is reduced to the rank of subspecies as M. lineata subsp. litwinowii. Identification key and selected specimens are given for the two subspecies of M. lineata. The distribution map of all taxa is presented. (© 2011 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)