Trichome micromorphology in drupe of Amygdalus L. (Rosaceae) from Iran

For delimitation of species and systematic resolution, pericarp indumentum in drupes of 17 species and two hybrids of the genus Amygdalus L., representing two subgenera and two sections distributed in Iran, were studied using scanning electron microscopy (SEM) in order to assess whether in this genus, pericarp micromorphological characters are of taxonomic value. The pericarp indumentum type is velutinous with different density of trichomes. Glabrous pericarp was observed solely in A. reticulata Runemark ex Khatamsaz. All trichomes are simple. Two basic types of trichomes were distinguished on the surface of the pericarp: tubular and flattened. Among these, tubular trichomes are more frequent than other trichomes in most species except for A. kotschyi Boiss. et Hohen., A. eburnea Spach, A. spinosissima Bge. subsp. spinosissima and A. lycioides Spach var. lycioides. Density of trichomes was variable among the studied taxa. In the first subgenus (subgen. Amygdalus) with two sections, there was enough difference between sections. While density of trichomes in sect. Spartioides Spach was very low, most of species in the another section, sect. Amygdalus showed dense pericarp indumentum. Regarding density, the second subgenus, subgen. Dodecandra (Spach) Browicz showed dense indumentum. Two hybrids studied, A.´keredjensis Browicz and A.´kamiaranensis Khatamsaz et Assadi showed different pericarp indumenta, dense and sparse respectively. In conclusion, micromorphological investigation of pericarp indumentum in drupes is a useful tool for distinguishing taxa in some cases, especially those of the two sections in the first subgenus in Amygdalus

New chromosome number and unreduced pollen formation in Achillea species (Asteraceae)

Cytological studies were performed in 14 populations of 8 Achillea species growing in Iran. A. eriophora, A. tenuifolia, A. oxyodonta, A. talagonica and A. biebersteinii showed 2n = 2x = 18 chromosome number, A. wilhelmsii and A. vermicularis showed 2n = 4x = 36 and A. millefolium showed 2n = 6x = 54 chromosome number. The chromosome numbers of A. eriophora and A. talagonica are new to science and new polyploidy levels are reported for A. tenuifoli and A. wilhelmsii. Tetraploid and hexaploid species, they formed only bivalents in metaphase of meiosis-I showing diplontic behavior possibly due to allopolyploid nature of the species studied and the presence of control over pairing among homologous chromosomes. Multipolar cells were observed almost in all populations and species studied leading to the formation of abnormal tetrads and pollen grains as well as unreduced (2n) pollen formation

Pollen morphology of the genus Pyrus (Rosaceae) in Iran

In this study, pollen morphological characters of nine species of the genus Pyrus L. belonging to four sections, Argyromalon, Pashia, Pyrus and Xeropyrenia were examined by light (LM) and scanning electron (SEM) microscope. Regarding pollen shape, two forms can be recognized in the same specimen: the first form ranges from prolate- spheroidal, subprolate to prolate, while the second form includes triangular, trilobate and circular shapes, the apertures structure usually consists of three ectocolpi and three endopores. colpi occupy 85- 91% of length of pollen, often arranged meridionally but also parallel pattern can be recognized, endopore is located in the middle of colpi. Regarding sculpturing of the exine in proximal face, striate sculpturing is observed that according to some characters such as degree of slope of ridges, percentage of ridges and perforations, diameter of perforations is subdivided to four main types. Results of pollen grain fertility studies in the genus showed high percentage of fertility among studied species except in one species

Pollen morphology of Senecio L. and Iranecio B. Nord. (Asteraceae: Senecioneae) in Iran

The genus Senecio L. is one of the largest genera in the family Asteraceae. The number of taxa included in this genus is 1250. Pollen morphology has proved useful in the systematics of Asteraceae as well as in that of some of its genera and species. The pollen morphology of 16 taxa of the genus Senecio and Iranecio was investigated in detail by scanning electron microscopy (SEM). Examination showed pollen grains to be isopolar and radiosymmetric, prolate spheroidal. The close relationships are observed between the species of the section Quadridentati and the genus Iranecio. The species of the section Jacobaea showed a palynological overlap with the section Senecio. The results indicate that the palynological characters of the genus Senecio are valuable for taxonomic applications and are useful for classification

Contemporary interspecific hybridization between Dracocephalum kotschyi and Dracocephalum oligadenium (Lamiaceae) : evidence from morphological, anatomical and molecular data

Dracocephalum is the second largest genus in the family Lamiaceae with about 186 species. These species are native in temperate regions of the Northern Hemisphere and occur in the territory of the extra-tropical Asia and Europe. Eight Dracocephalum species reported in Iran; these are mainly growing in the northern and central parts of the country belonging to the Irano-Turanian phytogeographical region. Dracocephalum kotschyi is an important medicinal plant .in the country. At the same time, taxonomic position of Dracocephalum oligadenium is a challenging issue. In this work morphological, anatomical and Inter Simple Sequence Repeat (ISSR) markers were used to identify these species in Iran. MDS plot based on morphological and anatomical characters, furthermore, PCoA and MST plot based on ISSR data of species revealed hybridization between D. oligadenium and D. kotschyi

New taxa of Cousinia Cass., Sect. Stenocephalae Bunge (Asteraceae) from Iran

Six new species of genus Cousinia, sect. Stenocephalae (Asteraceae) including Cousinia ginuae, C. shahuensis from Kurdestan region, C. minuticapitata, C. touchalensis, C. kandavanensis from Tehran region and C. golestanica from Golestan region were described and illustrated. These species which are endemic to Iran are placed in accordance with some characters such as the number of flowers (up to 20), shape of head, decurrent leaves (short- or longly decurrent) and their habitat. Comments are also presented about their habitats and geographic distribution as well

New records from the genus Cousinia Cass. to the flora of Iran

Three new records of the genus Cousinia Cass. including C. hohenackeri, C. chlorocephala and C. lomakini were reported for the first time from Iran. These species have been reported from Iran, Armenia, Transcaucasus and Talesh. According to Flora of U.S.S.R., C. chlorocephala is reported from north part of Iran, however, to this date no specimen of the species has been collected form mentioned area. These species were recognized from their close species via some characters such as flower number, discolor leaves, complete to more or less deccurent leaves and shape of bracts. Photographs and distribution map of the species is presented as well

Cousinia aligudarzensis (Asteraceae), a New Species of Section Cynaroides Bunge from Iran

Volume: 17Start Page: 145End Page: 14

Leaf anatomical studies on selected species of Scrophularia L. (Scrophulariaceae) in Iran

In this survey, anatomical characteristics of leaves in 35 populations belonging to 18 taxa of Scrophularia have been studied. Among 39 quantitative and qualitative anatomical characters, some have more suitable taxonomic value for differentiation of taxa, such as blade thickness, thickness of upper and lower cuticle of midrib, length of upper and lower palisade parenchyma of blade, thickness of lower epidermis wall of midrib, thickness of upper and lower epidermis of blade, rows of spongy parenchyma of blade, upper collenchyma type of midrib and the presence of idioblast. Finally, comparison of the results of the current study together with Grau’s (1981) results confirm the validity of 4 groups out of the 12 groups which he had introduced. As for the remaining groups, no noticeable concordance was found

Anatomy of peduncle in species of Scrophularia L. (Scrophulariaceae) in Iran

The peduncle anatomy in 35 populations, which belonged to 18 taxa of Scrophularia L., were studied. Am-ong 37 quantitative and qualitative characters related to peduncle anatomy, several traits showed more taxonomic value for taxa delimitation, including presence of palisade parenchyma and the number of its layers, the presence of phloem fiber, the presence of bundle sheath, the presence of lamellar collenchyma at ridge location and the number of its layers, the dimensions of cross section, thickness of vascular bundle, the dimensions of pith parenchyma, thickness of xylem, thickness of parenchymatous part and thickness of lamellar collenchyma at ridge location. Finally, in comparison with the results obtained by Grau (1981), in which 12 groups have been introduced, the current study confirms the validity of 3 groups. However, for the remaining groups, no noticeable concordance was found