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In the Iberian Peninsula and Balearic Islands pollen dimorphism was found inTeucrium fruticans L.,T. pseudochamaepitys L., andT. rotundifolium
Schreber. Generally, this dimorphism shows two sizes of pollen grains, the smaller more or less collapsed. The percentage of pollen viability is calculated. Differences in size between viable and nonviable pollen grains are similar, being about 40% inT. fruticans andT. pseudochamaepitys, and about 26% inT. rotundifolium. With regard to pollen viability, the percentage of male sterility is higher inT. fruticans, in which from male sterile (ms) plants, 100% nonviable pollen was obtained from every flower observed. InT. pseudochamaepitys andT. rotundifolium with rare exceptions, the percentage of nonviable pollen does not seem to be significant. 相似文献
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Petar D. Marin Branimir Petković Sonja Duletić 《Plant Systematics and Evolution》1994,192(3-4):199-214
Nutlet sculpturing of 23Teucrium species belonging to six sections was studied. The nutlets of analysed species were characterized by the presence of the oil glands of various density. SectionTeucrium is well defined by very densely distributed trichomes and oil glands on nutlets. Trichomes on nutlets were absent in all other species, except inT. marum from sect.Chamaedrys. Sect.Polium is a homogeneous group, distinguished from the other sections. There are some similarities of this sect. with sect.Scordium. Species of sect.Chamaedrys are heterogeneous and overlap according to the surface sculpturing characters with the other sections. The significance of nutlet microcharacters as additional taxonomical markers in the infrageneric classification of the genusTeucrium is discussed. 相似文献
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Two newCycas species from Thailand are here described.C. petraea andC. elephantipes. A noteworthy extensions of the range ofC. macrocarpa into southeastern Thailand is recorded. New taxa are illustrated, distributions of the new taxa are mapped, and a key to the species ofCycas in Thailand is provided. 相似文献
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Aristolochia dinghoui is described from southwestern Thailand. It is morphologically similar toA. harmandiana Pierre ex Lecomte, from Cambodia and Laos, and also bears some resemblance toA. philippinensis Warb. andA. sericea Blanco, both from the Philippines. A key to these four species is included, and some of their diagnostic features are listed.
Resumen Aristolochia dinghoui est décrite à partir de spécimens recueillis dans le sud-buest de la Thailande. Morphologiquement pareille à l'A. harmandiana Pierre ex Lecomte de l'Indochine, elle présente également des ressemblances avecA. philippinensis Warb. etA. sericea Blanco, des iles Philippines. Une clé est proposée pour distinguer ces quatre espèces. Les caractères diagnostiques de l'{btA. dinghoui} sont illustrés.相似文献
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The pollination syndromes ofLeonotis (Pers.)R. Br. are discussed. Ornithophily accounts for most of the nutlets set in perennialLeonotis species but in the annual species [L. nepetifolia (L.)R. Br.] autogamy prevails.Leonotis species are predominantly pollinated by a variety of sunbirds, although bees are also involved. Nectar is sucrose-dominant in perennial species but hexose-dominant in the annual. 相似文献
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Genista valsecchiae from SW Sardinia is described and illustrated as a species new to science. It is very similar toG. ephedroides and can be distinguished by morphological differences of habit and inflorescence. It typically occurs in the garigue or maquis and is widespread in SW Sardinia. 相似文献
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Renata Jurišić Grubešić Sanda Vladimir-Knežević Dario Kremer Zdenka Kalodera Jadranka Vuković 《Biologia》2007,62(2):148-156
Micromorphological investigation of the types, dimensions and distribution of characteristic trichomes in leaves and stems in Teucrium L. species (T. arduini L., T. chamaedrys L., T. flavum L., T. montanum L., T. polium L., and T. scordium L. subsp. scordioides Schreb.) distributed in Croatia was carried out as part of the taxonomical study of the genus Teucrium. Secretory types of hairs, peltate and capitate hairs were observed on the epidermis of stems and leaves of all investigated species. Non-secretory, acicular hairs were almost completely lacking on stems of T. scordium subsp. scordioides. Flagelliform hairs were not found in T. flavum and T. polium. Cladose hairs were present only in T. polium. The largest micromorphological variability was established between wild and cultivated samples of T. arduini and T. scordium subsp. scordioides, while cultivated and wild specimens of T. polium were almost identical. Differences were primarily observed in trichome dimensions and much less in micromorphological features. 相似文献
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A black limestone collected from near Kantan, Trang Province, southern Thailand, contains two species of sphinctozoan sponge which have been namedAmblysiphonella parva n. sp. andPlatythalamiella minima n. sp. The former is a cylindrical chambered sponge with an axial spongocoel and ring chambers.P. minima is an asiphonate and tabular sponge characterized by small chambers arranged in one or two layers above and beside each other. Both are the smallest known species in their respective genera. Hypercalcified sponges have not previously been reported from the Triassic of Thailand. 相似文献
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Hans R. Preisig 《Plant Systematics and Evolution》1989,164(1-4):209-214
A new species ofMallomonas, M. alphaphora (Chrysophyceae), was found in freshwater ponds in the Perth region, Western Australia. It is distinguished from other species ofMallomonas by its very distinctive scale and bristle morphology and is placed in a new section,Alphaphorae, of the genusMallomonas.
Dedicated to Prof. DrL. Geitler on the occasion of the 90th anniversary of his birthday. 相似文献
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Jalal El Oualidi Olivier Verneau Suzette Puech Jean-Yves Dubuisson 《Plant Systematics and Evolution》1999,215(1-4):49-70
A phylogenetic study based on sequence data from the complete internal transcribed spacer region (ITS) of nuclear ribosomal DNA for sect.Polium of the genusTeucrium shows both intersectional congruence and intrasectional incongruence with traditional morphological classifications. We attribute this incongruence largely to problems related to the polyploid complex studied. SectionPolium includes many poorly differentiated taxa of probable recent origin through hybridization followed by polyploidization. Both on the basis of parsimony and distance (Neighbor-Joining method) analyses,T. dunense andT. thymifolium are the species that diverge most from the sampled taxa. However, unlikeT. thymifolium, the morphology ofT. dunense is not much differentiated in relation to the other taxa. Both species are, nonetheless, the only sampled species to occupy isolated, exclusive environments and which may have undergone rapid evolution by a bottleneck effect.Teucrium dunense is found only on dunes along the Spanish and French coasts andT. thymifolium, a chasmophytic species with limited endemism, is found solely on limestone and dolomite cliffs in the low mountains in south-eastern Spain. A hypothesis is presented to explain the discrepancy between the observed comparatively large amount of ITS sequence divergence and the low morphological differentiation inT. dunense. 相似文献
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M. Sivadasan 《Plant Systematics and Evolution》1986,153(3-4):165-170
Amorphophallus nicolsonianus species nova, with cylindrical or napiform corms, is the only representative of the sect.Rapyogkos in India. All the other hitherto known species of this region have globose or depressed globose corms. The new species is related to some Indochinese species and toA. hildebrandtii (
Engl.)Engl. & Gehrm. from Madagascar. 相似文献
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Phagnalon rechingeri spec. nova from S Baluchestan (Iran) is described as a species new to science and illustrated; its relationships to other species of the genus, in particular to thePh. woodii group from S Arabia, are discussed.Dedicated to Hofrat Univ.-Prof. DrK. H. Rechinger on the occasion of his 80th birthday. 相似文献
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Summary The new species Cibirhiza spiculata Thulin & Goyder, from Acacia-Commiphora bushland on sand in the Somali National Regional State (Ogaden) of Ethiopia, is described and illustrated. Its conservation
status has been assessed. A molecular phylogenetic analysis confirms its placement in the tribe Fockeeae and indicates a position of the new species as sister to C. albersiana. The almost obsolete anther appendages, the outer corona with spreading lobes, as well as the pollinia with apparently single
pollen grains, also support its placement in Cibirhiza. However, C. spiculata differs markedly from both previously known species of this genus (C. dhofarensis in Oman and Yemen and C. albersiana in Tanzania and Zambia) by its narrowly linear, subsessile leaves and by the inner corona lobes that are curved inwards over
the gynostegium and each ending in a spinulose head. 相似文献
15.
Masatsugu Yokota Seibun Higa Hisashi Yoshioka Kei-ichi Shimabuku 《Journal of plant research》1988,101(1):1-8
Viola stoloniflora Yokota et Higa (Violaceae) is newly described from Okinawa Island, the Ryukyus. This species is characterized by the procumbent
stolons, the almost round leaf blades, the densely pilose petioles, the ebarbate white petals with violet veins, and the chromosome
number of 2n=22. The present species belongs to Sect.Nomimium, Subsect.Serpentes and is closely related to theV. iwagawai group of Sect.Nomimium, Subsect.Adnatae. 相似文献
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A third species of the until recently monotypic genusDistichochlamys (Zingiberaceae) is described from living and preserved material collected in northern Vietnam.Distichochlamys rubrostriata is distinguished from the original species,D. citrea, and the recently describedD. orlowii, on the basis of leaf, inflorescence bract, lateral staminode, and labellum characters. 相似文献
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D. J. Goyder 《Kew Bulletin》2008,63(3):467-469
Summary Tylophora tridactylata Goyder (Apocynaceae: Asclepiadoideae) is described from the Eastern Arc mountains of southern Tanzania and illustrated. Its conservation status is assessed. 相似文献
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Alberto E. Areces-Mallea 《Brittonia》1992,44(1):45-49
Leptocereus santamarinae is newly described as endemic to the dry evergreen forests of the keys and mainland coast of northeastern Cuba. Its closest
relationship appears to be withL. sylvestris, of the southeastern coastal woods of Cuba. A key to the twelve known species ofLeptocereus is provided. 相似文献
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A new species of cycad allied to theC. circinalis group,Cycas pranburiensis, is described from the southeast karst area of Thailand near Pranburi, Prachuap Khiri Khan province. It is distinguished by its short leaves with broad, coriaceous leaflets and mostly unarmed petioles, and the extended, gently curved sterile apices of the microsporophylls. The cone beetle fauna of the new species, believed to be involved in pollination, is distinct from that of other southeast Asian species ofCycas. 相似文献