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1.
Hans V. Hansen 《Nordic Journal of Botany》1990,9(5):469-485
The phylogeny of the Gerbera-complex (Compositae, tribe Mutisieae, subtribe Mutisiinae) is discussed with the use of cladistics. 14 OTUs are accepted, viz. 1. Trichocline s. str., 2. Lulia , 3. Trichocline spathulata ("Amblysperma") , 4. Gerbera hieracioides, 5. Chaptalia , 6. Leibnitzia , 7. Uechtritzia , 8. Perdicium , 9. Gerbera sect. Gerbera , 10. Gerbera sect. Parva , 11. Gerbera sect. Lasiopus , 12. Gerbera sect. Piloselloides , 13. Gerbera sect. Pseudoseris , and 14. Gerbera sect. Isanthus. The work is mainly based on SEM-studies. The paper discusses the phylogenetic and taxonomic implications of the presented consensus-tree. It is proposed to rank the Gerbera-complex as a single, large genus. 相似文献
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Hans V. Hansen 《Nordic Journal of Botany》1985,5(5):451-453
Gerbera L. sect. Pseudoseris (Baill.) Jeffr. (Compositae, Mutisieae) is endemic to Madagascar. It is not known in detail and cannot be revised, but it appears to include eight species, which are typified in this paper. The taxonomic state of the section is briefly discussed. 相似文献
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依据最新广义大丁草属的概念对中国产这一属群的植物进行了订正,亦即中国有大丁草属Leibnitzia Cass,火石花属Gerbera Cass.和兔耳一支箭属Piloselloides(Less.)C.Jeffrey ex Cufod。并对一些名称进行了认真的查考和相应的分类学处理,讨论了相应的地理替代与地质历史的关系。经整理,中国大丁草属含4种,火石花属可能含6种,兔耳一支箭属含1种。以横断山为核心的中国西南部也许是该属群的一个多样化中心和分化中心。 相似文献
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INÊS CORDEIRO DANIELA SANTOS CARNEIRO-TORRES 《Botanical journal of the Linnean Society. Linnean Society of London》2004,146(2):247-250
During a study of the genus Phyllanthus (Phyllanthaceae) in Chapada Diamantina, Bahia, a new species Phyllanthus gongyloides Cordeiro & Carneiro-Torres sp. nov. was found and is described and illustrated here. It is probably endemic to the area and is placed in subgen. Phyllanthus , sect. Phyllanthus , subsect. Clausseniani G. L. Webster. A new couplet to Webster's available key to the subsection is provided . © 2004 The Linnean Society of London, Botanical Journal of the Linnean Society , 2004, 146 , 247–250. 相似文献
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A new species of Baccharis L. sect. Caulopterae DC. (Compositae) of the high altitude grasslands of Southern Brazil is presented: Baccharis sphagnophila A. A. Schneid. & G. Heiden. The new species is described, illustrated and compared with similar species. 相似文献
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本文报道了寄生于菊科植物大丁草(Leibnitzia anandria)上的盘梗霉的一个新种——大丁草盘梗霉(Bremia leibnitziae sp. nov.)。它的形态特征与小孢盘梗霉(B. microspora)较为接近,但根据新种的孢囊梗分枝次数较多,且有时不规则,孢子囊体积较小,卵孢子容易形成以及寄主的差别等特点,可以将它们区别开。 相似文献
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P. B. HEENAN M. I. DAWSON S. J. WAGSTAFF 《Botanical journal of the Linnean Society. Linnean Society of London》2004,146(4):439-446
Sophora tomentosa , the type species of the genus Sophora , is shown by phylogenetic analyses of rbc L and ITS sequence data to be sister to Sophora sect. Edwardsia . S. tomentosa and most of the species from sect. Edwardsia share hypogeal germination, exstipulate leaves, and terete filaments. These species have buoyant seeds, and are distributed by ocean currents throughout the pantropics ( S. tomentosa ) and around southern temperate oceanic islands (sect. Edwardsia ). S. tomentosa differs from the species of sect. Edwardsia by its frutescent growth habit, terminal elongate inflorescence and smooth-walled legume. S. macrocarpa is unusual in sect. Edwardsia as its leaves have stipules, the filaments are winged, and the legume is smooth-walled. © 2004 The Linnean Society of London, Botanical Journal of the Linnean Society , 2004, 146 , 439–446. 相似文献
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The genus Swertia is one of the large genera in Gentianaceae, including 154
species, 16 series and 11 sections. It is disjunctly distributed in Europe, Asia, Africa and N.
America, but entirely absent from Oceania and S. America.
According to Takhtajan’s (1978) regionalization of the world flora, Swertia is found in
14 regions. Eastern Asiatic region with 86 species, of which 58 are local endemics, 13 series
and 9 sections, ranks the first among all the regions. The highest concentration of the taxa
and endemics in Eastern Asiatic region occurs in SW China-Himalayan area (Sikang-Yunnan
P. , W. Sichuan, W. Yunnan-Guichou Plateau of China and NE. Burma, N. Burmense P. ,
E. Himalayan P. and Khasi-Manipur P. ). In this area there are 74 species (48 endemics),
12 series, and 9 sections; thus about half species of the world total, three quarters of series
and 82% of sections occur in this small area. Besides, the taxa at different evolutionary
stages in Swertia also survive here. It is an indication that SW. China-Himalayan area is a
major distribution centre of the genus Swertia. In addition, Sudan-Zambezian Region in
Africa, with 22 species, 4 series and 2 sections, is a second distribution centre.
The primitive type of the genus Swertia is Sect. Rugosa which consists of 2 series and
23 species. It is highly centred in the mountains of SW. China (Yunnan, Sichuan, Guizhou
and SE. Xizang) where 2 series and 16 species occur. Among them 15 species of Ser. Rugosae were considered as the most primitive groups in this genus. From our study, the outgroup of Swertia is the genus Latouchea Frahch. , which is distributed in Yunnan, Sichuan,
Guizhou, Hunan, Guangdong, Guangxi and Fujian. The two groups overlap in distribution
in SW. China. According to the principle of common origin, the ancestor of two genera ap peared most probably in this overlapping area. It was inferred that SW. China Was the birth-place of the genus Swertia.
Four sections of Swertia have different disjunct distribution patterns: Sect. Ophelia is of
Tropic Asia, Africa and Madagascar disjunct distribution; sect. Swertia is of north temperate distribution; sect. Spinosisemina is in Tropical Asia (Trop. India to S. China and Philipines); sect. Platynema also is in Tropical Asia (Java, Sumatra, Himalayas to SW. China).
These disjunct patterns indicate that the Swertia floras between the continents or between
continent and islands have a connection with each other. From paleogeographical analysis,
Swertia plants dispersed to Madagascar before the Late Cretaceous, to SE. Asian Islands in
the Pleistocene, to North America in the Miocene. The distribution of Swertia in Madagascar might be later than that in Asia. Therefore the origin time of the genus Swertia was at
least not later than the Late Cretaceous, and might be back to the Mid-Cretaceous.
The genus Swertia first fully developed and differentiated, forming some taxa at different evolutionary stages (Rugosa, Swertia, Poephila, Ophelia and Platynema etc. ) in the original area, and these taxa quickly dispersed in certain directions during the Late Cretaceous-Middle Tertiary when the global climate was warm and no much change. There seem
to be three main dispersal routes from the origin area to different continents; (1) The westward route i. e. from SW. China, along the Himalayas area to Kashmir, Pakistan,
Afghanistan and Iran, and then southwestwards into Africa throuth Arabia. Four sections
(Poephila, Macranthos, Kingdon-Wardia and Ophelia) took this dispersal route. Most
species of sect. Ophelia dispersed along this route, but a few along southern route and north
ern route. Sect. Ophelia greatly differentiated in Africa and the African endemic sectionSect. Montana was derived from it. The two sections form there a second distribution center
of Swertia. (2) The southward route, i. e. towards S. India through the Himalayas, and
towards SE. Asian islands through C. and S. China, Indo-China. Along this dispersal route
sect. Platynema, Sect. Spinosisemina and a few species of Sect. Ophelia dispersed; (3) The
northward rout, i. e. northwards across N. China, C. Asia to a high latitude of Euasia,
and also through E. Asia into N. America. The following groups took this route: sect. Rugosa, sect. Swertia, sect. Frasera, sect. Heteranthos and sect. Ophelia ser. Dichotomae.
Therefore, it seems that the genus Swertia originated in SW. China and then dispersed
from there to N. and S. Asia, Africa, Europe and North America and formed the moderndistribution pattern of this genus. 相似文献
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Gloria E. Barboza 《Nordic Journal of Botany》2003,23(2):155-168
The delimitation of Solanum sect. Chamaesarachidium, as well as its relationship with sect. Episarcophyllum and certain species of sect. Solanum, is presented. Three species are included in Solanum sect. Chamaesarachidium (S.annuum, S.chamaesarachidium, and S.gilioides), which are described in detail and illustrated. The following combination of characters defines Solanum sect. Chamaesarachidium: the small annual habit, the pinnatifid to pinnatisect leaf blade, the inflorescence opposite or subopposite to the leaves, the number of flowers per inflorescence (3–14), the campanulate corolla, the very small anther size (1.1–2.7 mm long), the accrescent fruiting calyx with a well-marked venation, the absence of sclerosomes in the pericarp, the tuberculate seed coat, and the Andean habitat. 相似文献
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Ortíz, S. & Oubiña, J.R. 1995. Dicoma hindana (Asteraceae), a new species from Somalia. - Nord. J. Bot. 15: 187–189. Copenhagen. ISSN 0107–055X.
A new species of the genus Dicoma (sect. Psilocoma ), from Somalia, is described. The characteristics by which it can be distinguished from related species are listed. 相似文献
A new species of the genus Dicoma (sect. Psilocoma ), from Somalia, is described. The characteristics by which it can be distinguished from related species are listed. 相似文献
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Our study represents the first phylogenetic analyses of the genus Gagea Salisb. (Liliaceae), including 58 species of Gagea and 6 species of the closely related genus Lloydia Salisb. ex Rchb. Our molecular results support the infrageneric classification of the genus Gagea in sections according to Levichev and demonstrate that Pascher's subdivision of this genus into two subgenera can no longer be upheld. Certain Gagea sections (e.g., Gagea, Minimae, and Plecostigma) are well supported by cpDNA and nrDNA data. Gagea sect. Fistulosae is closely related to G. sect. Didymobolbos. Gagea sect. Graminifoliae and G. sect. Incrustatae are closely related to G. sect Platyspermum. The analyses support the monophyly of Gagea and Lloydia collectively. The molecular analyses reveal the basal position of G. graeca in proportion to all other species of Gagea and Lloydia investigated. Minor morphological differences could be established between both genera which support their close relationship. 相似文献
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The present article is the first comprehensive treatment of phytogeography of Thermopsis
(Fabaceae) in the world. Thermopsis is one of the few genera within Fabaceae with the distribution
pattern of the East Asia-North American disjunction. The distribution patterns of 5 recognized sections (including a new one) covering 21 species in Thermopsis are analyzed, and the results show
four centres of frequency of the genus: the Eastern Asiatic Region (9 spp. / 3 sects., including 4
endemic species), the Irano-Turanian Region (7 spp./3 sects., including 3 endemic species), the
Rocky Mountain Region (7 spp./2 sects., all endemic), and the Atlantic North American Region
(3 spp. / 1 sect., all endemic). In the light of the fact that most species and sections, a number of
phylogenetic series of the genus, and the most primitive sections and most advanced sections in
Thermopsis occur in the East Asia, the Eastern Asiatic Region might be the centre of diversity of the
genus. As the Irano-Turanian Region and the Rocky Mountain Region were just second to that of
Eastern Asiatic Region in number of sections and species, and many polyploids appeared in these
regions, they were considered as the secondary centres of distribution and speciation of the genus.
The speciation looks to be frequent and complex in these regions, and many new taxa have been described from there while many new reduced or incorporated taxa have happened over there. However, recent molecular data has shown that two reduced taxa of Thermopsis are distinct in these regions. Based on the modern distribution patterns and evolutionary trends in morphological characters
of the genus, and available fossil record of the genus and the historical geology, we speculate that
Thermopsis had already existed on Eurasia and North America before the Late Miocene, and probably originated from an ancestral form of Sophora-like taxa with lupine alkaloids somewhere in the
Laurasia in the Early Tertiary or Late Cretaceous. After the separation of the two continents, species
on different continents developed distinctly under influences of different evolutionary factors. In
Asia, the late Tertiary orogeny, disappearing of the Tethys and aridity and freezing caused by the
Quaternary glaciation were the main forces to promote the speciation and evolutionary processes,
whereas in North America it was the Quaternary glaciation and the orogeny of partial area to promote
evolution of the genus. According to the evolutionary trends in Thermopsis and the distribution pattern of the primitive taxa, Sino-Japanese Subregion of Eastern Asiatic Region may be considered asthe centre of primitive forms of Thermopsis. 相似文献
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Hisayoshi Nozaki Niji Ohta Hiroyoshi Takano Makoto M. Watanabe 《Journal of phycology》1999,35(1):104-112
The chloroplast-encoded atp B gene was sequenced from 33 strains representing 28 species of the colonial Volvocales (the Volvocaceae and its relatives) to reexamine phylogenetic relationships as previously deduced by morphological data and rbc L gene sequence data.1128 base pairs in the coding regions of the atp B gene were analyzed by MP, NJ, and ML analyses. Although supported with relatively low bootstrap values (75% and 65% in the NJ and ML analyses, respectively), three anisogamous/oogamous volvocacean genera— Eudorina, Pleodorina, and Volvox, excluding the section Volvox (= Euvolvox, illegitimate name), constituted a large monophyletic group (Eudorina group). Outside the Eudorina group, a robust lineage composed of three species of Volvox sect. Volvox was resolved as in the rbc L gene trees, rejecting the hypothesis of the previous cladistic analysis based on morphological data that the genus Volvox is monophyletic. In addition, the NJ and ML trees suggested that Eudorina is a nonmonophyletic genus as inferred from the morphological data and rbc L gene sequences. Although phylogenetic status of the genus Gonium is ambiguous in the rbc L gene trees and the paraphyly of this genus is resolved in the cladistic analysis based on morphological data, the atp B gene sequence data suggest monophyly of Gonium with relatively low bootstrap values (56–61%) in the NJ and ML trees. On the basis of the combined sequence data (2256 base pairs) from atp B and rbc L genes, Gonium was resolved as a robust monophyletic genus in the NJ and ML trees (with 68–86% bootstrap values), and Eudorina elegans Ehrenberg represented a paraphyletic species positioned most basally within the Eudorina group. However, phylogenetic status and relationships of the families of the colonial Volvocales were still almost ambiguous even in the combined analysis. 相似文献