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1.
A new species,Oreocharis xieyongii T.Deng,D.G.Zhang & H.Sun,from Hunan Province,central China,is described.The combination of purple zygomorphic corolla with longer adaxial lobes and exserted stamens defines the species and discriminates it from all other current Oreocharis species.Morphological traits of the new species were compared to those of two similar species,Oreocharis xiangguiensis and 0.rubrostriata.Phylogenetic analysis indicates that the new species is nested within the Oreochari...  相似文献   

2.
The neotropical plant genus Drymonia displays a remarkable variety of floral shapes and colors. One feature that is particularly important to coevolution with pollinators involves the variable shapes and widths of corolla tubes. To evaluate the evolutionary context for changes in corolla shape, we constructed a phylogeny of 50 of the 75 species of Drymonia using molecular markers from plastid (trnK-matK) and nuclear regions (ITS and ETS). Mapping tube shapes on the phylogeny supports open, bell-shaped (campanulate) corolla shape as the ancestral character state for Drymonia, with multiple independent origins of constriction in the corolla tube. Corollas with constrictions take one of three tube shapes: a constricted flower opening and throat with a large, expanded pouch on the lower surface (hypocyrtoid); a constricted flower opening and throat lacking an expanded pouch on the lower surface (urceolate); or a constricted opening and throat where the sides of the corolla appear laterally compressed. Fieldwork demonstrates euglossine bees (mostly Euglossa spp. and Epicharis spp.) visit campanulate corollas while hummingbirds visit corollas that are constricted. Results support eight independent origins of constricted corolla tubes from ancestors with campanulate corolla tubes: 3 hypocyrtoid clades, 3 laterally compressed clades, and 3 urceolate clades (one of which represents a shift from a hypocyrtoid ancestor). Constricted corollas are associated with shifts from the ancestral condition of poricidal anther dehiscence, which presents pollen to pollinators in multiple small doses, to the derived condition of longitudinal anther dehiscence, which presents all pollen to pollinators simultaneously. The association of hummingbird pollination with constricted corolla tubes suggests that narrowing evolved as a barrier mechanism that prohibits the visitation of flowers by bees.  相似文献   

3.
John L. Clark 《Brittonia》2013,65(2):181-185
A new species, Drymonia ignea (Gesneriaceae, tribe Episcieae), is described from the eastern slopes of the Ecuadorian Andes from the provinces of Tungurahua, Napo, and Morona-Santiago. It differs from other species of Drymonia by the presence of an urceolate corolla, quadrangular stem, and cucullate calyx lobes.  相似文献   

4.
Thomas F. Daniel 《Brittonia》1995,47(4):408-413
Justicia masiaca, a new species endemic to northwestern Mexico, is described, illustrated, and compared with the morphologically similarJ. longii. In its 4-aperturate pollen,Justicia masiaca is unique among those species ofJusticia with elongate, cylindrical corolla tubes that were previously treated inSiphonoglossa.  相似文献   

5.
Attraction of pollinators and successful pollen transfer represent the primary targets of selection during flower evolution, leading to repeated evolutionary shifts between pollinators and consequently to the diversification of floral forms. However, most studies in floral evolution focus on the characteristics of flowers with straight corolla tube. Here, we report on an unusual form of sigmoid corolla combined with protandry and herkogamy in a Chinese species of Gesneriaceae, Oreocharis pumila (formerly Opithandra pumila). Contrary to species with sigmoid corollas studied previously, the base of the corolla tube of this species is inclined at an oblique angle downwards before the tube bends forward, and the stigma and anthers are included in the upper part of the corolla tube. The plants were found to be self‐compatible but incapable of autonomous selfing. Successful pollination was found to depend fully on the presence of insect pollinators (Nomia sp.) and pollen grains are the greatest reward for the visitors. Different from the other sigmoid flowers, the sigmoid corolla of O. pumila was not found to favor insect pollinators with long flexible proboscises. A mechanical fit between floral morphology and pollinator was found, in which only small insect visitors with specialized visiting behavior are legitimate pollinators. The protandry combined with herkogamy in the sigmoid corolla tube strongly ensures pollination efficiencies. Oreocharis pumila is the only species with sigmoid corolla in the genus Oreocharis. We hypothesize that such a corolla has arisen through selection due to inadequate pollination in early spring in the mountainous habitat that O. pumila occupies.  相似文献   

6.
Two new rosulate species of Streptocarpus are described from the eastern seaboard of South Africa. The first is endemic to Mpumalanga Province. This species has almost actinomorphic corollas with small cylindrical tubes and was previously included within Streptocarpus parviflorus. However, molecular and morphological data and habitat preference do not support this classification. The second species is from the Msikaba River Gorge in the Eastern Cape Province. It adds to the already impressive list of endemic plant species from this region and is allied to other rosulate species of the Eastern Cape. It approaches Streptocarpus rexii in flower size but differs in its much shorter corolla tubes, which lack purple nectar guides. In addition, the corolla floors are marked with yellow bars reminiscent of Streptocarpus cyaneus and also seen in sympatric populations of the small‐flowered Streptocarpus modestus. © 2008 The Linnean Society of London, Botanical Journal of the Linnean Society, 2008, 158 , 743–748.  相似文献   

7.
8.
A new species of Primulina, P. moi, from Guangdong, China, is described and illustrated. It is similar to P. lijiangensis in leaf shape, but can be distinguished by several characters, such as base of corolla tube constricted, lobes of adaxial lip ovate, abaxial lip 3‐lobed from base, lobes elliptic or oblong elliptic with cuspidate apex, yellow corolla and filaments, two non‐adhesive anthers when corolla is open, adnate only before anthesis and 2 stamnoides.  相似文献   

9.
Primulina suichuanensis X. L. Yu & J. J. Zhou, a new species of Gesneriaceae from Jiangxi, China, is described and illustrated. Morphologically, the new species is most similar to P. roseoalba, but differs by entire leaf blade margin, narrowly ovate bracts, reddish–purple or bluish–purple corolla, 3.0–3.4 cm long corolla tube, white filaments, and 3.6 cm long pistil. It flowers from September to November.  相似文献   

10.
Boeica konchurangensis B.H.Quang, D.V.Hai & Mich.Möller, a new species of Gesneriaceae from the Gia Lai Province of Vietnam is described, illustrated, and colour photographs of the species are provided. This new species has an almost actinomorphic corolla and shows morphological similarities with B. porosa, but differs from it by a shorter peduncle, a near‐actinomorphic purple corolla with a distinctly broad campanulate tube and a shorter capsule.  相似文献   

11.
Martin Freiberg 《Brittonia》2000,52(2):203-209
The gesneriad flora of the Reserva Río Guajalito, Province of Pichincha, and Bosque Protector Otonga, Province of Cotopaxi, Ecuador have been investigated. Three new species,Gasteranthus aurantiacus M. Freiberg,G. atrolimbus M. Freiberg, andG. acuticarinatus M. Freiberg, are described and illustrated in preparation for a contribution for the Gesneriaceae in the Flora of Ecuador. While bothG. acuticarinatus andG. atrolimbus are characterized by a dorsal keel on a tubular, pink to wine-red corolla, the infundibulate, bright orange-colored corolla ofG. aurantiacus has a rather wide opening and a large limb.  相似文献   

12.
Primulina minor from the Daoxian county, Hunan province in China is described. This new species is similar to Primulina jingxiensis (Yan Liu, W. B. Xu & H. S. Gao) W. B. Xu & K. F. Chung and P. longzhouensis (B. Pan & W. H. Wu) W. B. Xu & K. F. Chung, but differs by its number of leaves (4–6), broadly ovate, orbicular‐ovate or orbicular leaf blade, 2–4 cymes, short peduncle (1.8–2.0 cm long), white (or white with light purple tinge) corolla, small corolla (8–10 mm long), 3 staminoides of which the lateral ones are short (0.75–0.90 mm long) and adnate to 1.6–1.7 mm above the corolla base.  相似文献   

13.
广西苦苣苔科稀有珍贵植物——弥勒苣苔   总被引:1,自引:0,他引:1  
首次报道广西苦苣苔科植物一新记录属:弥勒苣苔属.该属接近金盏苣苔属,但不同在于弥勒苣苔属花冠上唇4浅裂,下唇不分裂,2对雄蕊分别着生于花冠中部及其上方,雌蕊具一个柱头.弥勒苣苔属为中国特有的单型属,仅弥勒苣苔一种,分布于云南东南部和广西西部.该种在广西首次记录,凭证标本存放于广西植物标本馆(IBK).  相似文献   

14.
Protogyny is supposed to represent the ancestral form of dichogamy in the angiosperms, but is rare in advanced groups such as the Asteridae, in which protandry prevails by far. Here we report on an unusual form of protogyny combined with herkogamy in a Chinese species of Gesneriaceae (Asteridae–Lamiales): Oreocharis acaulis (formerly Opithandra acaulis). This is characterized by a conspicuous protrusion of the style from the flower bud and the stigma becoming receptive before corolla opening (female-only stage; preanthetic protogyny) and both sexes staying functional during anthesis (hermaphroditic stage), with the stigma presented above the anther level (approach herkogamy). The plants studied were found to be self-compatible, but autonomous self-pollination and apomixis were not observed. Successful pollination was found to depend fully on the presence of insect pollinators (Bombus sp.). The visiting frequency was higher in the hermaphroditic stage (in which also more nectar was produced) than in the female-only stage. The out-crossed flower buds opened earlier and had a shorter flowering period than selfed flowers. Similarly, the outcross-pollen germinated earlier and the pollen tube growth was faster than in self-pollen. Anthers, pistil and corolla of O. acaulis obviously form an integrative functional unit in which the elongated style plays a key role both in pollen-dispensing and pollen-deposition. The combination of preanthetic protogyny with herkogamy has probably arisen through selection for promoting out-crossing and prolonging the exposition time of the receptive stigma in order to capture a higher amount of pollen grains. This may be understood as a strategy to cope with scarcity of pollinators in the plants’ habitat.  相似文献   

15.
A new species of Gesneriaceae, Primulina melanofilamenta Ying Liu & F. Wen from Guangxi, China, is illustrated and described. It is morphologically distinct from the most similar species P. eburnea and P. atroglandulosa by the color of the corolla, dark purplish black filaments, anthers backed with a beard of white hairs, the length of staminodes and the hairs of styles. The somatic chromosome number of P. melanofilamenta is also reported as 2n = 36.  相似文献   

16.
最近被重新界定的广义石山苣苔属(Petrocodon Hance)是苦苣苔科(Gesneriaceae)一个中等大小的属,我国目前已知的有34种1变种,主要分布于我国华南至西南石灰岩地区。该文报道了于云南东南部马关县发现的该属一新种——细管石山苣苔(Petrocodon tenuitubus W. H. Chen,F. WenY. M. Shui)。该新种在形态上与陆氏细筒苣苔(P. lui)、细筒苣苔(P. hispidus)和长檐苣苔(P. jasminiflorus)相似,但其线形或披针形的苞片和小苞片均为3枚,花冠筒细小且弯曲,盘形柱头1,很容易区别于陆氏细筒苣苔和细筒苣苔;而其叶片卵形至圆形,花冠裂片卵形而尖端钝以及退化雄蕊3,则显著区别于长檐苣苔。该新种的发现对推进我国石灰岩地区苦苣苔科植物资源的发掘具有一定意义。主模式标本存放于中国科学院昆明植物研究所标本馆(KUN),等模式标本存放于广西植物研究所标本馆(IBK)。  相似文献   

17.
Two new species of Gesneriaceae, Wentsaiboea tiandengensis Yan Liu & B. Pan and Wentsaiboea luochengensis Yan Liu & W. B. Xu from Karst caves in Guangxi, China are described and illustrated. Wentsaiboea tiandengensis resembles W. renifolia, but differs in the leaf blade being cordate or broadly ovate, the margin crenate or repand, with conspicuous pinnate veins 3–5 on each side, corolla throat constricted, corolla lobes ovate with apex acute, staminodes 3, and ovary broadly ovoid. Wentsaiboea luochengensis is similar to W. renifolia, but can be distinguished from the latter by the coriaceous leaf blade with 2–3 inconspicuous pinnate veins on each side, elliptic or broadly ovate to sub‐rotund in shape, with sub‐entire margin and attenuate to cuneate or sub‐rotund base, broadly ovate or sub‐rotund corolla lobes, rotund or obtuse apex, and 3 staminodes.  相似文献   

18.
台闽苣苔(苦苣苔科)花部器官的形态发生   总被引:1,自引:0,他引:1  
在扫描电镜下对台闽苣苔 (T .oldhamii (Hemsl.)Solereder)进行了花部器官形态发生的观察 ,为探索该类群的个体发育、类群间的系统发育关系和进化趋势提供依据。研究发现该属植物萼片、花冠和雄蕊发生式样均为五数花类型 ,它们各自来源于花原基上分化出来的萼片原基、花冠原基和雄蕊原基 ;花冠与雄蕊的两侧对称性与花冠上唇生长稍快和退化雄蕊原基发育迟滞相关 ;萼片原基的发生和发育的顺序是不一致的 :萼片原基发生的式样为近轴中原基—远轴 2原基— 2侧原基 ,发育式样则为近轴中萼片— 2侧萼片—远轴 2萼片 ,花蕾时为镊合状排列。花冠裂片原基的发生和发育式样是一致的 ,即远轴中裂原基 (下唇中裂片 )—远轴 2侧裂原基 (下唇 2侧裂片 )—近轴 2裂原基 (上唇 2裂片 )。花蕾期卷迭式为覆瓦状排列 ,从外向内 :下唇中裂片—下唇 2侧裂片—上唇 2裂片或下唇 2侧裂片—上唇 2裂片—下唇中裂片。雄蕊原基与花冠裂片原基互生 ,前方雄蕊原基在发生上稍迟于后方雄蕊原基 ,后者与退化雄蕊原基几乎同时发生 ,但较小 ,并与近轴心皮 (或柱头上唇 )对生。将该属与玄参科 (Scrophulari aceae)的地黄属 (Rehmannia)、苦苣苔科 (Gesneriaceae)的异叶苣苔属 (Whytockia)和尖舌苣苔属 (Rhynchoglossum)的花部器官比较发现  相似文献   

19.
20.
Didymocarpus tonghaiensis J. M. Li & F. S. Wang sp. nov. from Yunnan, China, is illustrated and described. It is morphologically similar to D. stenanthos C. B. Clarke, but differs by having a densely glandular peduncle, 5‐lobed calyx with lobes that are free to the base, larger corolla, anther with white woolly hairs and a densely glandular‐hairy capsule.  相似文献   

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