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1.
Rungia sinothailandica (Acanthaceae), a new species from Yunnan, China and Chiang Rai, Thailand is described and illustrated. A colour plate, line drawing and distribution map of R. sinothailandica are provided. Rungia sinothailandica is similar to R. pinpienensis H. S. Lo, but differs in the broadly ovate sterile bracts and obovate‐elliptic fertile bracts, the crispate and tawny bracts margin, the 2‐lobed upper lip of the corolla and puberulent capsule. It is also similar to R. burmanica (C. B. Clarke) B. Hansen, but is easily distinguished by pubescent stems and leaves, the cymbiform‐oblong bracteoles and the 2‐lobed upper lip of corolla.  相似文献   

2.
Impatiens liboensis K. M. Liu & R. P. Kuang, a new species collected from Xiaoqikong Scenic Area in southern Guizhou, China, is described and illustrated, including its seed and pollen micro‐morphology. Impatiens liboensis is similar to I. chishuiensis Y. X. Xiong and I. tubulosa Hemsl., but differs by having obviously irregular underground tubers, white or pink–white flowers, lower sepal with a 1.2–1.5 cm long spur, obovate dorsal petal, and obovate‐oblong or obliquely obovate lower lobes of the lateral petals with retuse apex.  相似文献   

3.
Flowers commonly face the dilemma of needing to be attractive to pollinators but unattractive to nectar robbers or florivores. When the pollinator has chewing mouthparts, there is also a considerable risk of the pollinator consuming the flowers. Scant field records indicate that the florivorous beetle Erioscelis emarginata (Mannerheim) (Coleoptera: Scarabaeidae: Cyclocephalini), which pollinates Philodendron spp., feeds selectively on the sterile staminate flowers. Here, the hypothesis was tested that E. emarginata prefers sterile staminate flowers of Philodendron bipinnatifidum Schott and Philodendron melinonii Brongn. ex Regel (Araceae) over fertile flowers. This study also examined whether such a preference exists regardless of the proportion of fertile vs. sterile flowers in each Philodendron species. Analysis of nutritional and defensive compounds plus scanning electron microscopy on each flower type were performed. The feeding preference of florivores for either P. bipinnatifidum or P. melinonii was also examined. In both species, sterile flowers were significantly more consumed than fertile ones. The sterile zone of P. bipinnatifidum was significantly larger than that of P. melinonii, and sterile staminate flowers of both plants were consumed at similar rates. Calcium oxalate was markedly low in sterile flowers, which also presented smaller papillae than the other flowers. This study presents evidence that the balance between pollination and florivory has most likely evolved through a strong feeding preference for less‐defended sterile flowers regardless of the size of the sterile zone.  相似文献   

4.
Lucia Roncaglia 《Grana》2013,52(2):81-88
Anther development, microsporogenesis, and microgametogenesis were studied using both light and TEM microscopy in the six accessible subdioecious/cryptically dioecious species of Consolea (Cactaceae). Anther wall development, microsporogenesis, and microgametogenesis are uniform in staminate flowers of all six species, and are typical for Cactaceae. Breakdown of microsporogenesis in male‐sterile anthers occurs early, at the onset of meiosis, and results in anthers bearing no pollen grains. The abortive process follows a common pattern in all investigated species. The tapetum is the first layer to deviate from normal male‐fertile anther development. Tapetal cells in male‐sterile anthers elongate at an early stage and have abundant rER with atypical configurations. Ultimately, the tapetum becomes hypertrophied and non‐functional. Male‐sterility in pistillate flowers appears to be directly related to these anomalies. In addition, other anther layers and tissues are affected, and normal patterns of programmed cell death (PCD) are disrupted. The relationship between these patterns and the pattern of PCD in normal male‐fertile anthers is discussed. We hypothesize a single origin for the cryptically dioecious/subdioecious breeding system of Consolea based on the uniformity of the anther's abortive processes in pistillate flowers.  相似文献   

5.
在研究新疆阿勒泰地区柳属(SalixL.)植物时发现了新疆杨柳科(Salicaceae)柳属植物新记录组粉枝柳组(Sect.Daphnella Seringe ex Duby)及新疆新记录种粉枝柳(Salix rorida Laksch.)。该种雌花苞片长圆形、倒卵状长圆形、倒卵状椭圆形和倒卵形,先端锐尖,苞片基部两侧各具3~4个腺点;雄花苞片倒卵形和倒卵状长圆形,先端锐尖,稀凹陷,在个别苞片基部一侧会有不明显的2~3个腺点,与其他分布区的粉枝柳稍有差异。主要分布在哈巴河中、上游及其2个支流,生于河岸及人工渠道岸边,海拔900~1 500m之处。  相似文献   

6.
Framed inflorescences are unique arrangements in which a cluster of small fertile flowers is surrounded by several larger, decorative sterile flowers. Viburnum (Adoxaceae) species vary in their inflorescence arrangements; some species exhibit framed inflorescences, whereas others do not. We hypothesize that the decorative flowers increase the pollinator-attracting functions of the inflorescences; as proved by previous studies, they additionally function as landing-sites for pollinators. To test our hypotheses, field manipulation experiments were carried out for nine Viburnum species, three with inherently framed inflorescences and six without them: sterile flowers were removed and mounted on species with and without framed inflorescences, respectively. Results show that inflorescences with decorative flowers had higher visit rates than inflorescences without them, and that insect flower visitors did not show landing preference for either flower type. These results suggest that decorative flowers appeared only in a subset of Viburnum species to increase their pollination chances by, mainly, enhancing the attractiveness of the inflorescence. It is likely that species without framed inflorescences use other attraction-enhancing mechanisms, such as a high flowering synchrony within a single cluster of fertile flowers, a trait found in most studied species without decorative flowers.  相似文献   

7.
A new species of Clausena, C. agasthyamalayana is described and illustrated from the southern Western Ghats, Kerala, India. It is similar to C. indica but differs from it being of dwarf habit, and having greenish–black bark, smaller and fewer leaflets, obovate and coriaceous leaves with obtuse or emarginated apex, elliptic and obtuse petals, oblong‐cordate anthers, consistently 4‐locular ovary with 2 ovules in each chamber and ellipsoid fruits.  相似文献   

8.
该文报道了采自中国浙江庆元县百山祖国家级自然保护区木兰科含笑属一新种——尾叶含笑(Michelia caudata M.X.Wu,X.H.Wu & G.Y.Li),该种与野含笑(M.skinneriana)和紫花含笑(M.crassipes)相近,但与野含笑的区别在于叶片倒卵形至倒卵状椭圆形,叶背面密被黄褐色茸毛,长5~7.5 cm,宽2.5~3.2 cm,先端尾尖,侧脉每边约6对,花被片椭圆形;与紫花含笑的区别在于花被片淡黄色,雌蕊群柄长3~4 mm。根据国际自然及自然资源保护联盟(IUCN)红色名录分类标准,尾叶含笑濒危等级为极度濒危。  相似文献   

9.
Job Kuijt 《Brittonia》1990,42(1):66-69
The combinationLigaria teretiflora (Rizzini) Kuijt is proposed, based onPsittacanthus teretiflorus Rizzini, adding a second species to the genus.Ligaria teretiflora differs fromL. cuneifolia (Ruiz & Pavón) Van Tieghem in having articulated pedicels and obovate leaves which lack a necrotic apex.  相似文献   

10.
A new species of the family Magnoliaceae, Manglietia sapaensis N. H. Xia & Q. N. Vu from Lao Cai Province, northern Vietnam, is described and illustrated. The well marked species appears to be most closely related to M. garrettii Craib, but differs in being a smaller tree, with shorter petioles not pulvinate at base, leaf‐lamina oblong to oblong‐elliptic, white flowers, and pubescent gynoecium.  相似文献   

11.
A new species of the genus Ranunculus, R. uttaranchalensis, is described from Gangotri National Park, Uttaranchal in Western Himalaya, India. It is distinguished from the closely allied R. lobatus in having radical leaves sub‐cordate with hairy lamina base and petiole hairy above; cauline leaves sessile, 3–7 lobed with linear to narrowly lanceolate lobes; sepals usually reddish brown, externally hairy; petals rounded‐obovate and oblong, receptacle glabrous except 1–3 hairs at the top.  相似文献   

12.
Lygodium microphyllum (Cavanilles) R Brown (Lygodiaceae), Old World climbing fern, invades wildlands in central and southern Florida, USA, and causes considerable habitat disturbance. Efforts to develop an effective biological control strategy have focused on several folivorous insects and a leaf‐galling mite from southeast Asia and Australia. Neomusotima conspurcatalis Warren (Lepidoptera: Crambidae) is a foliage‐feeding moth that specializes on Lygodium species. First released in 2008, N. conspurcatalis successfully established in Florida and is dispersing throughout the L. microphyllum‐invaded range. We investigated whether N. conspurcatalis display any preference (oviposition or larval feeding) between two leaflet morphologies, i.e., fertile spore‐producing vs. sterile leaflets. Furthermore, we examined whether oviposition and no‐choice diets on either fern leaflet type conferred any possible selective advantages (e.g., weight, emergence success) to the offspring. Finally, we analyzed leaf nitrogen and carbon content and leaf volatiles to gauge differences between the leaflet types. In choice and no‐choice scenarios, larvae consume approximately the same amount of leaf area and display no preference between fertile and sterile leaflets. However, females deposited significantly more eggs on fertile than on sterile leaflets. Oviposition choice had no effect on larval development times, pupal weights, or successful eclosure. Nitrogen and carbon content did not differ between fertile and sterile samples, but sterile leaflets contain more 1‐octen‐3‐ol, which may act as an herbivory deterrent. The propagule attack imposed by N. conspurcatalis feeding on fertile leaflets is unlikely to provide adequate control, but could be beneficial as part of a suite of biological control agents and other control methods.  相似文献   

13.
14.
Two new species of the orchid genus Quekettia are described. Colombian Quekettia aureliae is distinguished from similar Q. microscopica by the pandurate lip with a pair of small, flap‐like calli in the isthmus between hypo‐ and epichile, and deeply emarginated epichile apex. Quekettia senghasiana found in Guyana resembles Q. papillosa but it is characterized by the free lateral sepals, oblanceolate, obtuse petals and much larger lip which is oblong–obovate in outline and with lip disc being papillate only near the base.  相似文献   

15.
In this study, the cypsela morphology of 21 (14 species) of the 28 (17 species) Turkish Cirsium Mill. sect. Cirsium (Asteraceae) taxa was examined by stereomicroscope and scanning electron microscope (SEM). The shapes of cypselas are oblong, obovate, narrowly obovate and oblanceolate. The taxa were divided into 7 main types according to the results of SEM investigation on cypsela surface characteristics as: scalariform, ribbed, scrobiculate-ribbed, scrobiculate, scrobiculate-reticulate, reticulate and bireticulate. Taxonomic significance of cypsela morphology is discussed. It is shown that cypsela features can be used as distinguishing characteristics in some Cirsium sect. Cirsium species.  相似文献   

16.
Gardenia jasminoides J. Ellis, a plant native to southern China, was introduced into Britain in the mid‐18th century in its sterile double‐flowered form. It quickly became a horticultural sensation because of its large white jasmine‐like flowers and scent. At first, understanding the taxonomic placement of the species was inhibited by the lack of fertile flowers, but eventually the species was understood to be very different from a true jasmine. Interest in this plant in the mid‐18th century was not confined to its use as an ornamental, but also focused on the potential use of its seeds as the source of a yellow‐scarlet dye.  相似文献   

17.
Flexible pedicels are characteristic of birdpollinated plants, yet have received little attention in studies of hummingbird-flower interactions. A major implication of flexible pedicels is that flowers may move during pollination. We examined whether such motion affected interactions between ruby-throated hummingbirds (Archilochus colubris) and jewelweed (Impatiens capensis) by increasing pollen deposition and by altering the effectiveness of nectar removal. For I. capensis, flower mobility enhanced pollen deposition: birds had significantly longer contact with anthers and more pollen deposited on their bills and crowns when foraging at mobile flowers than at flowers that had been experimentally immobilized. In contrast, flower mobility imposed a cost on hummingbirds by significantly increasing their handling times and reducing their extraction rates relative to their interactions with immobile flowers. Field observations indicated that the motion observed during hummingbird visits did not occur when bees (Bombus spp., Apis mellifera) visited I. capensis flowers, which suggests that the mobility of I. capensis flowers is an adaptation for hummingbird pollination.  相似文献   

18.
Tilia chinensis Maxim. is widespread and locally frequent in the mountains of south‐western China, mainly in Yunnan and Sichuan. It occurs in mixed evergreen‐deciduous, broad‐leaved forests and extends up to over 3000 m in coniferous forests and birch woodland. The species is very distinct and easily recognised by its normally orbicular, serrate leaves, sessile or shortly stalked, oblong bracts, cyme with only three flowers and large ellipsoidal fruits with longitudinal ribs, especially prominent when dry. Evidence is summarised for including T. intonsa Wilson, T. laetivirens Rehd. & Wilson and T. yunnanensis Hu within T. chinensis. Until recently T. chinensis was rare in cultivation in the British Isles and confined to botanic gardens and arboreta. Young trees grow slowly but leaf‐out late and usually avoid damage from spring frosts; they grow well on moist but freely draining, moderately fertile soils in the shelter of glades.  相似文献   

19.
Gynodioecy, the phenomenon of having both hermaphrodite and female (i.e. male‐sterile) individuals within the same population, is an important intermediate step in the evolution of separate sexes in flowering plants. In this study, we investigated the floral micromorphology and microsporogenesis of the gynodioecious herb Glechoma longituba from four natural populations in Korea. The floral micromorphological characters of the different sex morphs were examined and compared using scanning electron microscopy (SEM), and the ultrastructure of microspores during microsporogenesis was studied. We also examined the development of anthers and pollen grains in the three sexual morphs (i.e. hermaphrodites, females, and gynomonoecious, i.e. individuals with a mixture of female and hermaphroditic flowers) by embryological investigation. The major difference in anther development between the three phenotypes was the early disintegration of the tapetal cells in the anthers of female flowers. While mature fertile pollen grains were found in both hermaphrodite and gynomonoecious phenotypes, females did not produce any pollen grains. In addition, both fertile and sterile pollen grains in gynomonoecious phenotypes were frequently observed. The results of the present study indicate that floral micromorphological characters were not distinct between sexual morphs of G. longituba, except for the structure of the inner cell surfaces of the anther. The observed tapetum abnormalities and degeneration of pollen grains in both gynomonoecious phenotypes and females may be the consequence of inbreeding depression in hermaphrodites.  相似文献   

20.
Valeriana scandens presents perfect and pistillate flowers, the latter with sterile anthers. The species is composed of two varieties with different ploidy; V. scandens var. scandens (2n = 28) and V. scandens var. candolleana (2n = 56), both of which occur in RS, Brazil. Crosses between these varieties may give rise to hybrids with pollen sterility. In this study, we analyzed the microsporogenesis and microgametogenesis of sterile and fertile anthers, and also investigate whether pollen sterility is caused by an irregular meiotic process. Developmental analysis using light microscopy and scanning electron microscopy showed that sterile anthers develop similarly to fertile anthers until the end of meiosis. After this stage, sterile tetrads do not separate as a consequence of exine fusion between adjacent microspores, which is similar to sterile pollen of Brassica ms-cdl1 mutants. In addition, vacuolated immature pollen grains degenerate after separation. The cytogenetic analysis of the microspore mother cell (MMC) showed that the diploid population of V. scandens var. scandens (2n = 28) has pollen sterility that is not caused by a cytogenetic disturbance. The MMCs analyzed from prophase I to tetrad stage showed a regular meiotic process, indicating the phenotype of V. scandens sterile pollen is a postmeiotic process formed by fusion of exine between opposite microspores.  相似文献   

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