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1.
The new species Dionysia assadii (Primulaceae) from the Irano–Turanian region in Fars province, Iran, is described and illustrated. It is compared with its closest relative Dionysia esfandiarii Wendelbo and differs from it in leaf shape, leaf margin, hair density of leaves and other organs, shape of calyx and bracts, color of corolla and status of lobes, form and color of seeds, as well as the length of anthers and style in longistylous flowers.  相似文献   

2.
A new species of Gesneriaceae, Primulina jianghuaensis K. M. Liu & X. Z. Cai, from a limestone cave in Hunan Province, China, is identified and described. Its seed and pollen grain morphology are described. The new species is morphologically closely related to P. lingchuanensis ( =Chiritopsis lingchuanensis) and P. danxiaensis ( =Chiritopsis danxiaensis), but it can be distinguished by its 12–25 (–30) leaves, ovate or broad ovate leaf blade, subcordate, truncate or slightly decurrent leaf base, undulate leaf margin, 5–20 cymes, and 2–3 staminodes.  相似文献   

3.
A new species of Cercestis (Araceae), C. hepperi Jongkind from Liberia is described and illustrated. It is characterised by comparatively long pedunculate inflorescences, very dark green leaf blade with a conspicuous yellow margin and short basal lobes and by abundant stolons with persistent scaly leaves (cataphylls). Cercestis sagittatus Engler, another species from Liberia, that was synonymised with C. dinklagei Engler by Ntépé‐Nyamè, is resurrected. A key to the species of Cercestis known from Liberia is provided.  相似文献   

4.
《Journal of bryology》2013,35(2):227-231
Abstract

Two new species of Cololejeunea (sub-genus Lep tocolea), C. pandei sp. nov. and C. dentifolia sp. nov. are described from fudia. Both species are epiphyllous with ascending leaves. The former is characterized by uniseriate stylus, serrated margin of leaf, discoid gemmae on ventral surface of leaf-lobe with 2-3 mamillose cells and inflated perianthwith lateral winged plicae. The latter is characterized by dentate margin of leaf, leaf-cells with distinct trigones and intermediate nodular, thickenings, bidentate leaf-lobule and discoid gemmae with 4 mamillose cells.  相似文献   

5.
Ilex sanqingshanensis, a new species of Aquifoliaceae from Jiangxi, China, is described and illustrated with morphological characteristics and ultrastructure of pollen grains. The new species is easily distinguished from the most similar species I. wugongshanensis C. J. Tseng ex S. K. Chen et Y. X. Feng by having smaller leaves that are elliptic, ovate or elliptic‐ovate, with shorter (0.5–1.0 vs 2–3 mm) teeth on the leaf margin, longer pedicels of staminate flowers (2.0–3.5 vs 1.5 mm), smaller pyrenes (3.5–4.0 × 2.0–2.5 vs 4.5–5.0 × 3.0 mm), and woody pyrenes (vs stony pyrenes).  相似文献   

6.
Chamaesium jiulongense X. L. Guo & X. J. He, a new species of Apiaceae from Mt Haite in Jiulong County, Sichuan Province, China, is described. The new species differs from other Chamaesium species by its ultimate segments of the leaves which are 1–3‐lobed, rarely entire, with a narrow, minutely incised, pale brown margin, as well as by the presence of leaf‐like bracts, bracteoles longer than flowers, pubescent styles and oblong fruit with obsolete calyx. Morphological and micromorphological characters of the new species are provided and illustrated.  相似文献   

7.
The adult leaf of Carludovica palmata consists of a plicate lamina, adaxial hastula, petiole, and sheath. The leaf is unusual in the angiosperms because about two-thirds of the apical meristem is utilized in its initiation. The adult leaf requires about 4–5 plastochrons to mature. Shortly after its initiation the adult leaf and apical meristem collectively appear pyramid-shaped and various parts of the mature adult leaf may be traced back to particular portions of the pyramid. Plications develop by differential growth within the lamina, not by splitting of leaf tissue. Quantitative studies indicate that certain regions of the developing adult leaf elongate more rapidly or slowly than other regions depending upon the stage of leaf development. The adult leaf of C. palmata develops differently from those of previously studied palms in various ways. It therefore appears less justifiable to consider the superficial similarity between the adult leaves of various Cyclanthaceae (particularly those of Carludovica sensu strictu) and those of fan palms as evidence of especial affinity between the Cyclanthaceae and Palmae. Juvenile leaves of C. palmata differ from adult leaves both in their mode of origin and appearance at maturity. The juvenile leaf appears homologous to the entire adult leaf.  相似文献   

8.
The leaf of mid Devonian Archaeosigillaria vanuxemii from Gilboa, N.Y. is known to have a thick conical base. This study demonstrates by the uncovering technique the attachment of leaves to the stem, the flattened lamina that is deltoid in outline with a toothed margin, and an apex prolonged into a hair. Comparisons are made with specimens from Kazakhstan. The morphology of leaves of other species of Archaeosigillaria and the slowly accumulating data on leaves of Devonian lycopods are discussed.  相似文献   

9.
10.
Didymodon mesopapillosus J. Kou, X.‐M. Shao & C. Feng is described and illustrated as a new species from Tibet, China. It is characterized mainly by its ovate to ovate‐lanceolate leaves appressed to weakly erect when dry, margins recurved from leaf base to apex, laminal cell superficial walls markedly thicker than the internal walls, laminal papillae present only on both sides of costa, short‐excurrent costa, undifferentiated basal cells and differentiated perichaetial leaves. This species is compared with similar species and its ecology is discussed.  相似文献   

11.
Leaves in most extant Ephedra ‐species represent only rudimentary scales without chlorophyll. Photosynthesis is completely restricted to green shoots. Only some species, e.g. Ephedra altissima, develop folious leaves even when being mature. Morphology and anatomy of cotyledons, primary leaves, and subsequent folious leaves of Ephedra altissima were examined particularly with special focus on their vasculature. The results show that the reduction of the leaves is achieved by an extreme reduction of the adaxial leaf surface. Most parts of the leaf surface are therefore developed by the abaxial side. Apart from a reduced lamina, a thick cuticle and sunken stomata are the only xerothermic adaptations in leaves of Ephedra altissima. A hypodermis and endodermis are also not developed. The anatomical results indicate that ancestors of modern Ephedra‐ species might have evolved in a more humid climate, contrasting to the arid habitats in which extant Ephedra‐ species are native today. (© 2013 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)  相似文献   

12.
Two new species of Centaurea L. sect. Cynaroides Boiss. ex Walp. (Asteraceae), C. shahuensis Ranjbar and Negaresh and C. ravansarensis Ranjbar and Negaresh are described and illustrated from Kermanshah Province, west Iran. They are closely related to C. regia Boiss. subsp. regia. However, C. shahuensis differs from it by median stem leaves broadly oblanceolate or subpandurate, phyllaries densely lanate‐tomentose, appendages small, concealing a minor part of phyllaries, and also median appendage margin entire sometimes with 1–2 cilia, 1.2–3.0 mm long on each side. Centaurea ravansarensis is distinguished by upper stem leaves loosely arachnoid, phyllaries loosely floccose‐tomentose, inner appendages deep brown to blackish, and spine 4.5–6.0 mm long. Habitat, conservation status and the geographical distribution of the new species are given.  相似文献   

13.
Erysimum damirliense, a new species of Brassicaceae from Zanjan and Ardebil provinces (northwest Iran) is described and illustrated. The new species resembles E. uncinatifolium and E. elbrusense, but is easily recognized by its life form, basal leaf margin, indumentum of cauline leaves, number of flowers in the main raceme, fruit width and style length. Phylogenetic analysis of internal transcribed spacer (ITS) DNA sequences confirm that the new species is distinct from morphologically similar species.  相似文献   

14.
为探讨生境对卷柏属(Selaginella)植物微观形态的影响,利用扫描电子显微镜对海南七仙岭采集的7种卷柏属植物的侧叶、中叶、孢子叶的叶表皮形态以及小孢子形态进行全面观察分析,并计算气孔器大小、气孔密度、孢子大小等,比较分析其微观形态的区别及微形态与生境间的关系,为卷柏属植物的分类提供依据。结果显示:(1)同种卷柏属植物的侧叶、中叶与孢子叶在叶表皮形态上具明显差异,尤其是孢子叶上的气孔与营养叶相对较小且稀疏,与孢子叶的繁殖功能相符合。(2)不同种卷柏属植物的叶表皮特征也明显不同,主要表现在叶缘刺、气孔和瘤状突起上,表明这些特征可以作为卷柏属植物种间区分的依据。(3)卷柏属植物的小孢子形态稳定,纹饰多样;部分种间的小孢子形态相似,但可通过纹饰类型、裂缝的曲直进行区分。(4)琼海卷柏的小孢子具有独特的网状纹饰,暗示其具有独特的演化途径。(5)卷柏属植物叶表皮的气孔特征、瘤状突起特征,小孢子的颜色、纹饰,与海拔、生境的湿度有一定的相关性,但其形成机理有待进一步研究。  相似文献   

15.
Saussurea haizishanensis B. Q. Xiu, G. Hao & N. H. Xia sp. nov., a new species from Sichuan, China, belonging to Saussurea subg. Eriocoryne (DC.) Hook. f. sect. Cincta Lipsch., is described and illustrated. It is similar to S. delavayi, but differs in its narrowly elliptic, lanceolate or broadly lanceolate leaves, outer phyllaries that are broadly triangular with irregularly dentate margin, and densely yellowish stipitate glandular stem, leaf blades, and adaxial phyllaries. It is also similar to S. schlagintweitii, but differs in possessing numerous capitula and having adaxially glabrous petiole bases. Color plates, line drawings, a distribution map of S. haizishanensis, photographs of phyllaries and leaf blades, and SEM microphotographs of the adaxial surface of style arms, the leaf blades, the abaxial surface of phyllaries of S. haizishanensis and S. delavayi are provided.  相似文献   

16.
A new species, Tropaeolum sparrei Ståhl (Tropaeolaceae), is described from submontane cloud forest habitat in western Ecuador. It differs from T. papillosum Hughes (the species it resembles most) by having thinner, tomentose stems, smaller, glabrous or subglabrous leaves with the petiole inserted relatively closer to the lower leaf margin, and flowers with uniformly coloured and straight calyx spurs. In leaf shape it is also similar to T. repandum Heilborn, from which it differs in its larger flowers with entirely black petals and blue anthers.  相似文献   

17.
18.
 Leaf aging and senescence in Clusia multiflora H.B.K. was investigated by artificial treatments, such as floating leaf discs on water in darkness, or darkening leaves attached to the parent plant in situ in trees living in a tropical cloud forest. In both cases several parameters modified by age were evaluated such as nitrogen levels, chlorophyll content, succulence and carbohydrates levels. A prolonged senescence (nearly 3 months in floating leaf discs) was observed, contrasting with species such as Heliocarpus americanus (5 days) and Cecropia palmatisecta (20 days), characterized by low values of leaf weight per area, but similar to species with high leaf weight per area and with high levels of organic acids such as Clusia minor and Fourcroya humboldtiana, where acids may act as a reserve of C and energy. After 30 days in darkness C. multiflora leaf samples collected in the field did not show differences in comparison to non-darkened opposite leaves with respect to chlorophyll, titratable protons and carbohydrates, and leaves performed photosynthesis after 2 months in darkness. The effect of age in leaves was evaluated in a gradient of leaves, sampled at different positions from the apex and ranging in age from 15 days to 2 years old. The study of senescence in tropical wild plants is uncommon, but it is important knowledge for understanding foliar development, and response to internal rather than environmental regulation in climates where seasons are not strongly marked as is the case in the tropical mountain forest, where C. multiflora constitutes an important component in the early successional vegetation. Received: 21 October 1996 / Accepted: 12 November 1996  相似文献   

19.
20.
We used path analysis to ask whether leaf position or leaf light level was a better predictor of within-plant variation in leaf nitrogen concentration in five species of rain forest pioneer trees (Cecropia obtusifolia, Ficus insipida, Heliocarpus appendiculatus, Piper auritum, and Urera caracasana) from the Los Tuxtlas Biological Station, Veracruz, Mexico. Three hundred seventy-five leaves on 28 plants of the five species were analyzed for leaf nitrogen concentration, leaf mass per area, and leaf light interception at different positions (= nodes) along a shoot. Mean values of leaf nitrogen concentration ranged from 0.697 to 0.993 g/m2 in the five species, and varied by as much as 2.24 g/m2 among leaves on individual plants. Leaf position on the shoot explained significantly more of the within-plant variation in leaf nitrogen concentration than did leaf light level in four of the five species: Cecropia obtusifolia, Heliocarpus appendiculatus, Piper auritum (branch leaves only), and Urera caracasana. However, individual species differed considerably in the patterns of nitrogen allocation and leaf mass per area among leaves on a shoot. These results suggest that leaf nitrogen deployment in these plants is, in part, developmentally constrained and related to the predictability of canopy light distribution associated with plant growth form.  相似文献   

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