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1.
2.
A new species of Rubiaceae, Spiradiclis glabra, is described and illustrated from China. The species is most similar to S. fusca, but differs by having 5–7 pairs of adaxially unconspicuous secondary veins in the leaves, stipules 2–5 mm long, calyx lobes ovate‐triangular, corollas slightly purple–reddish, tubes 13–15 mm long, inside with a pubescent ring of long hairs at the throat, and stamens near the base in long‐styled form. The conservation status of this new species was assessed as ‘Vulnerable’ (VU) according to IUCN.  相似文献   

3.
Most members of Sapindales are characterized by compound leaves, but several genera also (or only) produce simple or unifoliolate leaves. A few genera may bear stipules or pseudostipules. Little is known about the morphological structure and morphogenesis of these types of leaves in Sapindales, but this information is required for comparative and evolutionary studies. Metrodorea is a Neotropical genus of Rutaceae, comprising species presenting compound and unifoliolate leaves, plus heterophylly, together with an intriguing bud‐protecting structure at the leaf base. The aims of the present study are: (1) to examine leaf morphogenesis in Metrodorea and in closely related species (four Esenbeckia spp., Helietta apiculata and Raulinoa echinata); and (2) to improve our understanding of the morphological evolution of leaves in Metrodorea and Rutaceae. Our data show that the hood‐shaped structure at the base of the leaf in Metrodorea, usually interpreted as a sheath, is, in fact, a pair of united stipules, a synapomorphy of the genus. In the species studied, it is possible to recognize two main types of unifoliolate leaf: early unifoliolate leaves and late unifoliolate leaves. We also found that the number of leaflets in the studied species is dependent on the late or early determination of the leaf primordium, and that loss of leaflets may have been favoured by the restriction of space available for development within the cavity formed by the pair of united stipules. © 2015 The Linnean Society of London, Botanical Journal of the Linnean Society, 2015, 178 , 267–282.  相似文献   

4.
A new species, Chamaecrista truncata, from southeastern Brazil, is described, illustrated and compared to its putative closest relative, C. parvistipula. The new species belongs to Chamaecrista sect. Chamaecrista ser. Flexuosae which is characterized by asymmetrical leaflets with palmate venation, quadrangular stems and axillary peduncles. Additionally, the venation pattern of the leaflets and the different types of stipules observed within this series are shown.  相似文献   

5.
Abstract Paeonia decomposita Hand.‐Mazz. subsp. rotundiloba D. Y. Hong is here raised to the specific rank, P. rotundiloba (D. Y. Hong) D. Y. Hong, based on its distinctiveness of four diagnostic characters: number of carpels; height of disk; number of leaflets of the lower leaves, and shape of the terminal leaflets; and unpublished molecular data. Paeonia rotundiloba differs distinctly from P. decomposita in having carpels mostly 3, less often 2 or 4, very rarely 5 (vs. almost always 5, very occasionally 4 or 3), disk 8–15 mm high (vs. 4–9.6 mm), leaflets mostly 19–39 (vs. 29–63) in number, and ratio of length to width of the terminal leaflets 1.09–1.93 (vs. 1.81–2.99).  相似文献   

6.
Shoot development of temperate and tropical members of Berberis s. l. was examined in order to assess: (1) the homology of the spines along the long shoots and the foliage leaves that form on the short shoots; (2) the occurrence of heterophylly and/or heteroblasty in the genus; and (3) the structural correspondence between cataphylls, spines, and foliage leaves. The 1-5-armed spines have been interpreted as modified compound leaves lacking stipules, as a modified lamina (central spine) with stipules (lateral spines), or less often, as transformed branches, or as epidermal outgrowths. On the other hand, the foliage leaves of the short shoots have been interpreted as leaflets of palmately compound leaves. Our results indicate that there are three distinct leaf types per node: (1) Leaves modified in spines spirally arranged in long shoots; (2) foliage, expanded leaves densely arranged in short shoots; and (3) cataphylls protecting axillary buds. The spines are leaf homologs with a clear distinction between the leaf base with stipules, and a laminar portion modified into the 1-5-armed spine; the lateral spines are not stipules as they arise from the marginal meristem of the laminar portion, and not from the leaf base. The foliage leaves also have stipules flanking the leaf base. Both spiny leaves and foliage leaves develop an articulation between the base and the laminar portion. Cataphylls of the short shoots of Berberis s. str. and those of the reproductive short shoots of Mahonia correspond to the entire leaf base, but those of the renewal (vegetative) shoots of Mahonia are spiny and have an odd vestigial pinnately compound lamina. Heterochrony due to ontogenetic truncation caused by the formation of the terminal inflorescence at the apex of the short shoots could be responsible for the lack of petiole/lamina differentiation in the foliage leaves. The spiny long-shoot/foliose short-shoot system of branching in Berberis s. str. appears to be genetically and phylogenetically fixed and not environment-dependent. This represents a clear example of metamorphic heteroblasty sensu Zotz et al. (Botanical Review 77:109–151, 2011) with further occurrence of heterophylly along the short shoots.  相似文献   

7.
Shoot tips of Colophospermum mopane (Kirk ex Benth.) Kirk ex Léonard produce leaves which at maturity are bifoliate and devoid of stipules. Investigation of their early ontogeny, however, shows that these leaves begin as trifoliate structures partially enclosed by their stipules. The latter are fused along their mid regions, forming a tongue-like “connector.” The lower chamber of this stipule pair harbors the apical meristem while the upper compartment enfolds the two lateral leaflets. The terminal leaflet, histologically resembling the stipules, also fulfills a similar function by covering the top portion of its sister leaflets. Anatomically, the shoot apex displays a pendulum symmetry, with rather steep elevation of that internode portion which subtends the newly formed primordium. Some comparisons with the shoot apex of Hymenaea are drawn.  相似文献   

8.
The flexible association of the light harvesting complex II (LHCII) to photosystem (PS) I and PSII to balance their excitation is a major short-term acclimation process of the thylakoid membrane, together with the thermal dissipation of excess absorbed energy, reflected in non-photochemical quenching of chlorophyll fluorescence (NPQ). In Pisum sativum, the leaf includes two main photosynthetic parts, the basal stipules and the leaflets. Since the stipules are less efficient in carbon fixation than leaflets, the adjustments of the thylakoid system, which safeguard the photosynthetic membrane against photodamage, were analysed. As compared to leaflets, the stipules experienced a decay in PSII photochemical activity. The supramolecular organization of photosystems in stipules showed a more conspicuous accumulation of large PSII-LHCII supercomplexes in the grana, but also a tendency to retain the PSI-LHCI-LHCII state transition complex and the PSI-LHCI-PSII-LHCII megacomplexes probably located at the interface between appressed and stroma-exposed membranes. As a consequence, stipules had a lower capacity to perform state transitions and the overall thylakoid architecture was less structurally flexible and ordered than in leaflets. Yet, stipules proved to be quite efficient in regulating the redox state of the electron transport chain and more capable of inducing NPQ than leaflets. It is proposed that, in spite of a relatively static thylakoid arrangement, LHCII interaction with both photosystems in megacomplexes can contribute to a regulated electron flow.  相似文献   

9.
A new species, Zygia nubigena Ståhl, L. Rico & G. P. Lewis (Leguminosae–Mimosoideae), is described from western Ecuador. It is characterized by large and very thick‐walled fruits with coarsely alveolate‐reticulate surfaces, spicate inflorescences, one (less common) or two pairs of pinnae per leaf and 4 or 5 pairs of petiolulate leaflets per pinna. In leaf features, Z. nubigena is similar to Z. steyermarkii (Schery) Barneby & J. W. Grimes from montane forest in southern Ecuador, but differs by having somewhat smaller flowers borne in long, many‐flowered racemes (not 25–30‐flowered capitulae). The fruits of Z. nubigena resemble those of Z. rhytidocarpa L. Rico (Honduras, Guatemala) and Z. megistocarpa (Barbosa) L. Rico (northern Peru), but Z. nubigena differs from both in vegetative and floral characters.  相似文献   

10.
Potentilla jiaozishanensis, a distinct new species of Rosaceae from Yunnan, China, is described and illustrated. Morphologically, it is closely related to P. stenophylla var. stenophylla but clearly differs from the latter by its bidentate leaflets, lanceolate epicalyx‐segments that are longer than the sepals, villose ovaries and achenes. Moreover, the pollen grains of P. jiaozishanensis are markedly different from those of P. stenophylla var. stenophylla in size and shape. The newly described species is endemic to the Jiaozishan Mountains, southwest China.  相似文献   

11.
Cycas dharmrajii L.J.Singh (Cycadaceae), a new species from the Andaman Islands, India is described and illustrated, and its conservation status is assessed. An abnormal branching habit of the giant trunk, its swollen base, often branched, polymorphic aerial roots, medium‐sized leaves, megasporophylls with well‐defined 10–28 paired lateral hook‐like structures and 1–3 pairs of ovules, 2‐schizo‐lysigenous mucilage canals in leaflet, and characteristic pitting on the periclinal walls of the epidermal cells of the leaflets distinguishes it from all previously known species. A key to the species of Cycas from the Andaman and Nicobar Islands is also provided.  相似文献   

12.
Dalea conetensis, a new species from the central part of the State of Durango, Mexico, is described and illustrated. It is referred to Dalea subgenus Parosela sect. Parosela series Versicolores. It is morphologically similar to D. pinetorum var. pinetorum but can be distinguished by its shorter stipules, leaves, bracts, calyx teeth, petals, androecium, fewer and shorter leaflets, and the calyx pubescence.  相似文献   

13.
Two genotypes of the pea (Pisum sativum L.) with wild-type leaves (variety Orlovchanin, Af/Af genotype) and the afila morphotype (aphyllous variety Nord, af/af genotype) were compared in terms of growth performance and hormonal characteristics of different leaf parts and the whole plant. The replacement of leaflets by tendrils in the afila variety led to a reduction in total dry weight and the area of photosynthesizing surfaces. The loss of leaflets was partly compensated for by rapid expansion of stipules at early stages of plant development and by the hypertrophy of tendrils at later stages. The excessive development of stipules in afila plants was paralleled by the increase in IAA and cytokinin level in their tissues. The hypertrophied development of tendrils and chlorophyll accumulation in tendrils of afila plants was correlated with a high IAA and cytokinin content at a low ABA background level. The elevated content of ABA in tissues of wild-type plants was associated with the preferential development of leaflets and a larger transpiratory surface compared with those in the afila form. It is assumed that this feature ensures the turgescence of wild-type plants. The possible involvement of phytohormones in growth and morphogenesis of pea mutants is discussed.  相似文献   

14.
绵刺(Potaninia mongolica Maxim.)隶属于蔷薇科绵刺属,只含有绵刺1种。它以花萼3、副萼3、花瓣3、雄蕊3等性状而区别于蔷薇科任何其它属的植物,有“三瓣蔷薇”之美称。其茎多分枝,具宿存、坚硬而成刺状的老叶柄;叶为三出复叶;小叶革质,顶生小叶3全裂,裂片与侧生小叶同形,全缘,两面具长绢毛;叶柄短、坚硬,宿存;托叶膜质,贴生于叶柄。花单生叶腋,花瓣白色或浅粉红色;雄蕊短于花瓣;子房上位,长卵圆形,密生绢毛,花柱基生。瘦果长圆形,淡黄色,为宿存萼筒所包被。绵刺为强旱生小灌木植物,主要生长于具有薄层覆沙的沙砾质荒漠、山前洪积扇和山问谷地,常形成绵刺群落,是沙砾质荒漠的建群种。  相似文献   

15.
A recessive foliage mutant of Pisum, designated ‘sinuate leaf’ (sil), was found to have two distinct forms of expression, depending on the background genotype. In an af/af background—wherein leaflets are converted to tendrils—sil/sil plants had adventitious tendrils arising from clefts in the distal portion of the stipule. These adventitious tendrils were morphologically modified, just as were the true tendrils on the same plant, by different allelic combinations at the tl locus. In the standard Af background, sil/sil plants had neither incised stipules nor adventitious tendrils, although they did have undulated and somewhat distorted leaflets and stipules. Because mutant expression was variable in an Af background, classification of segregating populations was uncertain. This uncertainty was removed by taking advantange of pleiotropic effects exerted by sil in the presence of one of the wax mutants, wlo, wb, or wsp. Homozygous wlo plants ordinarily have uniformly waxy stipule surfaces, but when the plants were also homozygous for sil the stipule tips were waxless. Conversely, wb/wb and wsp/wsp plants ordinarily have uniformly waxless stipules, but when wb/wb or wsp/wsp plants were also homozygous recessive for sil the stipule tips were waxy. However, sil had no observable effects of any kind on the stipule tips of plants with stipules reduced in size by the action of st/st. By their individual and combined effects, the foliage mutants used in this study revealed developmental relationships among leaf parts not otherwise evident in non-mutant plants.  相似文献   

16.
Fruit crops are regarded as important health promoters and constitute a major part of global agricultural production, and Rosaceae species are of high economic impact. Their culture is threatened by bacterial diseases, whose control is based on preventative treatments using compounds of limited efficacy and negative environmental impact. One of the most economically relevant examples is the pathogen Xanthomonas arboricola pv. pruni (Xap) affecting Prunus spp. The plant immune response against pathogens can be triggered and amplified by plant elicitor peptides (Peps), perceived by specific receptors (PEPRs). Although they have been described in various angiosperms, scarce information is available on Rosaceae species. Here, we identified the Pep precursor (PROPEP), Pep and PEPR orthologues of 10 Rosaceae species and confirmed the presence of the Pep/PEPR system in this family. We showed the perception and elicitor activity of Rosaceae Peps using the Prunus–Xap pathosystem as proof‐of‐concept. Treatment with nanomolar doses of Peps induced the corresponding PROPEP and a set of defence‐related genes in Prunus leaves, and enhanced resistance against Xap. Peps from the same species had the highest efficiencies. Rosaceae Peps could potentially be used to develop natural, targeted and environmentally friendly strategies to enhance the resistance of Prunus species against biotic attackers.  相似文献   

17.
The karyotype analysis and physical locations of 45S rDNA were carried out by means of fluorescence in situ hybridization in three species, and two forms of Sophora, two species of Robina, and one species of Amorpha. S. japonica L., S. japonica L. f. oligophylla Franch., S. japonica L. f. pendula Loud., and S. xanthantha C. Y. Ma. are all tetraploids with 2n = 28. There were four 45S rDNA sites in pericentromeric regions of two pairs of chromosomes in each of them. S. rubriflora Tsoong. is a triploid with 2n = 21, and three sites were located in each satellite of group 5 chromosomes. In R. pseudoacacia L. (2n = 2x = 22), we examined four intensive signals in telomeric regions of two pairs of satellite chromosomes. In R. hispida L. (2n = 2x = 30), there were four other signals in centromeric regions besides those like in R. pseudoacacia. Amorpha fruticosa L. has most chromosomes (2n = 40) among the eight materials, however, there were only six 45S rDNA loci and they laid in centromeric regions, and satellites of three pairs of chromosomes. 45S rDNA is a valuable chromosomal landmark in karyotype analysis. The distribution and genomic organization of rDNA in the three genera were also discussed. __________ Translated from Acta Botanica Yunnanica, 2005, 27(3): 261–268 [译自: 云南植物研究, 2005, 27(3): 261–268]  相似文献   

18.
Summary

Some promising biomass clones traded in Great Britain as Salix x smithiana Willd. (S. viminalis x S. cinerea) are in fact S. x sericans Tausch ex Kern. (S. viminalis x S. caprea) but the major problem discussed is that two distinct willows are masquerading under the same name, S. dasyclados. To avoid confusion it is suggested that S. x dasyclados Wimmer is retained for the hybrid (2n = 57), a female clone and formerly a notable Dutch and English basket willow, whereas for S. dasyclados Skvortsov non Wimmer, a species ranging from the Baltic to Siberia with 2n = 76, the name S. burjatica Nasarov, as suggested by Chmelar, is preferred. The willows distributed and designated Salix aquatica Gigantea by the Danish willows specialist Jensen, which formed the basis of many early biomass trials, are regarded at present as selections of, or very similar to, S. burjatica Nasarov (S. dasyclados sensu Skvortsov non Wimmer). In addition to a higher level of ploidy, they are visually distinguishable from S. x dasyclados Wimm. by their wider and longer leaves, persistent stipules and the existence of male forms.  相似文献   

19.
The host plant, oviposition behavior and larval ecology of Profenusa japonica Togashi are reported for the first time. Adults of P. japonica mated and oviposited on a polyantha rose, Rosa multiflora (Rosaceae), in April. Each female adult laid an egg on the edge of a leaflet. Hatched larvae consumed the parenchymatous layer of leaflets and in so doing created a mine. The larval stage comprised five instars. On average, 70.6% of the total area of a leaflet was consumed by one larva. Female adults of P. japonica laid eggs singly, probably to avoid larval competition for food.  相似文献   

20.
Spiradiclis quanzhouensis, a new species of Rubiaceae from northeastern Guangxi, China is described and illustrated. It is similar to S. umbelliformis, but can be distinguished by its rosulate habit, subglabrous stems, leaf blades that are pubescent on both surfaces, lanceolate purple‐pubescent stipules that are undivided or sometimes bifid in apical 1/3, an inflorescence with 2–4 flowers, lanceolate 4–5 mm long calyx lobes that are purple‐pubescent outside, a salveriform corolla that is light purple‐pubescent outside, a semi‐inferior ovary, and capsules that are light purple‐pubescent with persistent calyx lobes 5–6 mm, in fruit 2 × as long as capsule.  相似文献   

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