Micromorphological observations on leaf and pollen of Capparis L. sect. Capparis (Capparaceae)

Sect. Capparis is represented by a single species, Capparis spinosa L., divided into several intraspecific taxa showing plesiomorphic features and disjunct distributions in the Old World. Leaf surface and pollen features were investigated in the whole group by SEM and light microscope observations. The section is characterized by simple hairs, a reticulate to undulate cuticle, anomocytic stomata surrounded by a peristomal rim, and trizonocolporate, prolate pollen grains. The characteristics of the indumentum appear constant, while the studied taxa are fairly differentiated with respect to cuticular patterns and dimensions of the stomata, and show slight differences in pollen size and exine surface. This micromorphological evidence, coupled with other phenotypic features, supports the placement of this section at the base of the genus Capparis in the paleotropical area. Considering the striking geographic disjunction and symplesiomorphies of the group, its biogeographical and systematic aspects are also discussed.     

Osservazioni Sulla Maggiorana (Origanum Majorana L.) in Veste di Pianta Coltivata

Abstract

Stomatal features and ontogeny of stomata of 11 ornamental taxa of monocotyledonous families with Agavaceae (1 species), Amaryllidaceae (1 species), Araceae (3 species), Cannaceae (1 species), Commelinaceae (3 species), Liliaceae (1 species), and Musaceae (1 species) have been studied. Features like stomatal area, leaf area occupied by stomata and per cent leaf area occupied by stomata are reported for these taxa for the first time.     

Stomata in some species of genus <Emphasis Type="Italic">Arum</Emphasis> from the Eastern Slavonia and Baranya region

Types and the number of stomata in the following Arum species: Arum italicum Mill., Arum maculatum var. maculatum L. and Arum maculatum var. immaculatum L., Arum alpinum var. pannonicum Terpo. and Arum alpinum var. intermedium Schur. in three different locations in Zablaće, Normanci and Bilje were investigated. The most prevalent stomata type at both upper and lower epidermis for each Arum species was mostly stomata type paracytic, followed by hexacytic, tetracytic or brachyparacytic as far as locality is concerned. Helicocytic type was more prevalent in Arum alpinum var. pannonicum Terpo. and Arum alpinum var. intermedium Schur. at Bilje. Other stomata types were very rare. A striking regularity in the occurrence of stomata types was not found within a single species. Some stomata types, however, were found either at adaxial or abaxial epidermis or were not present at all. The number of stomata per square mm varied from 25 to 651. A statistically significant difference in the number of stomata per square mm at upper and lower epidermis among Arum species was determined in locations Zablaće and Normanci, whereas no statistically significant differences were found in location Bilje.     

Comparative morphology of the leaf epidermis in the genera Codonanthe (Martius) Hanstein and Nematanthus Schrader (Gesneriaceae)*

The leaf epidermis of 14 species ofCodonanthe and 10 species of Nematanthus has been examined. Species of Codonanthe section Codonanthe are geographically restricted to south-eastern Brazil, and are diploid. They possess multicellular-uniseriate nonglandular trichomes, glandular trichomes with a four-celled head and a short body, anisocytic stomata and lack extrafloral nectaries. Species of Codonanthe section Spathuliformae and Codonanthe subgenus Codonanthella are distributed from southern Mexico through Central America to north-western South America and are tetraploid. They possess unicellular non-glandular trichomes (except C. caribaea), glandular trichomes with a two-celled head (except C. caribaea) and a short body, anisocytic stomata and extrafloral nectaries (except C. caribaea). All Nematanthus species are distributed in south-eastern Brazil and are diploid (N=8). Six species of Nematanthus consistently have multicellular-uniseriate nonglandular trichomes, glandular trichomes with a four-celled head and a short (unicellular) or long (multicellular) body, anisocytic stomata and lack extrafloral nectaries. Four species of Nematanthus have multicellular-uniseriate non-glandular trichomes, glandular trichomes with a head of more than four cells and a short body, anisocytic and helicocytic stomata and lack extrafloral nectaries.     

Structure,ontogeny and taxonomic significance of trichomes and stomata in some Capparidaceae

The present work embodies epidermal structure, structure and ontogeny of stomata in five genera embracing sixteen species of the Capparidaceae namely Cleome (8 species) Capparis (5 species), Cadaba (1 species), Crataeva (1 species) and Maerua (1 species). The epidermal cells are polygonal, isodiametric or elongated arranged irregularly, with evenly or unevenly thickened, sinuous, straight or arched anticlinal walls. Two main types of trichomes: glandular (four types) and eglandular (five types) are noticed. The stomatal types include cyclocytic, triacytic, staurocytic, tetracytic, anomocytic, anisocytic, paracytic and with a single subsidiary cell. The ontogeny of stomata with a single subsidiary cell is perigenous or mesoperigenous, of paracytic mesoperigenous or mesogenous, of anisocytic is mesoperigenous or mesogenous, while that of the other types is perigenous. Abnormalities observed are: single guard cell; aborted guard cells; complete or incomplete division of guard cells; contiguous stomata; giant stomata and cytoplasmic connections. The present observations do not support the separation of Cleomaceae from the Capparidaceae.     

A phylogeny of Cariniana (Lecythidaceae) based on morphological and anatomical data

Cariniana as previously circumscribed is a genus of 16 species restricted to neotropical forest habitats on well-drained sites. A phylogenetic analysis of the genus based on 33 morphological and anatomical characters was undertaken. The results show that Cariniana consists of two clades: the Allantoma/Cariniana decandra clade includes Allantoma lineata and seven species of actinomorphic-flowered Cariniana and is characterized by 5-merous flowers, carnose petals, incurved petal apex, scarcely lobed calyces, eucamptodromous secondary veins, dichotomizing venation, and poorly developed areolation; the C. legalis clade is made up of nine species and is characterized by an obliquely zygomorphic androecium, reticulate tertiary venation, and anomocytic stomata. The actinomorphic-flowered Cariniana are more closely related to the monotypic Allantoma lineata than they are to the species of the C. legalis clade. In order to reflect these relationships, Cariniana is divided into two genera: species in the C. legalis clade, which includes the generic type C. legalis, remain as Cariniana while species of Cariniana in the Allantoma/Cariniana decandra clade are transferred to Allantoma. The following new combinations are proposed: Allantoma decandra, A. integrifolia, A. kuhlmannii, A. pluriflora (a nomen novum for Cariniana multiflora because Allantoma multiflora is a synonym of Couratari multiflora), A. pachyantha, A. pauciramosa, and A. uaupensis.     

A new combination in Aulonemia (Poaceae: Bambusoideae: Bambuseae) based on floral analysis, anatomical features, and distribution

Recent bamboo collections from Brazil, and the study of specimens from several Brazilian herbaria revealed that the species described as Eremocaulon setosum, subtribe Guaduineae, in fact fits within the Arthrostylidiinae genus Aulonemia, based on floral and anatomical characters. Several characters found in this species, such as paniculate determinate synflorescences, solitary spikelets, an abaxial marginal green stripe on the foliage leaf blades, absence of stomata on the entire adaxial side of the leaf blade, and intercostal fibers in the mesophyll are typical features of the subtribe Arthrostylidiinae. The new combination Aulonemia setosa is here proposed, an epitype is designated, and a broader distributional range of this species is documented.     

Application of epidermal morphology to taxonomic delimitations in the genus Jatropha L. (Euphorbiaceae)*

SEM examination of the epidermis of mature leaves of 37 species in the ten sections of Jatropha (Euphoi-biaceae) has provided information consistent with an earlier revision of the genuS. All species examined show basic paracyic stomata, excluding J.fremontioides which has anisocytic stomata. Subgenera are well demarcated by presence of true paracytic stomata in subgenus Curcas and hrachyparacytic stomata in subgenus Jatropha. The two subgenera can also be distinguished by the presence of smooth hairs in subgenusJatropha and verrucose hairs in subgenus Curcas (except in section Curcas).Uniseriate, inulticellular hairs occur only in the three most advanced.closely related.sections (Jatropha, Collenucia and Spinosae) in subgenus Jatropha.Similarities and dissimilarities of cuticular ornamentations, shape of the epidermal and vein cells and direction of anticlinal walls can be used as distinguishing characters, usually significant at the species level.     

Observations on the cotyledonary and hypocotyledonary stomata and trichomes in some Caesalpiniaceae with a note on their taxonomic

The structure and ontogeny of stomata on cotyledons and hypocotyls and the trichomes on hypocotyl are accounted for in eighteen species of Caesalpiniaceae. Trichomes are eglandular, bi- rarely tri-celled, smooth walled or walls wavy with cuticular striations or tubercles. Anomocytic, haplocytic, paracytic, diacytic, transitional, tetracytic, tricytic and cyclocytic stomata occur in different combinations even on the same surface of the cotyledon. In all, there are fourteen combinations. Inspite of the diversity, the most frequent type is anomocytic in most of the species and paracytic in some species of Cassia and Delonix (abaxial) but rarely it is haplocytic or anisocytic. In hypocotyls it is anomocytic. Ontogenetically anomocytic, tetracytic and cyclocytic stomata are perigenous, whereas other types are mesogenous or mesoperigenous. There is an increase in the number of subsidiary cells by their division or the neighbouring perigenes assuming their shapes. About eight such types are described. A pair of stomata has a common subsidiary cell. Twelve types of guard cell and stomatal approximation abnormalities are described. A range in the number, size and shape of the nuclei in guard cell are recorded. Megastomata (giant stomata) are observed in Parkinsonia and Tamarindus. The taxonomic significance of the stomata is also discussed.     

Species of the genus Quercus in Italy: Characterization by means of leaf surface observation

Abstract

We propose a study of the main species belonging to the genus Quercus in Italy, characterized and identified by means of leaf surface observation, with special attention devoted to waxes, trichomes and stomata. Comparing our results with the classification proposed by SCHWARZ (1984), we find that species belonging to Schwarz's subgenus Quercus are recognizable because their waxes are structured in vertical scales; the two other subgenera (Sclerophyllodrys and Cerris) present smooth wax structures, their distinctive feature being the shape of the stomatal rima, which is roundish in Sclerophyllodrys and elliptical in Cerris. The study characterizes Quercus pubescens Willd. and Quercus petraea Liebl. by analyzing some morphometric traits; but the authors feel that further research is needed on these critical taxonomic entities. Lastly, the study examines forms of was degeneration correlated to the phenomenon known as oak decline.     

Leaf epidermal micromorphology of Cercis (Fabaceae: Caesalpinioideae)

The micromorphology of leaf epidermal cells and stomata of all eight species and one form (11 samples) of Cercis were observed by scanning electron microscopy and light microscopy. Both the adaxial and abaxial epidermal cells are polygonal or irregular in shape; the anticlinal walls are straight and arched or undulate. Two types of stomata, which occur only on the abaxial surface of the leaves, are found in the genus. The atypical paracytic type is present in only one species, Cercis chingii, and the anomocytic type is present in all other species. Interspecific differences are minor in the genus with regard to leaf epidermal characters, except for C. chingii, which is characterized by atypical paracytic‐type stomata, a two‐lipped outer stomatal rim, the highest stomatal density and undulate and densely pitted anticlinal walls in the adaxial epidermis. © 2008 The Linnean Society of London, Botanical Journal of the Linnean Society, 2008, 158 , 539–547.     

Anatomical changes and evolutionary trends in the foliar epidermis of extant and fossil Euro-Mediterranean oaks (Fagaceae)

The differentiation of foliar epidermis structures, cuticles, stomata, and indumentum of most of the extant Euro-Mediterranean taxa ofQuercus have been studied by light and scanning electron microscopy, and compared with other genera and fossil material. Results allow the recognition of the subgg.Sclerophyllodrys, Cerris andQuercus, and of various sections and even individual species. The cyclocytic stomata type, regarded as plesiomorphic, is found in the geologically oldest representatives of the familiy (Dryophyllum, resp.Eotrigonobalanus) and in the relatively old, evergreen to semi-evergreen species ofQuercus subgg.Sclerophyllodrys andCerris. These taxa also have relatively thick and smooth cuticles. Anomocytic stomata, thinner cuticles and the presence of crystalline wax flakes are regarded as apomorphic features and characterize the deciduous taxa of subg.Quercus. These changes are interpreted as ecological adaptations to the changing climates from the Tertiary to the present. An analysis of the various character combinations found in macrofossils and the often poor species separation inQuercus suggest that hybridization has played a major role in the evolution of the Euro-Mediterranean oaks.     

Responses of four succession tree species in low subtropics to enhanced UV-B radiation in the field

The tested tree species included pioneer species Acacia mangium, early succession stage species Schima superba, mesophyte intermediate-succession species Machilus chinensis, and shade-tolerant plant or late-succession species Cryptocarya concinna which occur in the lower subtropical forest community. A comparison with the current ambient level of UV-B radiation (UV-B) showed the leaf net photosynthetic rate (P _N), transpiration rate (E), and stomatal conductance (g _s) of the four species ranged from significantly decreased to no significant change. Additionally, the thickness of palisade and mesophyll in leaves of four tree species were decreased sharply by enhanced UV-B. The thickness of spongy parenchyma in leaves was also decreased except for M. chinensis. UV-B increased the leaf width of A. mangium but its leaf length, leaf thickness, and dry mass per unit area were not affected. Significantly increased stomata width was observed in A. mangium leaf epidermis in response to UV-B. Significantly decreased stomata width and significantly increased stomata density of leaf abaxial epidermis in M. chinensis were also observed. The stomata density of abaxial epidermis of C. concinna was remarkably increased by enhanced UV-B. The height and branch biomass of A. mangium and the height of S. superba were reduced visibly by enhanced UV-B. The four plant species could be classified into three groups of UV-B sensitiveness by hierarchical cluster analysis. A. mangium was sensitive to enhanced UV-B, while C. concinna showed more tolerance.     

海南七仙岭7种卷柏属植物的微观形态与生境间的关系分析

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。     

THE CUTICLE OF DREPANOPHYCUS SPINAEFORMIS,A LONG-RANGING DEVONIAN LYCOPOD FROM NEW YORK AND EASTERN CANADA

The presence of paracytic stomata and paired guard cells on specimens presumed to be Drepanophycus spinaeformis Göppert from eastern Canada and New York State supports the conclusion of Banks and Grierson that the species is not a reliable index of Lower Devonian strata. The interpretation of stomatal morphology demonstrates that the species lived in Early, Middle, and Late Devonian time and that slender specimens are distinct from zosterophylls such as Sawdonia that had anomocytic stomata and a single guard cell. Knowledge of the stomata also permits a reinterpretation of the stomatal apparatus as first described by Lang. Siegenian specimens of the genus apparently represent the oldest occurrence of paired guard cells and of paracytic stomata.     

The value of leaf cuticle characteristics in the identification and classification of Iberian Mediterranean members of the genus Pinus

This study reports the value of leaf cuticle characteristics in the identification and classification of Iberian Mediterranean species of the genus Pinus (P. nigra subsp. salzmannii, P. pinaster, P. pinea and P. halepensis), with the aim of using these characters to identify isolated cuticles and stomata in palynology slides. Preparations were made of the cuticles of pine needles belonging to one natural Iberian population of each of the above species. A number of epidermal morphological characteristics were then recorded with the aim of distinguishing these species from one another. The structure of the stomatal complex (the shape and arrangement of the subsidiary cells) was different in each species. The aperture of the epistomatal chamber was significantly smaller in P. pinea than in the other species examined, and the variables recorded for the thickening of the guard cells provided relationships that clearly distinguished all four taxa. The width and length of the stomata and the upper woody lamellae, the central distance between the external limits of the medial lamellae borders and the length of the stem were the most useful variables in this respect. The present results contribute to the ongoing discussion regarding the taxonomic classification of the members of Pinus, and provide valuable clues for the identification of Iberian Mediterranean pine species from small pine needle fragments or isolated stomata. After validation of the present results for multiple populations, these results could also be used to help identify fossil leaf macroremains and the scattered/isolated stomata commonly observed in palaeopalynological samples. © 2009 The Linnean Society of London, Botanical Journal of the Linnean Society, 2009, 161 , 436–448.     

Zur Frage der Überlebensstrategien von Pflanzen in der subnivalen Stufe des Kaukasus

Abstract

On survival strategies of plants in the subnivale belt of the Caucasus. - In the higher part of the Caucasus (Elbrus Mountains, 3500 m) a small phytochore has been investigated, particularly protected by its position being surrounded with big rocks and characterized by few species and distant patches of plant growth. The ecophysiological measurements have shown that the plants are covered by a thin stratum of ice and their surface warms up only during late morning; a short, evident maximum follows at noon. The single species groups can be distinguished on behalf of their plasticity of the stomata and diffusion resistence. It can be assumed that plants are able to avoid waterstress considering that the intense heat ends up in the non compact gravel substrate.     

Adattamenti fisiologici alla vita « aerea » nel genere Tillandsia

Abstract

Physiological adaptations to « aerial » life in the genus Tillandsia.—Ten « atmospheric » Tillandsia species, with different degree of adaptation to drought, were investigated to verify the occurrence of CAM and to determine their daily transpiration pattern.

Most of the species were collected during the Botanical Expeditions of the Accademia dei Lincei in Latin America in 1969 and 1971. All species had been maintained in the greenhouse of the Naples Botanical Garden during the winter months and in the open air during the warmer months, previous to experiments. The diurnal cycle of transpiration, the malic acid content and cell sap pH of the leaves were studied under outdoor conditions. Curves of malic acid and pH variations typical of CAM have been obtained for all the examined species. Moreover, the transpiration data indicate that stomata are open at night. The rates of transpiration appear to be extremely low. The highest transpiration rates refer to the species of the relatively moister habitats, the lowest to the more xeric species. Results indicate that CAM and low rates of transpiration are ecological adaptations to extremely dry habitats.     

STOMATA ON SEEDS AND FRUITS OF BAUHINIA (LEGUMINOSAE: CAESALPINIOIDEAE)

Seeds of 45 species of Bauhinia (Leguminosae: Caesalpinioideae) were studied by scanning electron microscopy. Seeds of eight species have stomata which are mostly normal in appearance but lack subsidiary cells and are slightly recessed. Varying degrees of distortion or obscuring cuticular deposits were found in some species. This is the first unambiguous report of stomata on seeds of Leguminosae. Fruits of two of the eight species were also examined. Raised stomata with conspicuous subsidiary cells were found only on the outer pericarp surface.     

Surface features of the leaves ofBalanophoraceae — A family without stomata?

Both adaxial and abaxial leaf surfaces were searched for stomata inBalanophora elongata, B. fungosa, Hachettea austro-caledonica, Langsdorffia hypogaea, Lophophytum mirabile subsp.mirabile, Scybalium jamaicense, andThonningia sanguinea (Balanophoraceae). Neither stomata nor guard cells were observed. The epidermal surfaces of these species are extremely diverse with respect to cell shape, cell size, and surface ornamentation, these features providing valuable systematic criteria.