Structure and Development of Stomata on the Vegetative and Floral Organs in Some Members of Caesalpiniaceae

The structure and development of stomata in 19 species of thefamily Caesalpiniaceae are described. The study is mostly confinedto the leaves, but observations have also been made on othervegetative and floral organs of some species Stomata may beparacytic, anisocytic, anomocytic, and with one subsidiary cell.Occasionally a stoma is diacytic, cyclocytic, or actinocytic.Different types occur individually or may be found side by sideeven on the same surface of an organ. The most prevalent typein all the genera is paracytic except in Caesalpima where itis anomocytic. The development of an anomocytic stoma is perigenous,but those with subsidiary cells are largely mesogenous; rarelyparacytic stomata are mesoperigenous. In spite of diversityof stomata, different types of stomata have similar patternsof development in different organs of the same plant. The presentinvestigation also indicates that the inconstancy of stomatain the family is due to (a) their diversity and (b) an increasein the number of subsidiary cells either by their division orby the neighbouring perigenes becoming subsidiary cell-like.     

Structure and Development of Stomata in Vegetative and Floral Organs of Three Species of Kalanchoe

The structure and ontogeny of stomata in vegetative and floralorgans of three species of Kalanchoe is described. The matureanisocytic stomata are mono-cyclic or completely or incompletelyamphicyclic, rarely paracytic, transitional between paracyticand anisocytic and with a single subsidiary cell. The developmentof all the types is syndetocheilic or mesogenous from organto organ but the mature stomatal apparatus varies from organto organ as regards the number and arrangement of subsidiarycells. Abnormal stoma with a single guard cell and arresteddevelopment were observed on all organs. An abnormal stoma witha single guard cell develops directly from the meristemoid.     

Epidermal Structures and Stomatal Ontogeny in Some Mimosaceae

The structure of trichomes and stomata on leaflets of 21 speciesof the Mimosaceae are described. Non-glandular trichomes inMimosa pudica are of three types: unicellular, with a roundedthick-walled base and a terminal unicellular body, and multicellular.Capitate, clavate, or cylindric, 3–6-celled glandularhairs are observed on leaflets of Mimosa pudica only. Leafletsare amphistomatic in all species except Adenanthera pavonina,Calliandra sp., Parkia biglandulosa, Pithecellobium dulce, andSamanea saman in which they are hypostomatic. Only paracyticstomata are found in Leucaena leucocephala and Mimosa pudica.In the rest stomata are of more than one type. In spite of thediversity, the most frequent type in these species is paracytic.Anisocytic stomata, in all cases, are secondarily derived fromparacytic ones by transverse or oblique wall formation in asubsidiary cell. Similarly some stomata with one subsidiarycell are also secondary derivatives of the paracytic ones becauseof one of the subsidiary cells assuming the form of an epidermalcell. The development has been traced in 14 species and thatof paracytic stomata may be mesogenous or mesoperigenous, thatof stomata with one subsidiary cell mesogenous but anomocyticstomata are ontogenetically perigenous. Occasionally a meristernoidis cut off from one of the subsidiary cells of a paracytic stoma.The organization of a stoma from such a meristemoid has beentraced.     

Variation in the structure and development of foliar stomata in the Euphorbiaceae

The structure and ontogeny of foliar stomata were studied in 50 species of 28 genera belonging to 17 tribes of the family Euphorbiaceae. The epidermal cells are either polygonal, trapezoidal, or variously elongated in different directions and diffusely arranged. The epidermal anticlinal walls are either straight, arched or sinuous. The architecture of cuticular striations varies with species. The mature stomata are paracytic (most common), anisocytic, anomocytic and diacytic. Occasionally a stoma may be tetracytic, cyclocytic or with a single subsidiary cell. The ontogeny of paracytic stomata is mesogenous dolabrate or trilabrate, mesoperigenous dolabrate; that of diacytic stomata is mesogenous dolabrate, whereas that of anisocytic stomata is mesogenous trilabrate; rarely an anisocytic stoma may be mesoperigenous. Hemiparacytic stomata are mesoperigenous unilabrate; tetracytic stomata are mesoperigenous dolabrate and anomocytic stomata perigenous. Abnormalities encountered include four types of contiguous stomata, stomata with a single or both guard cells aborted and persistent stomatal initials. Cytoplasmic connections between the guard cells of two adjacent stomata or the guard cell of a stoma and an adjacent epidermal/subsidiary cell, or both types occurring in a species, were noticed. The stomatal development, distribution, diversity and basic stomatal type with reference to systematics are discussed.     

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.     

Epidermal structure and development of stomata in vegetative and floral organs ofHybanthus enneaspermus (Linn.)F. Muell

The present paper deals with the epidermal structure and ontogeny of stomata in vegetative and floral organs ofHybanthus enneaspermus. The epidermal cells are either polygonal or elongated with straight, sinuous or arched thick anticlinal walls. The surface of the cuticle shows parallel striations radiating from the guard cells or hair bases. Unicellular and uniseriate bicellular trichomes with verrucose margins have been observed on all organs. The mature stomata are anisocytic, paracytic, anomocytic and transitional between anisocytic and paracytic. The ontogeny of anisocytic and paracytic stomata is syndetocheilic or mesogenous, anomocytic is haplocheilic or perigenous, while that of the transitional type is mesoperigenous. Four types of stomata have been observed on all the vegetative and floral organs and their ontogeny from organ to organ of this plant is constant. Stoma with a single guard cell is the result of disintegration of one of the guard cells before or after pore formation. Contiguous stomata are also occasionally noticed.     

Epidermal Structure and Stomatal Development in Some Malvaceae and Bombacaceae

Epidermal structure and development of stomata in 15 speciesof the Malvaceae and two of Bombacaceae are described. The cellsof the epidermis are polygonal, isodiametric, or elongated withthick, straight, arched, or sinuous anticlinal walls and containchloroplasts and abundant druses of calcium oxalate. Cuticularstriations radiating from the guard cells or hair bases arenoticed. Six types of glandular and non-glandular trichomesare seen. The mature stomata are anomocytic, anisocytic, andparacytic in the members investigated of both the families.The ontogeny of anisocytic and paracytic stomata is syndetochelicor mesogenous, while that of anomocytic is haplocheilic or perigenous.An abnormal stoma with a single guard cell is also observed.An increase in number of subsidiary cells in anisocytic stomatais due to the division of the subsidiary cells.     

Structure and Development of Stomata on the Vegetative and Floral Organs of Some Amaryllidaceae

The structure and development of stomata in 10 Amaryllidaceousmembers are described. The study is made on the leaves and floralorgans of Amaryllis belladona, Crinum asiaticum, C. bulbispermum,C. latifolium, C. pratense, Pancratium sp., Polianthes tuberosa,and Zephyranthes atamsco, and on leaves of Agave sp. and Curculigoorchioides. In most of the organs of the different plants studiedmore than one type of stoma occur, even on the same surface.However, the stomata are largely anomocytic in Amaryllis, Crinum,Pancratium, Polianthes, and Zephyranthes, but they are tetracyticin Agave and Curculigo. An increase in the number of subsidiarycells in teracytic, tricytic, paracytic, and stomata with onesubsidiary cell has been noted. It may be due to wall formationin the subsidiary cells or by the neighbouring perigenes assumingtheir form. The range of variation in different types of stomatain each organ has been studied. Abnormal features such as juxtaposedor superimposed contiguous stomata, connections between guardcells of nearby stomata, transformation of meristemoids intoepidermal cells are observed. The development of different typesof stomata in different organs of the same plant is perigenous.The systematic position of different genera is discussed inlight of the present findings. A method of preparing epidermalimprints by the use of Depex, a mounting medium, and white ofan egg is also described.     

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.     

Epidermal Structure and Stomatal Ontogeny in Some Polygonales and Centrospermae

The epidermal structure and ontogeny of stomata in 19 speciesof Centrospermae and two of Polygonales are described. The cellsof the epidermis are polygonal, isodiametric, or elongated invarious directions and arranged irregularly. The anticlinalepidermal walls are thick, sinuous, straight, or arched. Eleventypes of glandular and eglandular trichomes have been observed.Six types of stomata: anomocytic, paracytic, stomata with asingle subsidiary cell, diacytic, anisocytic, and transitionalbetween diacytic and paracytic, have been noticed in the speciesinvestigated. The ontogeny of anomocytic stomata is haplocheilicor perigenous, while that of the other five types is syndetocheilicor mesogenous. Abnormal stomata with a single guard cell, unequalguard cells, aborted guard cells, and arrested development arecommon. Groups of stomata are also frequent but contiguous stomataare rather rare.     

Epidermal Structure and Ontogeny of Stomata in Vegetative and Reproductive Organs of Ephedra and Gnetum

The epidermal structure and development of stomata in vegetativeand reproductive organs of Ephedra foliata and Gnetum ula isdescribed. The epidermal cells are polygonal, isodiametric,or elongated with thick or thin straight, arched, or slightlysinuous anticlinal walls. The cuticle is thin or thick. Papilla-likeunicellular outgrowths are present in Ephedra foliata. The maturestomata are orientated parallel to the longitudinal axes orirregularly. The mature stomata are anomocytic, paracytic, witha single subsidiary cell, cyclocytic, and actinocytic. Arresteddevelopment, contiguous stomata, and stomata with aborted guardcells have been observed. The ontogeny of stomata on differentorgans of these two plants is typically haplocheilic or perigenousbut the stomatal apparatus varies from organ to organ.     

Stomatal Features in the Leaf of Aganosma dichotoma (Roth) K. Schum

Paracytic and anisocytic types of mature stomata are found inthe leaf of Aganosma dichotoma. Stomata with one guard cell,stomata with degenerated guard cells, and contiguous stomataare common. Stomata with arrested pore development are alsofound in certain cases. A single guard cell without any porehas not been designated as a stoma with one guard cell in thepresent investigation. Ontogeny of contiguous stomata have beentraced. Subsidiary cells are, morphologically, just like theircontiguous guard cells. Subsidiary cells may retain their shapeand contents even when their contiguous stoma becomes mature,or may change their shape and lose their contents. They mayor may not divide. Subsidiary cells form a whorl of more thantwo subsidiary cells around a stoma by their divisions. Degenerationof guard cell(s)— their contents and nuclei—havebeen traced. In certain cases guard cells divide forming morethan two guard cells associated to a single pore. Cytoplasmicconnections are found between two guard cells of nearby stomata,and between a guard cell and an epidermal cell. Near the wound,the epidermal cells over the veins become meristermatic givingrise to new epidermal cells but no meristemoid.     

Some Observations on the Diversity of Stomata and Trichomes in Six Species of Dioscorea

Stomata and trichomes are described on the leaves of six speciesof Dioscorea. As many as six types were found in D. bulbiferaand D. oppositifolia, four types in D.hispida and D. wallichii,three types in D. belophylla, but only two types in D. alata.Although there is a diversity of stomata even on the same surface,the predominant type is anomocytic in all the species exceptD. bulbifera in which it is tricytic. Rarely a stoma is alsocyclocytic in D. bulbifera. An increase in the number of subsidiarycells in paracytic, tricytic, or diacytic stomata takes placeby the wall formation in them. Similarly a reduction in thenumber of subsidiary cells of a tetracytic stoma is the resultof lateral subsidiary cells assuming the form of epidermal cells.Abnormalities such as a stoma with one guard cell, degenerationof guard cells, and contiguous stomata are also met with. Theorganization of different types of stomata is studied in D.bulbifera and D. wallichii and shown to be perigenous. Capitateglandular hairs were seen on the leaves of D. belophylla, D.bulbifera, D. hispida, and D. wallichii but non-glandular, uniseriate,3-celled trichomes were observed only in D. hispida.     

Development of Normal and Abnormal Stomata in some Araliaceae

The present investigation describes the ontogeny of normal andabnormal stomata for three species of the Araliaceae. The maturestomata are mostly anisocytic, occasionally paracytic, and rarelyanomocytic. Several aberrent patterns of stomatal developmenthave been noticed in anisocytic stomata and a few in paracyticones. The ontogeny of anisocytic and paracytic stomata conformsto the syndetocheilic or mesogenous type, while that of anomocyticis haplocheilic or perigenous.     

Structure and Ontogeny of Stomata in Some Polemoniales

The ontogeny and structure of stomata in 22 genera and 51 speciesof the Polemoniales are described. Five main types of stomatanoticed are: anisocytic, anomocytic, diacytic, paracytic, andstomata with a single subsidiary cell. Three modes of stomataldevelopment: syndetocheilic or mesogenous, haplocheilic or perigenous,and meso-perigenous or syndeto-haplocheilic are observed. Abnormalitiesseen are: stomata with single guard cells, arrested developmentand contiguous stomata variously oriented. Contiguous stomataresult from adjacently placed meristemoids or readjustment duringmaturation. Stomata with a single guard cell are formed as aresult of degeneration of one of the guard cells before or afterpore formation. The stomatal apparatus varies in different organsof a plant in form, number, orientation and arrangement of thesubsidiary and also the surrounding cells. Three lines leadingto Polemoniales, Boraginales, and Solanales are distinet.     

Morphogenetic effects of various growth substances on the cotyledonary stomata of brinjal and tomato

The effect of different growth substances on the development of normal and abnormal stomata are presented. Anomocytic, paracytic, anisocytic and stoma with a single subsidiary cell are observed. Abnormal developments like persistent stomatal cells, degeneration of guard cells, unusual thickening, unequal guard cells, single guard cells and size and shape of the pore are noticed in various growth substances. The growth substances also affect the stomatal frequency, stomatal index, epidermal frequency and size of guard and epidermal cells in both the plants. The highest meristematic activity is found in MOR 100 ppm in brinjal and in GA 25 ppm in tomato. The largest size of stomata is found in COL 25 ppm in brinjal and in MH 50 ppm in tomato. The same growth substance responds differently in the two plants.     

Structure, distribution and taxonomic importance of foliar stomata in some Indian Amaranthaceae

The structure, distribution and taxonomic importance of foliar stomata in 45 taxa belonging to 19 genera have been studied. In all, six stomatal types have been recognized viz., anomocytic, anisocytic, diacytic, paracytic, hemiparacytic and brachyparacytic. The majority of the taxa are amphistomatic whereas hypostomatic leaves are confined to only three taxa. Stomatal diversity is common but most of the taxa show either dominance or codominance. Stomatal distribution is helpful in distinguishing the three tribes of the Amaranthaceae. The tribe Celosieae shows exclusive presence of anomocytic and anisocytic stomata whereas Amarantheae and Gomphreneae show other stomatal types viz., paracytic and diacytic in addition to anomocytic and anisocytic stomata. Further, the latter two tribes are each distinguishable into two subtribes on the basis of stomata.     

Direct Measurements of Turgor Pressure Potentials of Guard Cells, I.

Measurements were made of pressures applied in subsidiary andguard cells which caused closure and opening of stomatal pores.These pressures were lower than would be expected from plasmolyticallydetermined osmotic potentials of guard cell saps. The pressuresneeded in guard cells to open almost closed stomata were practicallythe same as those required to close open stomata when appliedin adjacent subsidiary cells. Completely closed stomata couldnot be opened by this technique. The implications for the understandingof the mechanism of guard cell deformation, the Spannungsphase,and the pressure potentials of guard cells are discussed.     

Trichomes and stomata,and their taxonomic significance in theUrticales

Structure and ontogeny of stomata and trichomes have been studied in 23 species and 3 varieties of theUrticales. Stomata are anomocytic, more rarely paracytic; anisocytic and sometimes helicocytic and transitorial types are found inUrticaceae andDorstenia, rarely inArtocarpus. The ontogeny of anomocytic and actinocytic stomata is perigenous, of paracytic either mesogenous or perigenous, of anisocytic either mesogenous or mesoperigenous, and of helicocytic and transitional types mesogenous. Among trichomes eglandular unicellular (wide spread), bicellular or uniseriate filiform (Cannabis); glandular capitate with uni- or bicellular (Moraceae, Ulmaceae, Cannabaceae), uniseriate filiform (Ulmaceae) or multiseriate stalk (Cannabis); sunken glands (Artocarpus); uniseriate glandular with uniseriate stalk (Celtis), and stinging emergences (Urticaceae) have been observed. It is concluded that theUrticales represent a natural order with four families:Ulmaceae, Moraceae, Urticaceae andCannabaceae which are distinct but interrelated with each other.     

Stomatogenesis in the genus Hibiscus L. (Malvaceae)

In Hibiscus , stomata are anisocytic, anomocytic, paracytic and tetracytic, the first type being the most frequent and occurring in all plant parts in the ten species studied, whereas the others are scarce and have a limited organographic distribution. The stem, petiole, pedicel, staminal tube, ovary and style are stomatiferous; the leaf-blade, stipule, bracteole and sepals are amphistomatic and petals hypostomatic in the species investigated.
The stomatal types are often homoplastic, the anisocytic being either mesogenous trilabrate or mesoperigenous dolabrate, the anomocytic, mesoperigenous dolabrate or mesogenous trilabrate, and the tetracytic, mesoperigenous dolabrate or mesoperigenous trilabrate. But the typical paracytic stomata (with the subsidiaries completely enclosing the poles) are constantly mesogenous dolabrate and therefore probably indicate mesogenous dolabrate development. Although several patterns of stomatogenesis are encountered in any specific organ, only one of them is found to be dominant. A new subcategory of stomatal ontogeny, mesoperigenous trilabrate, is proposed in Hibiscus. No significant stomatal variation involving reduction in the divisive capacity of the meristemoid has been observed from the vegetative to floral parts; and stomata functioning as hydathodes have not been noticed in the latter, thus indicating that florogenic factors have no effect on the stomata.