A monographic revision of Selaginella P. Beauv. subgenus Heterostachys Baker in Central and South America.
Item
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Title
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A monographic revision of Selaginella P. Beauv. subgenus Heterostachys Baker in Central and South America.
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Identifier
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AAI9530923
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identifier
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9530923
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Creator
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Valdespino, Ivan Alberto Quintero.
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Contributor
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Chairman: John T. Mickel
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Date
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1995
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Language
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English
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Publisher
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City University of New York.
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Subject
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Biology, Botany
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Abstract
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A monographic revision of Selaginella subg. Heterostachys in Central and South America was undertaken, based on comparative gross morphological characters of herbarium specimens, and on spore morphology and phytochemical studies. As a result 31 species of Selaginella are classified in subg. Heterostachys in the area of study. Of these, four are newly described (S. gynostachya, S. hyalogramma, S. karowtipuensis, and S. prolifera), a new variety is proposed within S. sobolifera (S. sobolifera var. arcana), as well as a change of status for S. pearcei (as S. moritziana var. pearcei). The synonymy of the species is reviewed and updated. The putative relationships of the species recognized are discussed and a key to separate them is provided.;Spore morphology study indicates that sculpturing and microstructure patterns of both megaspores and microspores are taxonomically useful characters to distinguish species, particularly when traditional morphological characters fail to clearly separate them.;Study of biflavones in selected species indicates that Selaginella is characterized by the presence of robustaflavone, in addition to amentoflavone and hinokiflavone. The biflavonoid patterns of homophyllous and heterophyllous species were similar. No biflavones were found to help characterize subg. Heterostachys. Additionally, the flavonoid profile of species in series Articulatae was characterized by biflavones rather than by simple flavones as reported by Somers (1978).;Subgenus Heterostachys can be defined by the following syndrome of characteristics: (a) lax, flattened, dorsiventral strobili; (b) dimorphic sporophylls; (c) the largest, dorsal sporophylls laterally spreading, located in the same plane as the median leaves, with an adaxial laminal flap, and part of the upper (abaxial) epidermis green, composed of polygonal to rounded cells, except for the portion that forms part of the laminal flap, where the epidermis is hyaline to greenish hyaline, composed of elongate and sinuate cells; (d) the smaller, ventral sporophylls ascending, located in the same plane as the lateral leaves, without a developed adaxial flap, and with the epidermis of both surfaces frequently hyaline or greenish hyaline, composed of elongate and sinuate cells; and (e) axillary or ventro-axillary rhizophores.
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Type
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dissertation
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Source
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PQT Legacy CUNY.xlsx
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degree
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Ph.D.
