Abstract
Variation in lateral awn length and pulvini development is described for A. pansa and A. gypsophila. The two species are distinguished by lateral awn development. Within each species, forms are based on pulvini development. Three new forms are described (A. pansa f. contracta; A. gypsophila f. gypsophiloides and f. diffusa), A. dissita is reduced to a form of A. pansa, and A. tehuacanensis is considered synonymous with A. pansa f. dissita. Keys, illustrations, and maps are provided.
Resumen
La variaci’on en la longitud de las aristas laterales y el desarrollo del pulv’inulo se registran para A. pansa y A. gypsophila. Las dos especies se distinguen por el tamaño de las aristas laterales. Dentro de cada especie, se presentan formas en base al desarrollo del pulv’inulo. Se describen tres nuevas formas (A. pansa f. contracta; A. gypsophila f. gypsophiloides y f. diffusa), A. dissita es reducida a una forma de A. pansa, y A. tehuacanensis es reducida a un sinonimo de A. pansa f. dissita. Claves, ilustraciones, y mapas son presentados.
This is a preview of subscription content, log in via an institution to check access.
Similar content being viewed by others
Literature Cited
Allred, K. W. 1984a. Morphologic variation and classification of the North American Aristida purpurea complex (Gramineae). Brittonia 36: 382–395.
— 1984b. Studies in the genus Aristida (Gramineae) of the southeastern United States. I. Spikelet variation in A. purpurascens, A. tenuispica, and A. virgata. Rhodora 86: 73–77.
— 1986. Studies in the Aristida (Gramineae) of the southeastern United States. IV. Key and conspectus. Rhodora 88(855): 367–387.
— & J. Vald’es-Reyna. 1995. Novelties and notes in North American Aristida (Gramineae). Novon 5: 209–222.
Beetle, A. A. 1974. Noteworthy grasses from Mexico. Phytologia 27: 441–447.
— 1981. Noteworthy grasses from Mexico, IX. Phytologia 49: 33–43.
D’avila, P. & J. S’anchez-Ken. 1994. Flora del Valle de Tehuac’an-Guicatl’an. Fasc. 3. Poaceae, subf. Arundinoideae, Bambusoideae, Gentothecoideae. Universidad Nacional Aut’onoma de M’exico.
Henrard, J. T. 1929. A monograph of the genus Aristida. Vol. 1. Meded. Rijks-Herb. 58: 1–153.
Hitchcock, A. S. 1924. The North American species of Aristida. Contr. U.S. Natl. Herb. 22(7): 517–586.
Johnston, I. M. 1943. Plants of Coahuila, eastern Chihuahua, and adjoining Zacatecas and Durango, II. J. Arnold Arbor. 24: 373–421.
Trent, J. A. & K. W. Allred. 1990. A taxonomic comparison of Aristida ternipes and Aristida hamulosa (Gramineae). Sida 14(2): 251–261.
Wooton, E. O. & P. C. Standley. 1913. Of new plants preliminary to a report upon the flora of New Mexico. Contr. U.S. Natl. Herb. 16: 109–196.
Author information
Authors and Affiliations
Rights and permissions
About this article
Cite this article
Allred, K.W., Vald’es-Reyna, J. The Aristida pansa complex and a key to the Divaricatae group of North America (Gramineae: Aristideae). Brittonia 49, 54–66 (1997). https://doi.org/10.2307/2807694
Issue Date:
DOI: https://doi.org/10.2307/2807694