Seed Anatomy, Morphology, and Field Biology of Argemone spp (Papaveraceae)

Abstract

Seed ontogeny in Argemone aurantiaca G. B. Ownbey, seed morphology of the eight Texas Argemone species, and the establishment of three selected Argemone species has been investigated.

Ovule primordia are dizonate. The inner integument is initiated before the outer integument. The ovule is anatropous. Just prior to anthesis, the inner integument is composed of three cell layers and the outer integument is composed of two cell layers. The embryo sac follows the Polygonum-type development. Antipodals are enlarged and persistant as described in A. mexicana L. At maturity, the tegmen is composed of one cell layer and the testa is composed of three cell layers. The mature seed is covered by a thick cuticle.

The root systems and soil preferences of A. sanguinea Greene, A. aurantiaca, and A. albiflora Homem. subsp. texana G. B. Ownbey, were contrasted. Seed and capsule production, capsule dehiscence mechanisms and seedling establishment were investigated in the latter two species. Seed viability and germination rate were determined for A. aurantiaca.

An S.E.M. examination of the seed coats of the eight species revealed differences in seed length, micropyle and chalazal morphology, and density of reticulations, papillae, and stomata! apparati among the eight species. Based on these data, a taxonomic key to the seeds of the Texas Argemone species has been developed.