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Nonglandular Trichomes Of Californian And Hawaiian Tarweeds, Andrew A. Maclachlan, Sherwin Carlquist

Aliso: A Journal of Systematic and Floristic Botany

The purpose of this paper was to demonstrate the diversity in nonglandular trichome morphology of tarweeds at the ultrastructural level, and to propose categories for the morphologies reported for such trichomes. Using light and scanning electron microscopy (SEM), the authors surveyed 31 species of II genera of tarweeds from California and three genera of tarweeds from Hawaii. Trichome cell wall thickness in the Californian species ranged from 1 to 6 ~μm, whereas in the Hawaiian species trichome cell wall thickness ranged from 1 to 14 ~μm. Based on their surface appearance using SEM, trichomes were grouped into four categories: grooved; …