NUTLET SCULPTURING IN SCUTELLARIA SECT RESINOSA (LAMIACEAE) AND ITS TAXONOMIC UTILITY

Nutlet sculpturing of 22 taxa of Scutellaria sect. Resinosa, represent ing 18 of its 19 species, and the monotypic genus Salazaria was studie d by scanning electron microscopy (SEM). The nutlets of sect. Resinosa , while remarkably variable among themselves, differed from hypothetic ally closely related sections in lacking circumferential banding: and sessile glands. Species could be grouped by surface sculpturing into s eemingly meaningful phenetic clusters. Scutellaria potosina var. platy phylla was sufficiently distinct micromorphically so as to be elevated to specific status as Scutellaria platyphylla comb. and stat. nov. Th e significance of nutlet microcharacters within sect. Resinosa is disc ussed, especially as compared to closely related sections. The genus S alazaria had nutlet sculpturing quite different from all taxa belongin g to sect. Resinosa.