- Blue markers: specimen records
- Yellow marker: type locality, if present
- Red markers: endpoints of range from literature
Prionitis J. Agardh 1851
Thalli erect, 1 or more axes arising from discoid holdfasts. Axes terete below and compressed above, or terete or compressed throughout. Major branches approximately same breadth throughout, dichotomously or irregularly divided. Lateral margins of major secondary branches frequently with numerous peglike to foliar proliferations; branches lying in same plane, appearing pinnate. Surface of thallus smooth. Medulla of densely interwoven filaments. Cortex of small, tightly packed cells in deep rows. Transitional area between medulla and cortex sometimes with stellate cells. In general, medulla twice as thick as cortex (in Carpopeltis bushiae, thickness of medulla equal to that of cortex). Tetrasporangia cruciately divided, isolated in cortex or grouped in small sori. Spermatangia in extensive, whitish, superficial sori covering both surfaces of branches. Carpogonial branches 2-celled, arising in small cluster of sterile filaments; auxiliary cell intercalary, immersed in small, branched cluster of sterile filaments. Connecting filament necessary for transfer of diploid nucleus. Gonimoblasts in groups, modifying thallus externally, borne on internal stalks formed by fused basal cells of gonimoblast. Gonimoblast filaments developing toward surface, nearly all cells but basal ones becoming carposporangia, surrounded by sterile filaments.
Excerpt from Abbott, I. A., & Hollenberg, G. J. (1976). Marine algae of California. Stanford University Press, Stanford, California. xii [xiii] + 827 pp., 701 figs.
