Hybrid swarm analysis in Amsinckia: a study of a naturally occurring hybrid swarm involving Amsinckia intermedia F. & M., A Eastwoodae macbride and A. Lycopsoides lerm

All four weedy species of the Muricatae section of the genus Amsinckia are widespread throughout California and often exist sympatrically commonly colonizing the same site. Amsinckia Eastwoodae Macbr., A. intermedia F. & M., A. lycopsoides Lehm, and A. Menziesii (Lehm) Nels. &. Macbr., may evidence morphological variation between populations at different sites, but yet be quite uniform in a single locality (Ray and Chisaki, 1957c.) . A. Eastwoodae is normally an outcrossing species. The prevailing mode of reproduction is self-pollination in A. intermedia, A. lycopsoides and A. Menziesii, but there have been occasional occurrences of apparent hybridization in nature between A. intermedia x A. lycopsoides, and A. intermedia x A. Menziesii (Ray and Chisaki, 1957c). In Fresno County, an instance of natural hybridization apparently involving A. intermedia x A. lycopsoides x A. Eastwoodae provided an opportunity to analyze a complex hybridizing population using morphological, cytological, and biochemical criteria.