Allozymic and morphological evidence for a progenitor-derivative species pair in Camassia (Liliaceae)

Analyses of morphological and isozymic variability were used to discriminate populations of Camassia angusta from those of C. scilloides. Camassia scilloides had a distinct, earlier flowering period than C. angusta. Populations identified on the basis of differences in relative flowering time showed little morphological and isozymic divergence but could be correctly classified by taxon-specific patterns of variation for these characters. The allozymes of C. angusta were mostly a subset of those of C. scilloides; the latter had nine unique, rare alleles at 10 loci and the former had only two. Camassia angusta, therefore, may be a relatively recent derivative of C. scilloides. While the taxa have diverged little from each other for the characters examined, they appear reproductively isolated and should be maintained taxonomically as separate species.