Zur Genetik und Systematik der Amoena-Gruppe der Gattung Godetia

RAPID EVOLUTION IN CLARKIA

“…These hybrids had petals with both a basal and central spot like the artificially produced F 1 hybrids and were apparently sterile. Visibly good pollen 2 was 2.8 per cent in the plant examined, which is comparable to that of F 1 hybrids grown in the garden (Hiorth, 1942).…”

“…The distribution of C. amoena extends northward to Vancouver Island. the two species are indistinguishable except by test crosses. The specific status of these two taxa is shown, however, not only by the extensive study of their hybrids by Hiorth (1942Hiorth ( , 1947 and Hakansson 1 (1947), but also by sympatric occurrence in nature. Only one mixed colony has been found (on the road to Meadow Club, 1.5 miles south of Fairfax, Marin County, Raven 11002, 11003, 11004) and at this site C. rubicunda was far more abundant than C. amoena.…”

“…Genomes of six chromosomes, rather than the normal seven, have been found in five populations in central and northern California (Hiorth, 1948). These genomes are the result of translocations whereby most of one chromosome has been transfered to others followed by the loss of a relatively inert chromosome remnant (Hakansson, 1946).…”

“…For example, in a progeny grown from seeds collected at Shelter Cove in Humboldt County, Hiorth (1942) Lewis and Lewis, 1955). All other arrangements found in C. amoena are apparently local and are found primarily, and in some cases exclusively, as heterozygotes.…”

THE ORIGIN OF THE ALLOTETRAPLOID CLARKIA GRACILIS

“…Hiorth ( 1941) suggested on morphological grounds that C. arcuata might be the other parent of C. gracilis. Later, Hakansson (1946) was able to exclude the possibility that C. arcuata might be the second parent of C. gracilis with cytological evidence.…”