Temperature, Variation, Flowering and Fertility

Wulff: Triploid Cytology (1959)

Semeniuk: Temperature and Rose fertility (1964)

Takatsu et al. Temperature and gladiolus pollination (2001)

Delp: Heat in Hybridizing Rhododendrons (1980)

Focke: Digitalis hybrids
Another even more remarkable case is that of certain hybrid foxgloves. Koelreuter, Gaertner, and Focke observed that the hybrids of Digitalis purpurea crossed with D. lutea produced, in addition to a more or less constant intermediate form, a number of forms very different in appearance. Focke observed among the hybrids which grew spontaneously from a cross-fertilized capsule that he had neglected to harvest when ripe, a number of aberrant forms, the most remarkable of them resembling in all particulars a different species (Digitalis tubiflorum). All artificially produced hybrids of these two species have been found to be completely sterile to the pollen of the parent species. The hybrids also occur in nature, in which case they are said to sometimes bear seed.

Kettlewell: Temperature effect on pigment; Heliothis peltigera and Panaxia dominula (1944)

Jones, D.F.: Maize and Heat (1947)

Knight: Effects of high temperature on plants (1819)

Highkin: Temperature-Induced Variability in Peas (1958)

Highkin: Vernalization & Heat Resistance in Peas (1959)