Virescent Chilicothe [Marah macrocarpus (Greene) Greene]

I photographed the virescent and normal forms of Chilicothe in the Spring at Casper's Wilderness Park in southern California. When I returned a few months later, there was no sign of the virescent form or any dead vines. This may be an instance of temperature dependent virescence like the mutant maize characterized by E. S. Robertson and I. C. Anderson in 1961. In that case homozygotes were normal green at 37°C but virescent at 20°C.

The double flowered Stocks (Matthiola incana) is another example. When the seedlings are grown at low temperatures some will turn pale. Only these will bear double flowers because the "gene" for virescence is linked to that for doubling.

A virescent tobacco grown in Kentucky. In the early season, the plants look like ordinary tobacco. Around mid-summer, though they produce new leaves that are yellow. Subsequently, the older leaves lose their chlorophyll. At harvest time, only a few of the lower leaves remain mostly green.

A protea with virescent leaves serving as part of the floral display. Apr 21, 2003, Golden Gate Arboretum

Other examples: