Cypripedium flavum MidAtlantic 2024

[Clark Thomas Riley]

A very warm Spring is pushing Cyps into early bloom here in MidAtlantic Maryland. Excellent growth of Cypripedium Christian — should be in bloom next week. All my clones of Cypripedium pubescens are open now. New this year are Cypripedium acaule, nursery propagated from Carnivorous Plant Nursery here in Maryland, and Cypripedium flavum from Hengduan Mountain Biotechnology Ltd. The latter is an upland species from Western China. It is closely allied to Cypripedium reginae, with which it was once confused based on herbarium specimens. Unlike reginae, it would appear to enjoy a much drier habitat. Not sure what it's going to think of Baltimore's summer swelter. I've planted it among thriving Cypripedium pubescens. I'll keep everyone posted.
I will be attempting hybrids (acaule x formosanum) — a remake of Cypripedium Promises, (pubescens x acaule), and (pubescens x Christian) — searching for a Sophronitis-red Cypripedium.

 

[KyushuCalanthe]

It will be interesting to see how C. flavum does in your hot summers. A true scarlet flowered Cyp would be amazing.

 

[tnyr5]

Red might be possible, if you crossed to irapeanum and the like, but you might get impossible hybrids, or it might wash the flowers white (or both...probably both...)

 

[Clark Thomas Riley]

My thinking on the red is that Cypripedium Christian (shanxiense x macranthos ssp. hotei-atsumorianum) has the yellow base pigment from shanxiense in half its genome. As noted, the hotei-atsumorianum suppresses the yellow expression in the F1 while imparting a heavy expression of the anthocyanins. In crossing Christian with the deep yellow pubescens, hopefully we can pick up the anthocyanins without the yellow suppression. Yellows would potentially come from the shanxiense grandparent and the pubescens. Regardless of the exact outcome (assuming the cross takes AND I can get it flasked), we will have some experience on yellow inheritance. The red expectations are based on Sophronitis coccinea (type and flava) and Phragmipedium besseae (type and flava) where F1 yellow suppression is well documented but oranges and scarlets are available in subsequent generations.