Lithospermum longiflorum has cleistogamous flowers and, unlike other species of genus, it is not dimorphic.
Herbarium of Harvard University, | Botanic Garden, Cambridge, Mass.
March 30 1877
My Dear Darwin
Thanks for your note about the dimorphics.
The Lithospermums of § Batschia are dimorphic—as
is well known. But one of them, L. longiflorum (Pentalophus
A. DC.) turns out to bear, later in season (and in some plants from the first?)
smaller and smaller flowers,—of which some must be cleistogenous. Now
of this a long series of the long-flowered state in the
It is the only one that is cleistogenous. Curious, that it should take to this instead of dimorphism
Yours ever | A. Gray