Saturday, March 30, 2024

Gulf Coast Lupine - Lupinus westianus

Gulf Coast lupine (Lupinus westianus) is a short-lived perennial endemic to the western Panhandle counties of Florida and listed as a state-threatened species.  Like other native members of this genus, it is found in very well-drained sandy and open sunny habitats.  Gulf Coast lupine is most common near the Gulf Coast on relic dunes though its salt toleranance is not well reported.  Most lupines, except sundial lupine (Lupinus perennis), live at most for three years, flowering sparingly during year two and forming large plants that flower expansively in year three.  They persist by reseeding and their seeds survive for many years in the seedbank.  Disturbance can stimulate germination and result in large areas of new plants.

Mature plants reach a height of about 3 feet and can spread to about that distance in width.  The leaves and stems are covered by soft hairs and the leaves are alternate on the stems. Each leaf is unifoliate and without the stipules present in some other Florida species.  The stems are herbaceous in young plants, but become "woody" in older plants. 

Flowering occurs in spring.  The purple to lavender blooms occur on terminal spikes that arise on the multiple stems.  Like other lupines, there is a distinct keel above the fused lower lip. The keel is marked by a deeper purple patch that extends from the tip to the throat.  Plants in bloom are very showy.  Pollination is likely performed primarily by large-bodied bees, though I have no personal observations of that.  The pollinated flowers produce the typical oval seed pods and these are quite hairy.

Florida's native lupines (with the exception of sundial lupine) are notoriously difficult to propagate for commercial or restoration production though they are in high demand for such purposes. Though seeds are not difficult to germinate without special scarification/stratification, the seedlings form complex relationships with soil microbiota and they are very difficult to keep them alive for any appreciable period of time in containers.  They also are difficult to grow out via direct seeding unless the proper soil conditions already exist for them.  For these reasons, Gulf Coast lupine is not propagated by any of the nurseries affiliated with FANN - the Florida Association of Native Nurseries, or by others. Its conservation is the target of the Center for Plant Conservation and its future rests largely in protecting coastal dune properties within its range from development and by wise land management.

All of the photos in this post were taken by my friend, Floyd Griffith, and used by permission, except the comparision one which was produced by Edwin Bridges, also used by permission.

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