The federally endangered crenulate leadplant, Amorpha herbacea Walter var. crenulata (Rydb.) Isely, is an endemic shrub of the globally imperiled pine rocklands of southern Florida. Crenulate leadplant is near extinction in the wild due to heavy habitat loss, fire suppression, altered hydrology, and invasion by non-native species. This study examined the floral biology and breeding system of the leadplant and factors that may help explain its decline and provide direction for conservation. Protogynous flowers and a high pollen/ovule ratio suggest a reproductive strategy of outcrossing, while a binucleate pollen grain indicates possible gametophytic self-incompatibility. Hand pollinations show that while the leadplant is capable of some self-fertilization, it is significantly more successful in setting fruit when cross-pollinated, and produces a greater percentage of seed when outcrossed. This predominantly self-incompatible species may, therefore, suffer decreased reproductive fitness in its few remnant localities.
Amorpha herbacea var. crenulata