Fairchild expanded its test of whether translocation outside the known historic range of the endangered crenulate leadplant (Amorpha herbacea var. crenulata) could be a viable conservation alternative. In August 2007, we introduced 245 plants into four microhabitats along a pine rockland/transverse glade gradient with similar attributes to historically known and current South Florida occurrences. After one year survival of transplants was best in pineland habitat (92%), while survival in ecotone(73%), grassy glade (75%), and restored glade(66%)was significantly less. As was true in our pilot study, Amorpha does not grow well with heavy competition especially with grasses. Their superior survival in pineland habitats is probably related to lack of competition and slightly higher soil moisture in this habitat.

Although regulatory agencies caution against translocation outside of known historic ranges, when most wild populations and their habitats have been altered or destroyed few viable options may be available for conserving rare plants. To test whether translocation outside its known historic range could be a viable conservation alternative for the endangered crenulate leadplant (Amorpha herbacea var. crenulata) we introduced it into four microhabitats along a pine rockland/transverse glade gradient with similar attributes to historically known and current South Florida occurrences. Survival of transplants was 100% in all microhabitats after one year, but plant growth was highest in the restored glade and ecotone. After 2 years, survival was 80% in all but grassy glade habitat, which had 52% survival. Plants with higher net CO2 assimilation growing on soils with higher pH, less grass cover, and less water content exhibited significantly greater growth. Initial transplants are growing well in the novel habitat outside the historic range, however continued monitoring for new recruits and ongoing site management are essential for long-term success.

Though translocations of rare populations should be considered only as the last resort for species’ conservation, when habitat destruction is imminent, it may be the only means to preserve a species. With over half of the known wild federally endangered Amorpha herbacea var. crenulata (Crenulate lead plant) growing on unprotected land slated for development, preserving this population was critical. We rescued whole plants, cuttings and seeds for an experimental translocation. Into a restored pine rockland, once dominated by Schinus terebinthifolius (Brazilian pepper), we transplanted plants from different sources and of different sizes. Plants used as source stock for the introduction were from an unprotected site, seedlings, and 1-, 2- and 7-year-old plants from Fairchild Tropical Botanic Garden’s ex situ collection. We evaluated which propagule type and source had the best survival, growth and reproduction. After 40 months, overall transplant survival was 71%. Large whole plants, rescued and nursery grown, had the best survival rates (86 and 78%); whereas cuttings had 67% survival and seedlings had only 26% survival. The Restored Site, once nearly a monoculture of S. terebinthifolius, is now dominated by 106 native plant species, including 17 naturally recruited state listed plant species. In addition, one federally threatened snake species was observed on the site. These studies demonstrate that botanic garden collections not only play a vital role in the conservation of species’ genetic diversity, but also can be used as source material for habitat restoration.

In 2021, CPC contracted the Fairchild Tropical Botanic Garden to recollect seed from a population currently held in long term orthodox seed storage as part of an IMLS-funded seed longevity experiment. The National Laboratory for Genetic Resources Preservation will evaluate how germination tested viability and RNA Integrity of seed lots decline over time in storage.

Pollination, propagation and seed storage at Fairchild Tropical Gardens (Garvue 1988).

Fairchild maintains a small ex situ conservation collection of plants, both in the nursery and planted in the garden. Hundreds of seeds from multiple populations (including extirpated ones) have been banked at NLGRP and at Fairchild. Other local organizations, including some native plant nurseries, also maintain small ex situ collections.

Fairchild maintains a small ex situ conservation collection of plants, both in the nursery and planted in the garden. Hundreds of seeds from multiple populations (including extirpated ones) have been banked at NLGRP and at Fairchild. Other local organizations, including some native plant nurseries, also maintain small ex situ collections.

The most critical action needed for the conservation of Crenulate lead plant is to conduct prescribed burns in the fire-adapted, urban habitats in which it grows.  Fairchild will continue with the important actions of population monitoring and seed banking indefinitely.  

Fairchild maintains a small ex situ conservation collection of plants, both in the nursery and planted in the garden.  Hundreds of seeds from multiple populations (including extirpated ones) have been banked at NLGRP and at Fairchild.  Other local organizations, including some native plant nurseries, also maintain small ex situ collections.  

There are two wild populations of Crenulate lead plant in Miami-Dade County totaling approximately 500 individuals.  In addition, there are two populations reintroduced to protected areas, totaling approximately 250 individuals.  One of these reintroduced populations has begun to produce recruits.  Several wild populations of Crenulate lead plant were destroyed or died out in the past two decades.  In 2002, the (at the time) largest population of several hundred plants was destroyed when it was sold to a developer, however many of these plants were rescued for ex situ collection or reintroductions.  Shortly thereafter, a population of <5 plants was lost due to fire suppression and invasive species encroachment, and a similar-sized population was again lost in 2015.  

There are 4 known populations of the taxon, all in Dade County, Florida. Its habitat is restricted and minimal due to encroaching residential and commercial development, fire suppression, and invasion by exotic plants.

Amorpha herbacea var. crenulata is threatened by habitat destruction, invasive species (Schinus terebinthifolius, Neyraudia reynaudiana, Bauhina variegata, Vitis sp.), fire suppression and mowing (Garvue 1988).

Current research summary includes investigating relationships with Mycorrhizae (Fisher 2000). Pollination, propagation and seed storage at Fairchild Tropical Gardens (Garvue 1988).