Conservation genomic ddRadseq data for Hymenocallis henryae, a federally petitioned spiderlily endemic to the Florida panhadle; SNP data of 279 individuals from 19 populations

Hymenocallis henryae is a rare, charismatic spider-lily endemic to the
Florida panhandle. Currently under review to determine if listing under
the Endangered Species Act is warranted, this species has undescribed
genetic diversity, information crucial to the listing process. We
conducted field observations of 21 historic populations across the
species' geographical range and performed genomic analyses of 279
individuals from 19 extant populations. Most populations had fewer than 40
individuals, while populations with >100 individuals were found
exclusively on managed lands. Genetic diversity was uniformly low within
populations (HE: 0.074- 0.093), with low to moderate inbreeding
coefficients (FIS: 0.068-0.431). Genetic differentiation was relatively
low among most populations (FST: 0–0.098), although there was statistical
support for isolation by distance. In addition, we found high genetic
similarity and lack of population structure across the species range.
Clonal propagation through fused bulbs is a common reproductive strategy.
We confirmed current threats (habitat change, residential development,
fire suppression) and identified several coastal populations threatened by
sea level rise. It is recommended to continue with in situ protection and
management as well as establishment of ex situ living collections to
preserve populations most at risk of extirpation from habitat loss and
degradation.