Study Names Three New Species of Lupines in Florida
A newly published study of lupines in Florida names three new species, all of which are endemic.
The rigorous, exhaustive study also raises the rank of one species variation to the species level, a move that may help conservation efforts to protect the species.
Authors Edwin Bridges and Steve Orzell focused on the unifoliate group of the genus Lupinus in Florida for their study published in Phytoneuron. (Unifoliate species have a type of compound leaf that consists of a single leaflet.) This unifoliate-leaved group is also known to be a clade, meaning its members share a common ancestor.
Bridges and Orzell obtained DNA sequencing data of the unifoliate Florida clade of Lupinus using RADseq, short for restriction-site DNA sequencing. RADseq is a relatively new, cost-effective technology that allows for comparisons of populations at the genetic level.
The researchers combined their genetic data with morphologic, geographic and ecologic data — an approach known as “integrative taxonomy” — to identify the range limits of and relationships among the unifoliate Florida clade. Their data came from 596 herbarium collections and field work at more than 300 sites in 35 counties in Florida.
Their findings led them to recognize eight species in the clade, up from what was previously thought to be three to five species in the clade.
The table below summarizes their taxonomic changes. Also pictured is Figure 1 from their publication showing the species’ distribution.
Image of Bridges and Orzell’s Figure 1 courtesy of Systematics of the Unifoliate Floridian Lupinus Clade (January 2024)
“The reclassification of these plants was a welcomed surprise,” said Mark Kateli, president of the Florida Native Plant Society and Cuplet Fern chapter. “We’d noticed a lot of variation among plants being identified as L. diffusus. Some had larger flowers, some had different hues in their inflorescences and some had different leaf spacing. I rationalized the differences were because the plants were responding to the growing conditions in different habitats.”
A Case for Speciation
Members of the unifoliate Florida clade of Lupinus largely grow on inland sand ridges, coastal sand ridges and uplands in the central peninsula. The ridges and uplands formed as Florida’s sea levels changed over time, and they’re generally fragmented and isolated.Bridges and Orzell report that lupines growing in these geographically isolated areas developed characteristics so unique that they call for classification at the species level. Moreover, each of the species is endemic to its respective area.
The central peninsula of Florida in particular has “endemic-rich inland sand ridges,” they wrote.
L. aridorum’s Future
The survival of one of the newly classified species, L. aridorum, is of great concern. The plant has long been considered very rare, with just a few populations growing in Polk and Orange counties in central Florida. For years, a “persistent lack of consensus” on the plant’s classification made it difficult to assess its conservation status.Bridges and Orzell report that L. aridorum’s promotion in rank from a variety of a species to its own species calls for a change in status from “Species Globally Vulnerable” (G3T1) to “Globally Critically Imperiled” (G1) (status ranks per NatureServe). This change in classification could help draw federal and state resources to protect the species.
The study is also likely to raise interest in Florida lupines overall.
“We’re in a new era of native plant systematics and taxonomy,” Kateli said. “With technologies such as large-scale DNA sequencing, we’re able to learn more about the relationships between different native plants, a plant’s conservation status — and the unique place that Florida is in the world.”
Using iNaturalist, author Edwin Bridges assigned the species names to the first two observations below with a caveat: The plants may be a Lupinus “intermediate” that contains both L. floridanus and L. ocalensis genes. That may be the case with the last observation as well.
Lupinus Gallery featuring observations by Cuplet Fern members
Lupinus cumulicola (sandhill lupine)
Polk County
Photo by Mark Kateli
Lupinus aridorum (scrub lupine)
Orange County
Photo by Jennifer Hopton-Villalobos
Lupinus villosus (lady lupine)
Alachua County
Photo by JC Krahling
Lupinus floridanus (Florida lupine)
Geneva Wilderness Area, Seminole County
Photos by Karen Guin
Lupinus ocalensis
Chuluota
Photo by Chelsey Stevens
Lupinus floridanus (or an intermediate with L. ocalensis, per Edwin Bridges)
Geneva
Photo by Karen Guin
Lupinus ocalensis/floridanus
Geneva
Photo by Mark Kateli
Lupinus floridanus
Chuluota Wilderness Area, Seminole County
Photo by Karen Guin
“It's complicated at this site [Chuluota Wilderness Area]! In one DNA analysis, the sample from this population clusters with L. ocalensis and in another analysis it clusters with L. floridanus. Observations from this site are also split some look more like L. floridanus (like this one), and others look more like L. ocalensis. I suspect that this population has genetic material from both sources. L. floridanus is found at Geneva Hill, and L. ocalensis is found in the Econ sandhills, both only a few kilometers from this site.” – Edwin Bridges (comment made on my iNaturalist observation of a lupine in Chuluota Wilderness Area)
by Karen Guin, Cuplet Fern Chapter
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