Tuesday, July 14, 2015

Golden Crest (Lophiola aurea) - Coastal Plain Endemic with strange "disjunct" distribution

Lophiola aurea, Brunswick Co, North Carolina
June 3, 2015

Golden-Crest (Lophiola aurea) is endangered in North Carolina where it is known from only a handful of sites in the extreme southeastern coastal plain. The species is entirely absent from adjacent states of South Carolina and Virginia but populations reappear both further north and south, The nearest populations to the south occur in south-central Georgia, a disjunction of approximately 440 miles!  From there, Lophiola's known distribution (based on USDA PLANTS database) skips over another approximately 140 miles before re-appearing in the panhandle of Florida (where it seems to be most widespread), and adjacent Alabama and southern Mississippi. Interestingly, another widely disjunct population has been reported in western Louisiana. To the north, the species re-appears in New Jersey and a few points beyond including Nova Scotia!  These northern populations may be the most unexpected.  To quote G.E. Nichols (Rhodora 1919), "Lophiola aurea in Nova Scotia. Surely there must be a mistake".  But no mistake...it occurs there along with a number of other disjunct populations of typically southeastern US coastal plain species.

Lophiola aurea population in Brunswick Co, NC
(dark shadow on left is dense woods)

Back in North Carolina, the small population shown here (left) was holding on at the very edge of a power-line clearing. Maintenance activities and off-road vehicles had torn up much of the adjacent ground while the surrounding woods appeared to be too dense and overgrown (unburned) to support the plant.

Last summer I observed Lophiola in all its glory in an open pine savanna in north Florida. It's almost embarrassing how much time I spent watching small bees visit the tiny (~ 10mm wide) flowers. Since I did, I'll include a few images here:
Lophiola aurea pollinator, south of Tallahassee Florida
July 5, 2014

I'd be interested to know what species this little bee is, and whether or not it occurs throughout Lophiola's highly fragmented range.

Sunday, July 12, 2015

Oh Dread! Another Naturalized Exotic Plant?

Driving down the highway along the Northeast Cape Fear River near Wilmington recently, I caught a glimpse of the plants shown above.  The 5-6' tall plants with bright yellow flowers were unfamiliar so I risked life and limb and pulled a U-turn on the heavily traveled road to take a closer look.

Ludwigia bonariensis, near Eagle Island, NC
July 7, 2014

The plants were incredibly attractive and intriguing.  I concluded they were most likely Ludwigia bonariensis.  I was excited by the comment in the Manual of Vascular Flora of the Carolinas which listed it as "very local; Brunswick and New Hanover cos." --- this thing was rare!

But then I got confused!

A later check of Godfrey & Wooten (Aquatic & Wetland Plants of the Southeastern United States) listed it as  "Local, s.e. N.C.; Fla." but added, "native of Trop. Am." --- this thing was exotic!

Weakley's Flora stated it is "apparently native of tropical America" and suggested it may have been introduced on ship's ballast, while noting our plants appear to differ somewhat from specimens elsewhere.

NatureServe considers it exotic in NC, SC, and AL, but lists it as "critically imperiled" in Arkansas. Also of interest is the common name used by NatureServe; "Carolina Seedbox" - an odd name for something from the tropics.

USDA Plants lists it as native in NC, SC, AL, and FL and doesn't record it all from Arkansas.

Both USDA Plants and NatureServe omit the record that showed up in an artificially created wetland in VA around 10 years ago....

My head is humming and it won't go - in case you don't know.....

Ludwigia bonariensis sepals and capsules, just west of Wilmington, NC