State Records (continued)

Solanum pumilum Dunal

Thomas Nuttall (1834) described Solanum hirsutum Nutt., from material collected by Samuel Boykin (Boykin s.n. PH) from the vicinity of Milledgeville, Georgia. Boykin collected the Solanum again in 1837 (specimen at NY, cited in D'Arcy 1974), from near Columbus, Georgia.

Two decades previous to Nuttall's publication, Michel Felix Dunal (1813) had described a different Solanum hirsutum (and Roxburgh yet another, soon thereafter). Nuttall's name was therefore (doubly!) a later homonym and must be rejected. Dunal (1852) rectified the situation by renaming Boykin's plant S. pumilum Dunal.

Asa Gray (1878) reduced the taxon to a variety of Solanum carolinense L., resurrecting Nuttall's epithet at varietal rank, a disposition followed by William D'Arcy (1974). As this was a taxon known only from three old specimens, the conservative treatments of Gray and D'Arcy were entirely defensible.

As of 1992, the two collections by Boykin, three sheets more than a century and a half old, were still the only known material of this taxon, and the plant was regarded as probably extinct (Shortia Torr. & Gray, after all, was lost to science for less than 90 years). On April 26, 1993 we discovered small populations of this Solanum (Figure 14) on two outcrops of Ketona Dolomite near the Little Cahaba River (A. and S. 7557, NY; A. and S. 7563, US). Subsequent exploration revealed that this taxon occurs about the margins of many of these glades and on at least one small glade of a different dolomitic formation (A. and S. 7651, VDB).

On May 1, 1994 we visited some amphibolite outcrops approximately 57 km to the southeast of the Ketona Glades. West of the Coosa River, in Chilton County, Alabama, we found (A. and S. 8239, MO, NY, VDB) one moderate-sized population of Solanum pumilum, and east of the river, in Coosa County, one rather small population (A. and S. 8241, UNA).

Other populations exist on Bibb County glades, but we saw many of these only in vegetative condition and they were not vouchered. After observing about 20 populations of this taxon, we have concluded that, though clearly related to Solanum carolinense, it should be recognized at the species level. Michael Nee, of the New York Botanical Garden, to whom we sent material of S. pumilum in 1998, concurred, writing (pers. comm. 1998), "its similarity to S. hieronymii and other spp. from Bolivia/Paraguay is striking, but obviously a good, distinct species."

There are multiple characters by which Solanum pumilum can be distinguished from S. carolinense, whereas the two varieties of S. carolinense, var. carolinense and var. floridanum (Shuttlw. ex Dunal) Chapman, reportedly can be distinguished only by leaf shape and, moreover, intergrade freely (D'Arcy 1974). Solanum pumilum differs from S. carolinense by (1) its smaller stature, less than 2 dm, vs. usually 3-10 dm; (2) stems without spines; (3) leaves rounded to obtuse at the apex, entire to shallowly sinuate, their prickles absent or few, weaker, and confined to the midvein [vs. mid- and late-season leaves acute, coarsely dentate (or deeply lobed in var. floridanum), prominently spiny on midvein and often also on secondary veins]; (4) corollas always pure white (usually lavender in S. carolinense, although white morphs—f. albiflorum O. Kuntze—are occasional); and (5) flowers sweetly fragrant, vs. odorless (pers. obs. of Allison over southeastern states from Arkansas to North Carolina) in S. carolinense.

Solanum carolinense is a common, native weed in the southern states (and beyond) and is found on a few Ketona Glades where there has been some disturbance, e.g. from road construction or lumbering activities. These plants are usually stunted by the extreme conditions prevailing on the glades, and thus resemble S. pumilum in stature. In all other respects, most noticeably in having cauline prickles and upper leaves coarsely dentate, they are easily recognizable as S. carolinense.

Spiranthes lucida (H. H. Eat.) Ames

Like Rhynchospora capillacea, Spiranthes lucida is very rare as far south as Tennessee, its previous southern limit, and is thus far known in Alabama from a (different) single rocky place on the right bank of the Little Cahaba River. Allison discovered this, the latest of the state records, while canoeing the Little Cahaba River with Jim Affolter and David Handlay, on April 29, 1994. We could find only ten or so individuals, and the population was vouchered by photographic slides and prints the authors took the next day, A. and S. 8224-p (AUA, JSU, UNA, VDB). We revisited  the site a month later, hoping to collect seed, but, perhaps due to a very dry May, the infructescences had senesced, apparently without perfecting any seed.

The single locality known is a ledge of dolomite just above the river, where a glade extends down to the water's edge and where Spiranthes lucida is associated with Rhynchospora colorata and R. thornei. It is probably slightly inundated at times in winter and after heavy rains. Like Baptisia australis var. australis and Rhynchospora capillacea, Spiranthes lucida is considered a peripheral element of the Ketona Glade flora.