Coreopsis bakeri E. Schill., 2015

Schilling, Edward E., Johnson, Ann F. & Iacona, Gwenllian D., 2015, Coreopsis bakeri (Asteraceae; Coreopsideae), a new species from Florida, USA, Phytotaxa 231 (2), pp. 175-181 : 179

Coreopsis bakeri E. Schill. , sp. nov.

Type:— USA. Florida: Jackson County, “Brooks 1” limestone glade. 30.81273° N, – 85.25771° W ; 48 m elev., 18 April 2013, A. F. Johnson with W. Baker 10623 (holotype: FSU!; isotype: TENN!) .

Diagnosis: —Resembling Coreopsis lanceolata , but differing by having narrower, infolded, unlobed, and completely glabrous leaf blade surfaces.

Laxly erect perennial 20–35 cm tall. Stems clustered, arising from a caudex 1–3.5 cm long, leafy below but elongate and naked above. Stems and peduncles ridged, glabrate, shortly papillose, 1.5–2 mm wide at base. Flowering stems with 1–2 pairs of leaves below the peduncles. Leaves linear to narrowly oblanceolate, usually unlobed or with 1–2 small lateral lobes, 11–29+ × 0.3–1.4 cm and 15–30 × as long as wide, infolded, stiff, surfaces glabrous, margins with a few minute appressed cilia. Heads usually solitary, peduncles 15–30 cm long, heads ca 4–5 cm wide between tips of opposite rays. Outer phyllaries narrowly ovate and attenuate, 6.5–8 × 2.5–3 mm; inner phyllaries ovate, acute, 9–11 × 3.5–4 mm. Ray flowers yellow, ligules 2–2.5 cm long, shallowly 4–5 toothed at apex. Disk flowers yellow, 5-lobed, 3.5–5 mm long. Chaffy bracts flat, long-attenuate, 7–8 mm long. Cypsela bodies blackish, papillose, 3–3.4 mm long, 1.4–1.8 mm wide; awns 0.5–0.9 mm long; wings brownish, 0.7–1.4 mm wide, entire. Chromosome number: unknown. Flowering March–April; fruiting June. Fig. 1 , 2 .

Additional specimens examined (paratypes):— USA, Florida, Jackson Co (in vicinity of town of Marianna): “Williams 2” limestone glade, 30.819035° N ; – 85.282282° W, 28 April 2009, A. F. Johnson 10353a with Wilson Baker ( FSU) ; “ Williams 3” limestone glade, 30.81791° N, – 85.279409° W, 28 April 2009, A. F. Johnson s.n. with W. Baker ( FSU) ; “west of SR 73 ” limestone glade, 30.779349° N, – 85.275165° W, 28 April 2009, A. F. Johnson 10360a with W. Baker ( FSU) ; “old car” limestone glade, 30.823771° N, – 85.258544° W, 25 June 2008, A. F. Johnson 10239a with W. Baker ( FSU) ; “ Brooks 1” limestone glade, 30.812453° N, – 85.257063° W, 25 March 2006, L. C. Anderson 21598 ( FSU) .

Etymology:—The species is named for Florida naturalist, Wilson Baker, who, with Steve Leonard, discovered many of the Florida upland glades and some of their associated rare species in the 1980s and has worked with the owners to allow botanists access to them ever since.

Distribution and ecology:— USA, Florida, apparently endemic to Jackson County ( Fig. 3 ). Coreopsis bakeri is consistently present on all nine known Jackson County glades, often in those portions with the thinnest soil or where bare rock is exposed ( Fig. 2 ), in association with Sporobolus vaginiiflorus and Rhynchospora divergens . It was also found on five possible former glades—areas that had been altered by soil disturbance followed by the invasion of centipede grass ( Eremochloa ophiuroides ), a turf-forming lawn grass with which most other glades species cannot compete. It has not been found in other habitats in Jackson County, or on glades in Gadsden County (where C. lanceolata does occur; Johnson et al. 2013). Glades in the two counties are about 40 km apart, separated by the floodplain of the Apalachicola River, and occur on different geological substrates.

The Florida upland glade habitat of Coreopsis bakeri is largely in private ownership and is highly vulnerable to alteration. Only one of the nine known Jackson County glades has conservation status—a small glade on the property of Florida Caverns State Park. Since the nine glades were identified, two have been destroyed by mining and one damaged by plowing for a food plot. The remaining glades would probably best be protected by either conservation easement or purchase and addition to the state park. In view of its limited habitat and distribution, C. bakeri would likely warrant a G1S1 ranking by NatureServe, and an “endangered” ranking by the US Fish and Wildlife Service. In addition to habitat loss, another threat to the continued existence of C. bakeri may be posed by the presence of its congener, C. lanceolata , either through direct competition or by genetic assimilation through hybridization. Although C. lanceolata is now widespread in the eastern U.S., its original distribution has been suggested to be the central and southwestern U.S. ( Cronquist 1980), making its nativity in Florida unclear. Coreopsis lanceolata has been documented to be a problem invasive in Japan ( Saito & Okubo 2012), demonstrating its ability to occupy new habitats. Furthermore, our results that document successful crossing between C. bakeri and C. lanceolata coupled with those of Smith (1976), who reported relatively high fertility in some crosses between C. lanceolata and other members of C. sect. Coreopsis , suggests the potential for gene flow between the two species. Thus, further studies and monitoring of populations of C. lanceolata in the near vicinity of those of C. bakeri are needed.

Figures

FIGURE 1. A–D. Coreopsis bakeri. A. Habit. B. Pale, Disk flower. C. Cypsela (achene). D. Leaf.

FIGURE 2. A–B. Coreopsis bakeri. A. Habitat, with blooming plants. B. Plants in bloom, showing substrate with exposed bare rock. Photographs taken by A. Johnson.

FIGURE 3. Map showing locations of the nine known populations of Coreopsis bakeri in Jackson Co., northern Florida, USA.