PlantaeSaxifragalesHamamelidaceaeHaynesJake E.PhillipsWhitney D.KringsAlexanderLynchNathan P.RanneyThomas G.Revision of Fothergilla (Hamamelidaceae), including resurrection of F. parvifolia and a new species, F. milleriPhytoKeys1732020144578010.3897/phytokeys.144.49589988E10E7-FD07-532B-8B40-80EC41C51904 Fothergilla parvifolia Kearney in Small, Fl. S.E. U.S. 509, 1331. 1903Type.

Georgia. Wayne Co., Jesup, dry soil, 4 June 1893 (FR), Kearney s.n. (Holotype: NY!; isotype: F [online!]). Figs 1B, 3B, 8, 9.

Description.

Shrub, rhizomatous, erect, to 1 m tall, clump-forming, multi-stemmed, branching. Leaves: stipules ovate to lanceolate, 3.5–6.0 × 8.0–13.0 mm, curved downward; petioles 4.4–17.8 mm long, usually nearly as long to longer than the IL, brown-yellow pubescent; blades drooping, green, mostly ovate, 3.2–12.1 × 3.0–6.2 cm, pinnately 8–10-veined, bases cordate, margins crenate to serrate from middle, apices acute, adaxial and abaxial surfaces not glaucous, stellate-pubescent, sometimes sparsely so, IW:IL > or = 0.62 (x̄ = 0.96). Inflorescences appearing before leaves, spikes on short peduncles or sessile. Flowers: stamens 15–20 per flower, filaments 6.6–9.3 mm long. Capsules 7.5–10.0 × 5.0 –7.6 mm. Seeds usually completely brown to red-brown, ovoid, apex obtuse, 4.5–6.2 × 2.4–3.2 mm, apices obtuse to acute. Genome size and ploidy 1.73–1.82 pg, diploid (2n = 2x = 24).

Phenology.

Flowering Mar–May; fruiting May–Sep.

Distribution and habitat.

This species range is restricted to Georgia, South Carolina, and Alabama (Fig. 5). Because there are few herbarium records for this species, little is known about its exact distribution and environmental restrictions. According to the few notes available on herbarium specimens, it occurs in seepages and margins of bogs, bay swamps, and watercourses.

Conservation.

The conservation status of this species needs to be assessed. It is presently known from only eight counties, and would appear to have an imperilment status at least as severe as that of F. major. Consequently, only skeletal collections data are provided below.

Additional specimens seen

[(V) = vegetative only, (FL) = in flower, (FR) = in fruit].

Alabama. Montgomery: 12 Sep 1899 (FR), Harbison 1033 (NCUm).

Georgia. Augusta-Richmond: 2 Apr 1898 (FL), Cuthbert s.n. (FLAS). Brantley: 23 Aug 1947 (V), Thorne & Norris 6284 (GEO [online!]). Emanuel: 2011-170, 2 Jul 2012 (V), Lynch 19 (NCSCm); 2011-170, 15 Mar 2013 (FL), Lynch 33 (NCSC); 2011-170, 14 Jun 2014 (FR), Phillips 60 (NCSC). Long: 2011-171, 2 Jul 2012 (V), Lynch 20 (NCSCm); 2011-171, 14 Mar 2013 (FL), Lynch 32 (NCSC); 2011-171, 13 Jun 2014 (FR), Phillips 61 (NCSC); Tattnall: 2011-168, 19 Mar 2013 (FL), Lynch 35 (NCSC); 2011-168, 2 Jul 2012 (V), Lynch 18 (NCSCm). Wayne: 31 Aug 1904 (V), Biltmore Herbarium 14940 (NY [online!]).

South Carolina. Aiken: 2012-084, 15 Apr 2014 (FL), Lynch 40 (NCSC); 2012-084, 13 Jun 2014 (V), Phillips 56 (NCSCm). Lexington: 13 Sept 1988 (V), Pittman 9139817 (BRITm); 27 May 1957 (FR), Radford 23378 (NCUm).

10.3897/phytokeys.144.49589.figure8771A3A11-F120-54F5-951A-2655920E0190

Fothergilla parvifoliaa plant form and leaf orientation b adaxial leaf surface c abaxial leaf surface d inflorescence e young infructescence f stem g twig h capsule, and i seeds. Photos by J. Haynes of plants at the Mountain Horticultural Crops Research and Extension Center, Mills River.

https://binary.pensoft.net/fig/39081210.3897/phytokeys.144.49589.figure91B2327B1-D75C-57D1-8340-1DDB334AF520

Distribution of Fothergilla in the southeastern United States. Circle = F. major (6x); triangle = F. gardenii (4x); star = F. milleri (2x); plus sign = F. parvifolia (2x). Physiographic provinces follow Fenneman and Johnson (1946), shape files courtesy of usgs.gov. AP = Appalachian Plateau; BR = Blue Ridge; CP = Coastal Plain; ILP = Interior Low Plateau; OP = Ozark Plateau; Pd = Piedmont; VR = Valley and Ridge. Map generated by A. Krings in QGIS (QGIS Development Team 2019).

https://binary.pensoft.net/fig/39081310.3897/phytokeys.144.49589.figure10BDC3B8B-5E0F-5D27-9958-E0786D502544

Leaf shape and base variation in Fothergilla: Ai–AiiFothergilla major (V-cordate/V-rounded, i.e. with distinct cuneate portion at extreme blade base that broadens out laterally to cordate [Ai.] or rounded [Aii.]) Bi–BiiFothergilla parvifolia (note the neatly cordate bases without well-defined cuneate portions at extreme blade base) Ci–CiiFothergilla milleri (bases rounded). Fothergilla gardenii not shown as bases are variably rounded, cuneate, or cordate. IL = the length of the midvein interval between the junction of the midvein and lowermost secondary vein and the junction of the midvein and the next-most distal secondary vein on the same side of the leaf; IW = the width, at the widest point, of the intervening leaf surface between the lowermost secondary vein and the leaf margin. Illustrations by A. Krings based on Lynch 29 (Ai.), Lynch 21 (Aii.), Phillips 56 (Bi.), Lynch 18 (Bii.), Lynch 68 (Ci.), and Lynch 69 (Cii.).

https://binary.pensoft.net/fig/39080510.3897/phytokeys.144.49589.figure329856596-3D8E-546D-9821-666080EA0A94

The two leaf orientations found in the diploid lineages of FothergillaA erect leaves of F. milleri (aggregate profile 2) B drooping leaves of F. parvifolia (aggregate profile 1). Photos by J. Haynes of plants at the Mountain Horticultural Crops Research and Extension Center, Mills River.

https://binary.pensoft.net/fig/39080710.3897/phytokeys.144.49589.figure5FEF05CC6-F246-57B9-9421-919DFD3C51E1

Fothergilla gardeniia plant form and leaf orientation b adaxial leaf surface c abaxial leaf surface d inflorescence e young infructescence f stem g twig h capsule, and i seeds. Photos by J. Haynes of plants at the Mountain Horticultural Crops Research and Extension Center, Mills River.

https://binary.pensoft.net/fig/390809FennemanNMJohnsonDW (1946) Physiographic divisions of the conterminous U.S. U.S. Geological Survey, Reston.QGIS Development Team (2019) QGIS Geographic Information System. Open Source Geospatial Foundation project. http://qgis.osgeo.org