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RHODORA, Vol. 98, No. 896, 365-368, 1996 pp. HEUCHERA MICRANTHA MACROPETALA VAR. NEW (SAXIFRAGACEAE), A VARIETY B. G. Shipes Department Hampton of Biological Sciences, University, VA Hampton, 23668 Wells E. F. Department The George Washington of Biological Sciences, University, DC Washington, 20052 ABSTRACT. This ncwly described variety of Heuchera micrantha char- is acterized by the presence of widely ovate petals, a cyathiform calyx, and in general, a taller inflorescence than the other varieties of//, micrantha. Clearly from different the other varieties of H. micrantha in the shape of the flower, in the greater width of the petal, and in having fewer flowers per lateral branch of the inflorescence, appears to be distinct at the varietal level. The it cyathiform calyx not found in any other H. micrantha variety. The exserted is stigmas and stamens, the size of the flower, the leaf shape, and indumentum common are characters held in with the other varieties of//, micrantha, which place this taxon within our circumscription of the species. Key Words: Heuchera micrantha macropetala, Micranthae, var. var. nov., cyathiform calyx In their monograph on Heuchera, Rosendahl, Butters, and La- kela (1936) treated H. micrantha as a polymorphic species with From and two five varieties forms. locations in the Siskiyou (Or- egon and and Klamath Mountains California) (California) they reported the existence of a number of specimens which no fit and which varietal description they identified as transitional forms. Since the publication of their work, specimens from the same populations within these locations collected in different years have been H. micrantha micrantha, H. identified as var. micrantha H, micrantha erubescens, and var. pacifica, var. //. Some pilosissima. of these populations share a stable set of mor- phological characteristics and, in a recent revision oi Micranthae and Heuchera Pilosissimae of in the Saxifragaceae (Shipes 1988), new a variety of Heuchera micrantha has been recognized in this region of northern California and southern Oregon. For clarity new and bibliographic convenience, the variety validated, de- is and explained scribed, briefly here. 365 366 Rhodora 98 [Vol. Heuchera micrantha Dougl. ex Lindl. niacropetala Shipes var. & Wells, var. nov. Type: Oregon, Curry Co., Big Craggy, 12 Jun 1933, Leach (holotype: ore!; isotype: osu!) L. s.n. Calycibus cyathiformibus usque ad non profunde turbinatis; pe- cum talis late ovatis, vix unguiculatis, tribus typis venationis: (1) una vena principalis cum 2-4 venis una vena mi- lateralibus; (2) dia; venatio imperfecta suprabasalaris acrodroma (3) (3-5). Leaf blade semi-orbicular pentagonal, forms to at least 3 leaf on each plant: blade semi-orbicular with 7 very shallow lobes, (1) each lobe with lateral lobes; blade pentagonal, the length (2) 5-7 equal to the width, with lobes, each lobe with lateral lobes; blade pentagonal, the length greater than the width, with 7 (3) cm cm lobes, blade 3.5-7.0 from base apex, 2.4-7.0 wide, to main somewhat lobes spreading with crenate sublobes. In three all forms the lobe apices and teeth are cuspidate to acute apiculate mm (1.0 vein extension); leaf bases cordate; margins sparingly upper ciliate; leaf surface glabrous to sparsely strigose; lower leaf cm surface sparsely villous to strigose on veins; petioles 4.2-15.0 sometimes long, puberulent, sparsely villous. Inflorescences cm 6.0-57.0 somewhat cm 2.3-11.0 broad, axes tall, lax, lateral with even puberulence, sometimes short, sparingly villous; pe- duncle bracts scarious, lanceolate to linear, occasionally large, similar to basal leaves in shape but never as large; bracts sub- tending branches herbaceous, margins floral divided, divisions with aristate tips. Calyces cyathiform (shaped like a small, shal- mm low bowl) to shallowly turbinate, 1.0-3.4 long and 1.3-3.6 mm mm wide hypanthia at anthesis; free long; sepal lobes l.I mm usually white with green or red rounded, 0.5-1.5 tips, long. Petals white, widely ovate, barely clawed, with three types of 2-4 venation; one main vein and almost parallel lateral veins; (1) 3-5 single mid-vein; secondary veins branching supra- (2) (3) mm mm from one main basally vein; 1.5-3.5 long, 0.4-1.4 wide with puberulent patches in the upper 1/3 of the blade; margins mm Stamens beyond entire. at anthesis exserted 1.0-3.2 calyx. mm Styles at anthesis exserted 0.1-2.5 from calyx, length of style and portion of ovary above hypanthium the the anthesis 1.2- at mm mm. 3.9 Capsules exserted, 2.5-5.0 long excluding persistent mm mm seeds dark brown, styles; echinate, 0.7 long, 0.4 wide. PHENOLOGY. Flowering from middle of April through middle of June. — Shipes and Wells Heuchera 367 1996] Mixed HABITAT. evergreen forest on either limestone or serpen- tine base, in the Klamath Mountains of California and the Sis- kiyou Mountains of California and Oregon. Latitude 40-43°N. This newly described variety characterized by the presence is of widely ovate petals, a cyathiform calyx, and in general, a taller Heuchera inflorescence than the other varieties of micrantha. Based on and inflorescence characters, appears to floral, fruit, it from be distinct at the varietal level. is clearly distinct the other It varieties of H. micrantha in the shape of the flower, in the greater petal width, and in having fewer flowers per lateral branch of the The cyathiform calyx not found any other H. inflorescence. in is micrantha variety. However, the exserted stigmas and stamens, indumentum and the size of the flower, the leaf shape, are char- common acters held in with the other varieties of H. micrantha, which place taxon within our circumscription of the species. this NW Representative specimens. Oregon: Curry Co., Bald Mt. Creek, ex- posure, McGribble Forest Service Camp, T33S, R24W, Sect. 20, Detling 5880 W Rogue River Canyon, rock ledges along Rogue River of Brushy (ore); Baker 3832 Camp, Leach 1889 Big Crag- Bar, (jeps, uc); Squirrel (ore, osc); 6/12/33, Leach (ORE, osu); Forest Service Rd. #333 (Powers-Agness gy, s.n. N Rd.), 3 mi of the jet with #330, Agness vicinity, Crosby 1224 (ore); W Siskiyou National Forest, 16-18 mi of jcl of Hwy. 199 with Forest Service Rd. 3807 on 3807 (Rd. to Kalmiopsis Wilderness), Denton 2350 (osc, uw); Josephine Co., Mouse Creek on Rogue River, 2.3 mi upstream from bridge mouth of Graves Creek, Crosby 1154 (oh, ore, osc); Graves Creek Rd., at mi E of of Graves Creek with Rogue River, T33S; R7W, Sect. 31, Crosby jet 1 NW 1153 (osc); Siskiyou National Forest, 20-23 mi of Selma on the Illinois N River Rd. or 8-11 mi of with 374 on Forest Service Rd. 3504, jet Rt. Denton 2475 (uw); Lane Co., Ollalie Trail in Willamette National Forest, T16S, R5E, Ireland 1117 (ore); California: Humboldt Co., Horse Ml., T6N, R4E, Sect. 34, Klipfel 676, 680 (hsc); Little Horse Linto Creek below Grizzly E Camp, Tracy 18976 (uc); Willow Creek, fork, T6N, R4E, Sect. 15, 34 mi US from 101 along State Rt. 299, Reed 66 (hsc); Shasta Co., Redding, 25 E mi E, Hitchcock 6481 (pom, uw); Siskiyou Co., State Rt. 299, 0.2 mi of jet with Hennessey Rd., 4/30/72, Sawyer, s.n. (hsc); rd. between Forks of & Salmon Somes Smith 8695 Kangaroo Mt. above Toehead Lake, Bar, (hsc); & T18N, R12W, SmitK Sawyer O'Mear 5675 Salmon Sect. 16, (hsc); River, E S fork of road 4 mi of Cecilville, Irwin 44501 (hsc); Salmon River, 10 mi & SE TION, R6E, Sect. 30, Miller 10108 (hsc, rsa); Slater Butte Indian Creek, Klamath National Forest, Detling 6098 (ore); Trinity Co., Burnt W Ranch, 8 mi on Underwood Mt. Rd., Spellefiberg 454 (hsc); Canyon Creek McKay above Camp, 65 Gray above Ferlatte (hsc, rsa); Falls, trails the Humboldt T6N, R7W, 8098 Trinity River, Meridian, Sect. 34, Smith (hsc, New Gray River T6N, R6E, Limdquist 58 rsa); Falls, Trail, Sect. 35, (hsc); 368 Rhodora 98 [Vol. Gray Falls Campground above the Trinity River, DeTomaso 924 (hsc); Hobo NW Camp N Gulch and mi vicinity (18 of Weavervillc, along fork of trail at the washout below Struce Cabin), Carter 546 (cas); Ironside Mt. Quad. T6N, R6E, Sawyer 2499 Sawyer 2601 Whitens Sect. 35, (hsc), (hsc); Bar, & above Sawyer Stale Rt. 299, Cole (nsc). LITERATURE CITED A and RosFNDAHi., C. O., K. Butters, O. Lakela. 1936. monograph on F. genus Heuchera. Minnesota the Studies in Plant Sciences 1-180. 2; A Shiphs, B. G. 1988. systematic survey of subsections Micranthae and Pilosissimae section Heuchera in the genus Heuchera (Saxifragaceae). Ph.D. dissertation, The George Washington University, Washington, DC.