Sedum marmorense Otting & R. E. Brainerd, 2018

Zika, Peter F., Wilson, Barbara L., Brainerd, Richard E., Otting, Nick, Darington, Steven, Knaus, Brian J. & Nelson, Julie Kierstead, 2018, A review of Sedum section Gormania (Crassulaceae) in western North America, Phytotaxa 368 (1), pp. 448-450 : 448-450

7. Sedum marmorense Otting & R. E. Brainerd , sp. nov. Figs. 32 G–L , 33

Species Sedum oblanceolatum proxima sed differt foliis basalibus rosulatis obovatis, a Sedum oregonensis rosulis densissimis et inflorescentiis granularibus ceraceisque.

Type: — UNITED STATES. California: Siskiyou Co., Klamath Mountains, Marble Mountain Wilderness Area , Upper Wright Lake , 2295 m, 12 July 2013, R. E . Brainerd 2180 & N . Otting (holotype, OSC; isotypes, GH, NY, RSA, UC, WTU) .

Rhizomes and stolons 1–6.5 cm long, 1.2–3.5 mm in diameter. Rosettes not numerous, 17–36 mm diameter, densely arranged, generally without visible internodes in exposed situations. Rosette leaves green or glaucous, but not granular waxy, often with red margins, aging red then orange, strongly flattened dorsiventrally, obovate, oblanceolate, or lanceolate, 6–24 × 3–11 mm, length to width ratio 1.3–2.8; base cuneate; tip retuse to rounded. Stem leaves ascending to slightly spreading, slightly to strongly glaucous, but not granular waxy, green, pink, or red; ovate, obovate, oblong, or occasionally lanceolate, 7–10 × 2–6 mm, length to width ratio 1.3–3.6, flattened, base truncate; tip acute to rounded or shallowly retuse. Fertile stems green, pink, or red, 4.4–15 cm, nodding in bud, erect in flower and fruit. Inflorescences (0.5–)1.4–6.0 × (0.5–) 1.8–4.5 cm, length to width ratio 0.7–1.8, often globose to subglobose, occasionally more elongated, usually densely flowered, paniculate cymes. Proximal branches 3–7, ascending, (0.3–) 1–2.8 cm, solitary at nodes; all branches with granular waxy flakes early in season. Inflorescence bracts resembling stem leaves but smaller, 4–9 × 1–3 mm, length to width ratio 2–4; bases truncate, tips (acute to) obtuse or rounded. Flowers 6–42 per inflorescence. Calyx green, with granular waxy flakes early in season, 3.5–5.2 × 2.7–4.3 mm; 32–69% as long as perianth; sepals fused basally for 0.5–1.5 mm, lobes 2.4–4.7 mm, acute, less often obtuse, the very tip rounded. Petals 5, 5.3–7.5 mm, 1.4–2.8 mm wide at midlength, fused at base for 0.9–2.5 mm, ascending at an angle of 5–20° from the floral axis at anthesis, white, cream, or light yellow, aging pale yellow or pink; midvein green, cream, or pale yellow, often aging pink; apiculate, the mucro 0.1–0.3 mm. Stamens 10, shorter than the petals; filaments cream or yellow, often almost transparent, aging red; anthers 0.8–1 × 0.3–0.6 mm (when dried), yellow, aging red-orange or reddishbrown, papillose at 20×. Nectaries shallowly crescent-shaped, sunken in middle, yellow, 0.5–0.7 mm, 0.1 mm high. Ovaries 3.8–8.5 mm, erect, fused for 0.7–1.5 mm, maturing into 5 dark red-brown, erect follicles. Follicles 6.6–7.2 mm, with erect to slightly curved style remnant forming a narrow beak approximately 2 mm; bases fused for 0.8–1.5 mm. Seeds 12–31 per follicle, brown, narrowly elliptic, shiny, longitudinally striate, 0.7–1 × 0.15–0.3 mm (including stipe), stipe 0.05–0.1 mm.

Paratypes: — UNITED STATES. CALIFORNIA. Siskiyou County: Marble Mountains , 8 August 1939, Howell 15141 ( CAS, POM) ; Marble Mountains , NE of Red Mountain, 2345 m, 12 July 2013, Brainerd 2185 & Otting ( OSC) ; Tom Martin Peak , 2023 m, 11 July 2014, Otting 3837 ( CAS, MO) ; Lake Mountain , 2080 m, 6 July 2014 m, Otting 3831 & Brainerd ( OSC) ; Lake Mountain , 2034 m, 6 July 2014, Otting 3832 & Brainerd ( CAS, JEPS, WTU) .

Distribution and ecology: —Endemic to a narrow zone 19 km long in the Marble Mountains, in the Klamath Ranges of Siskiyou Co., California ( Fig. 22 ). We uncovered three extant populations, at elevations of 2023–2345 m, on broad flat stony crests to moderate slopes. Aspects varied from south to west to north. Flowering was observed in July, but this was following winters with very low snow cover. The sites were dry sunny cracks and crevices on rocky ridgelines, in low ledges or massive outcrops, as well as in soil pockets on a talus slope among boulders. The underlying bedrock was metasedimentary, metavolcanic, and ultramafic, according to geologists on the Klamath National Forest (Juan de la Fuente and Derek Beal, pers. comm.). Some common associates included: Achillea millefolium L., Arctostaphylos sp. , Calamagrostis sp. , Eriogonum umbellatum Torr. , Festuca roemeri (Pavlick) E.B. Alexeev , Heuchera sp. , Holodiscus discolor (Pursh) Maxim. , Lomatium macrocarpum (Hook. & Arn.) J.M. Coult. & Rose , Myriopteris gracillima (D.C. Eaton) J. Sm. , Penstemon deustus Douglas ex Lindl. , Polystichum sp. , and Pseudoroegneria spicata (Pursh) Á. Löve.

Etymology: — Sedum marmorense , or Marble Mountains stonecrop, was named for the Marble Mountains and for the marble substrate on which it sometimes grows.

Notes: — Sedum marmorense ( Fig. 32G–L ) resembled S. oregonense , but the former has waxy granules on the calyces and inflorescence branches, and was a more delicate plant with looser rosettes. Sedum marmorense differed from S. albomarginatum and S. oblanceolatum in its relatively wide rosette and stem leaves ( Fig. 33E–F ), and in the relative difference in leaf shape and size between the rosettes and stems ( Fig. 33H ). Sedum oblanceolatum and S. albomarginatum had oblanceolate foliage that was quite similar on the stems and the rosettes (e.g., Fig. 21B ). As with some farinose species of North American primrose ( Primula Linnaeus 1753: 142 ), the waxy particles can melt away from specimens dried with heat, complicating identification.

Figures

FIGURE 21. Sedum albomarginatum. A. Habit. B. Two flowering stems, the oblanceolate rosette leaves and stem leaves were similar in length and outline, the stem leaves were consistently elongated proximally and distally. C. Rosette leaves, fresh ones waxy, older weathered ones green. D. Stem leaves, showing truncated base. E–G. Dense white granular wax coating on fresh leaves, bracts and sepals, easily rubbed off on fingers. F. Flower and bud, showing erect pale yellow petals, white granular wax coating was dense on fresh sepals and bracts, sparse on corolla. G. Densely white granular waxy rosette leaves. A–D, G. Plumas Co., California (Zika 25865). E–F. Butte Co., California (Zika 25867).

FIGURE 22. Distribution of Sedum albomarginatum, S. citrinum, S. marmorense, S. moranii, S. oblanceolatum, and S. patens, based on verified herbarium specimens.

FIGURE 32. A–F. Sedum rubiginosum. A. Habit, showing dense rosettes, overlapping stem leaves, and cylindrical densely-flowered inflorescence. B. Flower, side view, showing spreading petals. C. Flower, top view, showing gradual taper to narrow petal tips.A–D. Zika 25522 & J.K. Nelson. E. Rosette leaf. F. Stem leaf. E–F. Zika 26234. G–L. Sedum marmorense. G. Habit, showing stolons and dense rosettes. H. Rosette leaf. I. Stem leaf. G–I, K–L. (Brainerd 2180 & Otting). J. Flower, side view, showing granular wax on sepals and ascending petals (Otting 3837). K. Flower, top view, showing acute broad petal tips. L. Petal apex, showing projecting subapical mucro on right, and hooded petal tip on left.

FIGURE 33. Sedum marmorense. A–D. Habitat, Siskiyou Co., California.A, D. Brainerd 2180 & Otting. B: Otting 3832 & Brainerd. C: Brainerd 2185 & Otting. E. Two fertile shoots, yellow flowered. F. Two fertile shoots, erect and just about to flower, white flower buds. G. Dense rosettes, new growth slightly glaucous and whitened, but not granular waxy. H. Oblanceolate stem leaves on left, rosette leaves on right. I. Sheltered sterile shoot with loosely arranged leaves. J. Young nodding inflorescences, flower color not yet apparent. K. Obovate stem leaves, bases truncate. L. Flower buds, granular white wax on sepals, white-flowered form. M. Flowers, side view, ascending white petals, sepals not showing granular white wax, slightly more weathered than L. N. Flower, side view, ascending pale yellow petals, granular white wax on sepals of flower buds. O. Flower, top view, ascending pale yellow petals, granular white wax on sepals. E–O. Brainerd 2180 & Otting.