Sedum rubiginosum Zika & B. L. Wilson, 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

14. Sedum rubiginosum Zika & B. L. Wilson , sp. nov. Figs. 1D–E , 4C–D , 11D , 15E , 24C–D , 32A–F , 43

Differt haec species a Sedum kiersteadiae rosulis foliorum densis, floribus numerosioribus, sine vel reduci mucrone abaxiali subterminali, necnon foliis caulinis numerosis imbricatisque.

TYPE: — UNITED STATES. California: Tehama County, SE of Tedoc Mountain , 1490 m elevation, 5 July 2011 , P. F. Zika 25522 & J. K. Nelson (holotype, WTU; isotypes, CAS, OSC).

Rhizomes and stolons to 30 cm long, 2–11 mm diameter; sterile leafy shoots not numerous, rosettes 14–120 mm diameter. Rosette leaves often densely arranged without visible internodes, glaucous, at least when young, green to gray, orange to red, or purple, strongly flattened dorsiventrally, oblanceolate, cuneate, 9–72 × 5.5–20.5 mm, 2.5–5.5 mm thick, apices obtuse, or truncate or shallowly notched, rarely acute. Stem leaves ascending, slightly glaucous, at least when young, and colored like the rosette leaves, 8.5–26 × 3–10 mm, flattened, truncate at base, narrowly oblong to oblanceolate, apices acute or obtuse. Fertile stems green to pink, reddish or orange, 6–28.5 cm tall, nodding or bent in bud, erect in flower and fruit. Inflorescences 4.5–18 × 2.5–6.5 cm, usually densely-flowered, narrowly cylindrical or ellipsoidal panicle-like cymes with 7–17 branches, proximal branches ascending-erect, 12–75 mm long, solitary at inflorescence nodes. Inflorescence bracts resembling stem leaves, but smaller, 4–18 × 1–9 mm, base truncate, tips acute or blunt. Flowers 26–152 per inflorescence, fresh flower diameter 8–12 mm, flowers 5-merous, erect or spreading, calyx green, brown, or red, 2.5–3.4 × 2.4–4.1 mm, sepals fused basally 0.7–1.4 mm, free sepal tips 1.6–2.4 mm long, apex acute to obtuse. Fresh petals fused at base 1.1–2.1 mm; petals 5.0– 7.8 mm long, 1.9–3.2 mm wide at mid-length, pale to medium yellow, sometimes fading to white, midvein orange to red or pink (especially in bud), apices or bases often orange to pinkish or reddish, especially with age. Fresh petal blade v-shaped or trough-shaped in cross section, narrow, at half its length spreading 90° from floral axis, apex with or without a subterminal mucro, if present the mucro 0.05–0.15 mm. Stamens 10, when fresh shorter to longer than petals, filaments white to green or pale yellow, aging red, fresh anthers oblong, 1.1–1.45 × 0.5–0.65 mm, orange to dark red, aging red, orange, brown, or black, papillose at 20×. Nectaries shallowly crescent-shaped, sunken in middle, white to pale yellow, 0.5–1.2 × 0.1–0.3 mm. Ovaries 3.6–6(–7.3) mm, erect, fused 0.6–1.7 mm, maturing into 5 dark brown erect follicles, 5.2–9.2 mm, with erect to slightly curved style remnant forming a narrow beak 1.2–3.5 mm, follicles fused 1.7–3.0 mm at base, containing 9–26 seeds. Seeds medium to dark brown, oblanceolate, shiny, striate, 0.8–1.3 × 0.3–0.5 mm, including stipe 0.05–0.2 mm.

Paratypes: — UNITED STATES. CALIFORNIA. Tehama County: N of Tedoc Gap, 1415 m, 19 June 2011, Wilson & Coberly CWG-10 ( JEPS); Tedoc Mountain , 1450 m, 26 June 2013, Zika 26234 ( CHSC, JEPS, OSC); same site, 26 June 2013, Zika 26238 ( CAS, DAV, HSC, RSA, UCR) ; Little Red Mountain , 1355 m, 24 June 2014, J. K . Nelson 2014-067 & Tate, Rainbow ( OSC, WTU) .

Distribution and ecology: —Currently known from two population aggregates in northwestern Tehama County, California ( Fig. 25 ), in the southern Klamath Ranges ecoregion (Jepson eFlora 2017). Found on gentle to steep rocky slopes, and talus, at southeast, west, northwest, and northeast aspects, in full sun or partial shade of widely scattered pines, on dry reddish peridotite bedrock exposures, at elevations of 1350–1500 m. Associates included Arctostaphylos patula Greene , Aspidotis densa (Brack.) Lellinger , Calocedrus decurrens (Torr.) Florin , Elymus elymoides (Raf.) Swezey , Eriogonum libertini Reveal , E. nudum Benth. , Eriophyllum lanatum , Galium bolanderi A. Gray , Garrya congdonii Eastw. , Minuartia rosei (Maguire & Barneby) McNeill , Packera greenei (A. Gray) W.A. Weber & A. Lӧve , Phacelia corymbosa Jeps. , Pinus jeffreyi , P. sabiniana Douglas ex D. Don , Pyrola picta Sm. , Quercus vaccinifolia Kellogg , Streptanthus barbatus S. Watson , and S. tortuosus Kellogg.

Etymology: — Sedum rubiginosum , or Tedoc stonecrop, was named for the reddish colors found in the fresh and aged petals, as well as the rusty red anthers.

Notes: — Sedum rubiginosum ( Figs. 24 , 32A–F , 43 ) shared many ecological and morphological characteristics of S. kiersteadiae . Both were found on serpentine soils and had a cylindrical inflorescence when well-developed, with red anthers, narrow yellow petals and pink to red colors at the base of the corolla, especially with age. Sedum rubiginosum had more robust growth when sheltered, denser rosettes, more stem leaves, and more flowers than S. kiersteadiae . Sedum rubiginosum was found well to the south of the known range of S. kiersteadiae ( Fig. 25 ). Tedoc stonecrop occasionally produced cleistogamous flowers late in the flowering season.

Figures

FIGURE 1. Dense rosettes on vegetative shoots, without visible internodes between the leaves, were found in most species. A. Sedum flavidum, Trinity Co., California (Zika 26646 & Brainerd). B. Sedum laxum subsp. laxum, Del Norte Co., California (Zika 25927). C. Sedum oblanceolatum, Jackson Co., Oregon (Zika 25636 & Lang). D–E. Sedum rubiginosum, Tehama Co., California. D. Wild plant (Zika 26238). E. Cultivated plant (Wilson & Coberly CWG-10). F. Sedum sanhedrinum, Mendocino Co., California (Zika 26629 & Brainerd).

FIGURE 4. Water stored in the stem leaves appeared to be used in the reproductive effort. Stem leaves withered as flowering progressed. Proximal stem leaves shriveled before those near the inflorescence. A. Sedum laxum subsp. heckneri, Siskiyou Co., California; proximal stem leaves withered, distal still plump (Zika 25640). B. Sedum patens, Del Norte Co., California; proximal stem leaves shriveling during anthesis (Zika 26608 & Brainerd). C–D. Sedum rubiginosum, Tehama Co., California. C. Turgid stem leaves at the initiation of flowering (Wilson & Coberly CWG-10). D. Shriveled stem leaves at late anthesis (Zika 26234). E. Sedum sanhedrinum, Tehama Co., proximal stem leaves withering first (Zika 25970).

FIGURE 11. Petal tips narrow in the distal half; the petals strongly spreading to slightly reflexed. A. Sedum citrinum, Del Norte Co., California (Zika 26620 & Brainerd). B. Sedum kiersteadiae, Trinity Co., California (Zika 26294). C. Sedum patens, Del Norte Co. (Zika 26609 & Brainerd). D. Sedum rubiginosum, Tehama Co., California (Zika 25522 & J.K. Nelson).

FIGURE 15. The color of the petals, anthers, filaments, and carpels often changed after anthesis.A. Sedum albomarginatum, after anthesis petals turned orange-brown; Butte Co., California (Zika 25867). B. Sedum flavidum, buds deep pink especially along the keel, faded to white at anthesis, then aged to a uniform deep pink; Humboldt Co., California (Wilson, Otting, & Darington CWG-118). C. Sedum laxum subsp. laxum, after anthesis green carpels turned dark red, red anthers turned white; Del Norte Co., California (Zika 25936). D. Sedum paradisum subsp. subroseum, after anthesis green carpels turned dark red, yellow anthers turned white; Plumas Co., California (Wilson, Zika & Janeway CWG-15). E. Sedum rubiginosum, after anthesis red-based yellow petals turned pallid; Tehama Co., California (Zika 26234).

FIGURE 24. Inflorescence comparison between Sedum citrinum, S. kiersteadiae, and S. rubiginosum. All three species with narrow spreading yellow petals. A. Sedum citrinum, inflorescence with elongated lower branches, flat-topped, Del Norte Co., California (Zika 25930). B. Sedum kiersteadiae, cylindrical and loose inflorescence, individual flowers easily seen, Shasta Co., California (Zika 26294). C–D. Sedum rubiginosum, cylindrical and dense inflorescence, individual flowers less easily distinguished, Tehama Co., California (Zika 25522 & J.K. Nelson).

FIGURE 25. Distribution of Sedum flavidum, S. kiersteadiae, S. rubiginosum, and S. sanhedrinum, 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 43. Sedum rubiginosum, Tehama Co., California.A–C. Habitat, rocky serpentine slopes.A. Photo: J.K. Nelson (Zika 25522 & J.K. Nelson). B. Wilson & Coberly CWG-10. C. Zika 26238. D–E. Flowering shoots (Zika 25522 & J.K. Nelson). F. Dense rosettes (Zika 26234). G. Oblong overlapping ascending stem leaves, faintly glaucous, with truncated bases (Zika 26238). H. Cylindrical inflorescence in early anthesis, flowers dense (Zika 25522 & J.K. Nelson). I–K. Flowers, petals narrow, acute, spreading, reddish towards base, anthers dark red. I. Typical narrow petals (Zika 25522 & J.K. Nelson). J. Unusually broad petals (Zika 26238). K. Relatively short sepals (Zika 26234).