Sedum patens Zika, 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

13. Sedum patens Zika , sp. nov. Figs. 3A–B , 4B , 8E , 11C , 40G–M , 42

Species insignis Sedum laxum eximie affinis sed petalis niveis apicibus patentibus necnon antheris luteis notabilis.

TYPE: — UNITED STATES. California: Del Norte County, SE of Bald Hill , 90 m, 9 June 2015, P . F . Zika 27047 (holotype, WTU; isotypes, CAS, GH, MO, NY, OSC, RSA, UC) .

Rhizomes and stolons to 35 cm long, 3.7–5.8 mm diameter; sterile leafy shoots 1–7. Rosettes 20–48 mm diameter. Rosette leaves mostly densely arranged without visible internodes, in shady or sheltered situations sometimes loosely arranged with visible internodes, only faintly glaucous, at least when young, green to gray-green, red, or purple, strongly flattened dorsiventrally, obovate to widely obovate, cuneate, 10–35 × 12–21 mm, 3–6 mm thick, apices obtuse, truncate or, more commonly, shallowly notched. Stem leaves ascending, slightly glaucous, at least when young, and colored like the rosette leaves, 11–15 × 7–11 mm, 2–3.5 mm thick, flattened, truncate at base, oblong–oblanceolate, obovate, or broadly obovate, apices obtuse. Fertile stems pink to reddish or green, 7–29 cm tall, nodding or bent in bud, usually erect or leaning in flower and fruit. Inflorescences 2.5–11.5 × 3–8 cm, flat–topped cymes with 3–12 branches, proximal branches ascending or spreading, 20–115 mm long, solitary at inflorescence nodes. Inflorescence bracts smaller and narrower than stem leaves, 4–10 × 1–4 mm, bases truncate, tips acute. Flowers (10–)15–31 per inflorescence, fresh flower diameter 10–14 mm (6–7 mm before spreading), flowers 5–merous, erect, calyx green, 3.7–4.9 × 3.4–4.3 mm, sepals fused basally 0.7–1.1 mm, free sepal tips 2.6–3.5 mm long, apex narrowly acute to acuminate. Fresh petals fused at base 1.9–2.4 mm; petals 8.5–12.1 mm long, 2.4–2.8 mm wide at mid-length, white or greenish-white, and same color at base and on midvein, aging to dirty white. Fresh petal blade v-shaped or trough-shaped in cross section, relatively narrow, distal half oblong then gradually narrowing, narrowly deltoid, at half its length slightly to strongly spreading 45–90° from floral axis, apex apiculate with subterminal mucro 0.3–0.5 mm. Stamens 10, when fresh shorter than to equaling petals, filaments greenish-white or white, similar in color with age, fresh anthers oblong to lance-oblong, 1.2–1.9 × 0.5–0.7 mm, yellow, aging yellow, papillose at 20×. Nectaries shallowly crescent-shaped, sunken in middle, white, 0.6–1 × 0.3–0.4 mm. Ovaries 4.6–6.1 mm, erect, fused 1–1.3 mm, maturing into 5 dark brown erect follicles, 5–6 mm, with erect to slightly curved style remnant forming a narrow beak 0.9–1.5 mm, follicles fused 1 mm at base, containing 10–12 seeds. Seeds medium brown, oblanceolate, shiny, striate, 1–1.2 × 0.3 mm, including stipe 0.2 mm.

Paratypes: — UNITED STATES. CALIFORNIA. Del Norte County: South Fork Smith River , 120 m, 8 July 1950, W. B. Cooke & V. G. Cooke s.n. ( UC) ; ENE of Bald Hill , 125 m, 24 June 2012, Zika 25935 ( OSC, WTU) ; same site, 9 June 2014, Zika 26608 & Brainerd ( OSC, SD, WTU) ; SE of Bald Hill , 120 m, 9 June 2015, Zika 27063 ( RSA, WTU) ; SSE of Canthook Mountain , 180 m, 10 June 2014, Zika 26623 & Brainerd ( DAV, MO, OSC, WTU) ; W of Canthook Mountain , 155 m, 9 June 2014, Zika 26609 & Brainerd ( CAS, CHSC, OSC, WTU) ; same site, 9 June 2015, Zika 27064 ( CHSC, WTU) ; same site, 9 June 2015, Zika 27065 ( HSC, WTU) ; SSE of Craigs Creek Mountain , 100 m, 16 May 2015, Zika 26987 ( UCR, OSC) ; same site, 9 June 2015, Zika 27060 ( JEPS, WTU) ; same site 17 May 2015, Zika 26999 ( WTU) .

Distribution and ecology: —The documented distribution of Sedum patens was along the South Fork of the Smith River, in the Klamath Ranges of southern Del Norte County, California ( Fig. 22 ). Populations varied from 90–200 m elevation, on dry or damp steep open rocky slopes, talus, and cliffs with a south, east or north aspect, on ultramafic soils or bedrock. Most plants were in full sun, but some were in sheltered crevices and in partial shade. One colony with numerous shoots was growing on wood, in a knothole on a large toppled tree on a steep slope ( Fig. 42E ). The northern-most populations were just south of and upslope from the coastal redwood association, dominated by Sequoia sempervirens (D. Don) Endl. , in the canyon bottoms. Very little was known about S. patens , which was first collected in 1950. A more complete assessment of its distribution awaits further field surveys in steep trail-less terrain. We noted seven populations, which varied in size from fewer than 50 plants to approximately 1000 individuals. Photos of plants in the adjacent Mill Creek drainage to the west, on or near state park land, also suggested S. patens , but no specimens were seen.

Some common associates included Achillea millefolium , Adiantum aleuticum (Rupr.) C.A. Paris , Aspidotis densa (Brack.) Lellinger , Cerastium arvense L., Carex mendocinensis Olney ex W. Boott , Castilleja pruinosa Fernald , Chamaecyparis lawsoniana (A. Murray) Parl. , Elymus glaucus Buckley , Erigeron foliosus Nutt. , Eriophyllum lanatum (Pursh) J. Forbes , Festuca californica Vasey, F. roemeri (Torr. & A. Gray) Greene var. klamathensis B.L. Wilson , Frangula californica (Eschsch.) A. Gray subsp. occidentalis (Greene) Kartesz & Gandhi , Holodiscus discolor , Iris thompsonii R.C. Foster , Montia parvifolia (Moc. ex DC.) Greene , Poa piperi Hitchc. , Polystichum imbricans (D.C. Eaton) D.H. Wagner , Pseudotsuga menziesii (Mirb.) Franco , Rhododendron occidentale (Torr. & A. Gray) A. Gray , Schedonorus arundinaceus (Schreb.) Dumort. , Silene serpentinicola T.W. Nelson & J.P. Nelson, Tauschia glauca (J.M. Coult. & Rose) Mathias & Constance , Toxicodendron diversilobum (Torr. & A. Gray) Greene , Triteleia laxa Benth. , and Whipplea modesta Torr.

Etymology: — Sedum patens , or Smith River stonecrop, was named for the widely spreading petals.

Notes:— Sedum patens ( Figs. 40G–M , 42 ) had narrow white acuminate petals and yellow anthers. In Sedum section Gormania only two taxa displayed occasional stem leaves with decurrent bases, S. patens and S. laxum subsp. laxum . In the Smith River basin and in coastal Oregon, S. laxum subsp. laxum often showed truncate leaf bases, while in Josephine County Oregon (and elsewhere), S. laxum subsp. laxum often displayed strongly decurrent leaf bases, sometimes completely lacking truncate stem leaf bases. Most plants of S. patens had truncate leaf bases, but the presence of some with decurrent bases ( Fig. 42J ) suggested an alliance with S. laxum , or possible hybridization. Both taxa share long narrow acuminate-tipped petals. Sedum patens was easily separated from S. laxum by the yellow anthers and spreading white petals; S. laxum subsp. laxum and subsp. heckneri had dark red anthers and erect, usually pink petals, occasionally whitish above or on the margins, and pink at the base or center.

In cultivation we noticed a pungent honey-like odor to the flowers, detectible from a few meters and persisting after dark, suggesting moth pollinators.

Figures

FIGURE 3. Species typically with dense rosettes in full sun occasionally formed loose rosettes in sheltered microsites, often associated with shade, talus, or protected crevices. A–B. Sedum patens vegetative shoots, Del Norte Co., California. A. Typical dense form (Zika 26987). B. Loose form (Zika 26609 & Brainerd). C–D. Sedum paradisum subsp. subroseum, Sierra Co., California (Zika 26279). C. Typical dense form. D. Loose form.

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 8. The central basal flower in a cyme was the largest and opened first.A. Sedum albomarginatum, Plumas Co., California (Zika 25865). B. Sedum citrinum, Del Norte Co., California (Zika 26201). C. Sedum laxum subsp. laxum, Del Norte Co. (Zika 25927). D. Sedum paradisum subsp. paradisum, Shasta Co., California (Lindstrand III & Van Susteren NSR-01). E. Sedum patens, Del Norte Co. (Zika 26609 & Brainerd).

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

FIGURE 40. A–F. Sedum paradisum subsp. subroseum. A. Habit, showing stolons and dense rosettes, and consistently elongated proximal and distal stem leaves (Zika 26283). B. Flower, side view, showing ascending petals and elongated sepals. C. Flower, top view, showing broad upper petal and acute tips. B–C, E–F. Zika 26279. D. Petal tip enlargement, showing subterminal mucro projecting on the right side, and the hooded petal tip on the left side (Zika 26283). E. Rosette leaf. F. Stem leaf, with truncated base; in the field the stem leaves were often a dull gray, but varied to green or pink. G–M. Sedum patens. G. Habit, showing loose rosettes, stem leaves longer than wide, and widely branched inflorescence. H. Flower, side view, showing spreading petals. I. Flower, top view, showing narrow gradually tapered upper half of petals, and acuminate tips. G–I. Zika 26609 & Brainerd. J. Enlargement of petal tip, showing subterminal mucro projecting on right, hooded petal tip on left (Zika 26608 & Brainerd). K. Dehisced follicles with attenuated apex. L. Rosette leaf. M. Stem leaf, with truncated base. K–M. Zika 25935.

FIGURE 42. Sedum patens, Del Norte Co., California. A–E. Serpentine habitat. A. Talus (Zika 26987). B. Streambank ledges (Zika 27063). C. Type locality, rocky slope (Zika 27047). D. Talus (Zika 27060). E. On wood, in a knothole on a fallen tree on a talus slope (Zika 26987). F. Loose rosettes from a sheltered microsite (Zika 27047). G. Typical dense rosettes in sunny sites (Zika 27060). H. Rosette leaves, bottom row; stem leaves, upper row (Zika 26987). I. Typical stem leaves, bases truncated (Zika 26609 & Brainerd). J. Unusual stem leaves, bases decurrent (Zika 26609 & Brainerd). K. Nodding or arching inflorescences, pre-anthesis (Zika 26987). L–M. Flat-topped inflorescences. L. Zika 27047. M. Zika 26609 & Brainerd. N–O. Flowers, white acuminate narrow petals, spreading at maturity, anthers yellow (Zika 26609 & Brainerd). P. Dehisced follicles with attenuated apex (Zika 26999).