Sedum obtusatum Gray (1868: 342)

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

10. Sedum obtusatum Gray (1868: 342) . Figs. 5D , 13B , 36

Gormania obtusata (A.Gray) Britton in Britton & Rose (1903: 29). Cotyledon obtusata (A.Gray) Fedde in Schumann & Fedde (1904: 827). Echeveria obtusata (A.Gray) Nelson & Macbride (1913: 476).

Type: — UNITED STATES. California. [Mariposa County], Mount Hoffmann , 3290 m, [24 June 1863], W. H. Brewer 1678 (lectotype, designated by Clausen [1975: 371], GH; isolectotype, US).

Gormania burnhamii Britton in Britton & Rose (1903: 30, as “burnhami”). Cotyledon burnhamii (Britton) Fedde in Schumann & Fedde (1904: 827). Sedum burnhamii (Britton) Berger (1930: 451 , as “burhamii”).

Type: — UNITED STATES. California. Tuolumne County, from Lake Eleanor to Lake Vernon , along trail, 16 July 1894 [ US sheet says 1884, in error], S. H. Burnham s.n. (lectotype, designated by Clausen [1942: 31], NY; isolectotypes, BH [2 sheets, one a fragment], POM, US [fragment]) .

Gormania hallii Britton in Britton & Rose (1903: 29). Cotyledon yosemitensis Fedde in Schumann & Fedde (1904: 828). Echeveria brittonii Nelson & Macbride (1913: 476). Sedum hallii (Britton) Praeger (1921: 241) . Sedum obtusatum A.Gray var. hallii (Britton) Smiley (1921: 213) .

Type: — UNITED STATES. California: [Tuolumne Co.], Yosemite National Park, vicinity of Tuolumne Meadows , 2590–2895 m, July 1902, H. M. Hall & E. B. Babcock 3545 (lectotype, designated by Clausen [1942: 31], NY; isolectotypes, DS, F, GH, MO, POM, RM internet image, UC, US [2 sheets, one a fragment]).

Sedum rubroglaucum Praeger (1919: 51) .

Type: — UNITED STATES. California: [Mariposa Co.], Yosemite National Park, Four Mile Trail [formerly known as Short Trail] to Glacier Point, cracks in granite, ca. 7000 feet, 4 July 1940, R. V. Moran 539 (neotype, designated by Zika [2015: 4], YM; isoneotype, UCSB). Illustrated as fig. 125 ( Praeger 1921: 219).

Asa Gray (1868) listed three specimens when he described Sedum obtusatum , all mounted on one sheet at GH, and all syntypes. Two specimens were Bolander 4960 and Brewer 1920, cited below. Clausen (1975: 371) typified the name by choosing the third specimen as the lectotype, Brewer 1678 ( GH), a gathering from Mount Hoffmann, which is a peak listed in modern references as 10771 feet (3283 m) in elevation, in Yosemite National Park. The specimen label says only: “Mount Hoffmann, 10800 feet [3292 m], Geological Survey of California, 1860–62, W. H. Brewer 1678 ” ( GH 42519). Amy Kasameyer (pers. comm., UC) found that Brewer had these additional notations in his collecting book for 1678: “coll. 24 June 1863, Mount Hoffmann, the leaves of this seen abundant on the higher granite rocks, but flowers scarce, dull yellow.”

Additional specimens examined: — UNITED STATES. CALIFORNIA. Alpine County: East Blue Lake , 2470 m, 15 August 1933, Wolf 5311 ( CAS, DS, RSA [3 sheets]) ; Blue Lakes , 1 July 1961, Hutchison 2141 ( BH, SD) ; NE of Hermit Valley , 2225 m, 13 July 1956, Everett & Balls 22145 ( RSA, WS) . El Dorado County: Angora Peak , 2530 m, 14 July 1913, Smiley 40 ( GH) ; Emerald Bay, Lake Tahoe , 4 June 1934, Maguire, Maguire & Maguire 15168 ( BH) ; above E shore Echo Lake , 2134 m, 25 July 1943, Robbins 1320 ( RSA) ; above Glen Alpine , 22 July 1950, Moran 3449 ( BH) . Fresno County: Margaret Lakes area , 8 August 1954, Quibell 4203 ( OSC, RSA, WS) ; above Huntington Lake , 2316 m, 10 August 1963, Howe s.n. ( SD) ; Wren Peak , 2865 m, 1 July 1990, Shevock 11918 et al. ( CAS, RSA); Monarch Divide , SSW of Mount Harrington , 3000 m, 2 July 1990, Ross 3042 ( CAS, RSA) . Madera County: Shuteye Mountain , 2470 m, 19 July 1914, Smiley 569 ( GH) ; canyonside below Shadow Lake , ca. 2500 m, 10 July 1977, Moran 24301 ( SD) ; Shadow Lake Trail 1 mile from Agnew Meadow , 2469 m, 18 July 1962, Reveal & Reveal 429 ( RSA, WTU) . Mariposa County: Vernal Falls , on granite rocks, 14 July 1866, H. N. Bolander 4960 ( GH, K internet image, UC, US, YU internet image) (syntype) ; Yosemite National Park, SE slope of Mount Hoffmann , 2745 m, 7 July 1940, Clausen 4823 & Trapido ( BH [2 sheets]) ; Yosemite National Park, above Nevada Falls , 1525 m, 4 July 1940, Clausen 4801 & Trapido ( BH [2 sheets]) ; Yosemite National Park, top of Half Dome , 25 June 1942, Roos 1748 ( UCR) ; between Vernal and Nevada Falls , 1590 m, 24 June 1964, Clausen 641018 ( BH) ; same site, 1604 m, 24 June 1964, Clausen 641019 ( BH) , Clausen 641010 ( BH) ; Yosemite National Park , NE of Wawona, 1970 m, 12 July 1964, Clausen 641061 ( BH) , Clausen 641060 ( BH) ; W of Lake Tenaya , 2545 m, 16 June 2013, Van Susteren JVS-13-5 ( CHSC, TO) . Mono County: Barney Lake , 2530 m, 21 July 1940, Munz 16142 ( RSA, WTU) ; E of Sonora Pass , 2590 m, 23 July 1932, Pierson 10408 ( RSA) ; E of Bennetville Mine Tunnel , 2990 m, 7 September 1967, Chafin 23 ( OSC, SD, WTU) ; Sonora Pass , E slopes 2605 m, 16 June 1976, Denton 3921 ( OSC, WTU) ; E of Tioga Pass , 2600 m, 17 June 1976, Denton 3923 ( OSC, WTU) ; near Tioga Pass , 2940 m, 17 June 1976, Denton 3930 ( OSC, WTU) ; trail on Green Creek , 2535 m, 25 June 2013, Janeway 11160 ( CAS, DAV, HSC, KANU) . Nevada County: Yuba Pass , 1753 m, 28 May 1961, Uhl 960 ( BH) ; between Lake Spaulding and Highway 20, 1615 m, 15 July 1978, Howe s.n. ( SD) ; above Donner Lake, toward Donner Pass , 7 August 1903, Heller 7105 ( BM, E n.v., GH, K internet image; LE n.v., PH n.v., POM) ; N of Donner Pass , 2035 m, 29 June 2012, Wilson & Otting CWG-110 ( MO, US) ; road to Bowman Lake , 1640 m, 30 June 2012, Wilson & Otting CWG-111 ( NY, RENO, UBC, WTU) ; Discovery Trail , 1425 m, 30 June 2012, Wilson & Otting CWG-112 ( JEPS) ; SW of Summit Lake , 2210 m, 28 June 2013, Zika 26271 ( DAV, WTU) . Nevada / Placer County border: Donner Pass , 2165 m, 15 June 1976, Denton 3917 ( OSC, WTU) . Placer County: Donner Pass , 2165 m, 28 May 1961, Uhl 961 ( BH) ; Donner Lake , 1875 m, 15 June 1976, Denton 3909 ( WTU) ; Palisade Lake , 2105 m, 15 June 1976, Denton 3919 ( WTU) . Sierra County: E of Keystone Mountain , 1890 m, 1 July 1994, Ahart 7437 ( JEPS) ; Jackson Meadows Reservoir , 1850 m, 28 June 2013, Zika 26267 ( OSC, WTU) .

Tulare County: Monarch Lakes Trail , 2590 m, 19 July 1951, J. T. Howell 27978 ( RSA); E slope Moses Mountain , 2700 m, 23 July 1982, Shevock 9950 ( RSA). Tuolumne County: peak near Sonora Pass, dry exposed rocks near summit, 12000 feet, 17 July 1863, W. H. Brewer 1920 ( GH, UC) (syntype) ; summit of hill south of Camp 127, 21 July 1863, W. H. Brewer ( US internet image, YU internet image) ; Sonora Pass , 1980 m, 18 July 1938, Wiggins 8945 ( GH, RSA, WTU) ; same site, 2438 m, 3 July 1961, Hutchison 2154 ( BH, SD) ; same site, 1828 m, 2 July 1961, Hutchison 2152 ( BH) ; Yosemite National Park , Lambert Dome , 2621 m, 8 July 1940, Clausen 4824 & Trapido ( BH [2 sheets]) ; same site, 2835 m, 8 July 1940, Clausen 4832 & Trapido ( BH [2 sheets]), Clausen 4832a & Trapido ( BH) ; Emigrant Lake , 2680 m, 12 August 1942, Wiggins 10126 ( WTU) ; W of Sonora Pass , 2925 m, 17 June 1966, Wallace 623 ( RSA) ; WSW of Sonora Pass, 12 August 2012, Brainerd 2073 & Zika ( F) ; Yosemite National Park , W of Vernon Lake, 2040 m, 6 July 1940, Clausen 4810 & Trapido ( BH [3 sheets]) ; Tuolumne Meadows , 2665 m, 17 June 1976, Denton 3933 ( WTU) ; Tioga Pass , 2240 m, 17 June 1976, Denton 3937 ( OSC, WTU) . NEVADA. Mineral County: Aurora , 2285 m, 10 July 1929, Wright s.n. ( SBBG) ; [county not specified], near Carson City , 1864, Anderson 271 ( GH fragment) .

Distribution and ecology:— Distributed for 400 km in the northern, central, and southern high Sierra Nevada ecoregions (Jepson eFlora 2017), south of the Middle Yuba River in Sierra County, south to Tulare County, California, at elevations of 1450–3550 m ( Fig. 37 ). Recent searches in central western Nevada failed to relocate the species (A. Tiehm, pers. com.)

Notes: — Sedum obtusatum ( Fig. 36 ) had obovate, obtuse to retuse rosette leaves and elliptic to oblong or narrowly obovate stem leaves. The sepals were acute and relatively long, varying from (40–)50–75(–80)% as long as the petals. The petals were bright yellow to pale yellow, acute, relatively broad distally, and ascending at anthesis. The fresh anthers were yellow, aging brown or white.

Sedum obtusatum was most similar to S. paradisum subsp. subroseum , and the easiest way to separate them, besides geographic range, was the color of the flowers, which were always pale to deep yellow in S. obtusatum , and white fading to pink in S. paradisum subsp. subroseum . The latter was restricted to slopes north of the Middle Yuba River; S. obtusatum to the south of Middle Yuba River ( Fig. 37 ). In the Sierra Nevada mountains south of Lake Tahoe, S. obtusatum was the only representative of section Gormania . The stem leaves were more uniformly elongate in S. paradisum than they were in S. obtusatum , which generally shows longer proximal stem leaves, and some reduction in the length of distal stem leaves. In addition, there was a tendency for the flowers of S. paradisum to be straight-sided in side view, below the spreading of the petals; S. obtusatum flowers often showed a slight constriction between the sepal apex and spreading petal tips, so that in side-view the flower was somewhat hourglass-shaped.

Figures

FIGURE 5. Stem leaves longer than wide, with a truncated base, were typical of most species of Sedum section Gormania. The stem leaves were commonly broadly obovate to elliptic or oblong, and were flattened or nearly cylindrical.A. Sedum citrinum, Del Norte Co., California (Zika 26185). B. Sedum laxum subsp. laxum, Del Norte Co. (Zika 25927). C. Sedum oblanceolatum × oregonense, Siskiyou Co., California (Zika 25647B). D. Sedum obtusatum, Nevada Co., California (Zika 26271). E–F. Sedum oregonense, Josephine Co., Oregon (Zika 25657). G. Sedum sanhedrinum, Lake Co., California (Zika 26639 & Brainerd).

FIGURE 13. Distal half of the petals broad and ascending. A. Sedum flavidum, Trinity Co., California (J.K. Nelson JKN-12-2). B. Sedum obtusatum, Nevada Co., California (Zika 26271). C. Sedum oregonense, Del Norte Co., California (Otting CWG-122). D. Sedum paradisum subsp. subroseum, Plumas Co., California (Wilson, Janeway & Zika CWG-14).

FIGURE 36. Sedum obtusatum. A. Habit, showing numerous dense rosettes, Nevada Co., California (Wilson & Otting CWG-110). B. Stem leaves, longer than wide, truncated bases, Sierra Co., California (Zika 26267). C. Young inflorescence axes bent, pre-anthesis, Nevada Co. (Zika 26271). D. Inflorescences cylindrical to capitate or flat-topped (Wilson & Otting CWG-110). E–F. Flowers. E. Typical bright yellow flowers, yellow anthers, elongated sepals, Mono Co., California (Janeway 11160). F. Pallid flowers, ascending petals with acute tips (Zika 26271).

FIGURE 37. Distribution of Sedum obtusatum, S. oregonense, S. paradisum subsp. paradisum, S. paradisum subsp. subroseum, based on verified herbarium specimens.