Ranunculus legerae Tiehm & Lucero, 2024

Tiehm, Arnold & Lucero, Jacqueline, 2024, A New Ranunculus (Ranunculaceae) From Nevada, U. S. A., Journal of the Botanical Research Institute of Texas 18 (1), pp. 7-13 : 8-12

Ranunculus legerae Tiehm & Lucero , sp. nov. ( Figs. 1–4 ).

TYPE. NEVADA. ELKO CO.: Adobe Range , ridge just N of Elko Snobowl , 1.5 air mi NNE of Adobe Summit on Hwy 225 to Mountain City, T35N R54E sec 23, 40.9098°N, 115.86024°W, NAD83, 12 May 2023, A. Tiehm 19335,with J.Nachlinger, S. Frederick,and A. Helmig (HOLOTYPE: RENO; ISOTYPES: ARIZ, ASC, ASU, BM, BRIT, BRY, CAS, COLO, DES, GH, ID, IDS, K, KANU, MO, MONTU, NY, OSC, RM, RSA, TEX, UNLV, UCR, US, UTC, WS, WTU).

Diagnosis.— In Whittemore (1997) and Holmgren & Holmgren (2012), Ranunculus legerae keys to R. adoneus A.Gray. Ranunculus adoneus differs from R. legerae in having leaves 2–3 times dissected into linear segments and petals 8–18 mm long versus leaves that are once divided into broader segments and petals 7.2–10.2 mm long.

Perennial herb, 5–10(12) cm tall, erect when in flower, declined in fruit; roots fibrous; herbage glabrous; stems to 8 per plant, some branched above, not rooting at the nodes; basal leaves 1–4 per stem, petioles 3.5–5.2 cm long, blades 1.5–3.2 cm long, obdeltoid in outline, cuneate at base, ternate, outer leaflets shallowly to deeply (1)2–4-lobed, lobes 1.2–2.4 cm long, 1.8–4.6 mm wide, central leaflet unlobed to deeply cleft; cauline leaf entire to deeply cleft in age, 5.6 mm wide, 9–14 mm long; inflorescence 1–5-flowered, pedicels 2.9–7.1 cm long, erect in flower, arched to curving downward in fruit; sepals 5, green suffused with yellow, ovate, 2–6-nerved, 3.3–5.0 mm wide, 4.2–7.1 mm long; petals 5(–12), yellow aging white, shiny, (2.5) 4.1–6.9 mm wide, (7.2) 8.5–10.2 mm long, multi-veined; nectary scale cleft, 1.0– 1.4 mm long, glabrous, forming a pocket; stamens 25–35, anthers 0.7–1.0 mm long, ovaries numerous; aggregate fruit 5.9–8.5 mm wide, 4.2–6.7 mm tall, depressed-globose; achenes plump, sparsely hairy with erect hairs, ventrally keeled when mature, 1.0– 1.2 mm wide, 1.4–1.6 mm high; beak lateral, erect, 0.6–1.0 mm long.

Specimens examined: All Elko Co., NEVADA. U.S.A. — 18 mi NW of Elko,summit of Round Mountain cut-off, 5,660 ft, 13 May 1937, N.E. Nichols & L. Lund 8 (NA) [image examined]; Adobe Range, Adobe fire of 2016, ca. 0.4 mi N of Barrel Springs, 40.882085°N, 115.882068°W, 21 Apr 2017, S.Frederick 243 (ELKOBLM); on E side of Hwy 225 ca. 10 km N of jct with I-80, 40.880232°N, 115.884224°W,NAD83, 28 Mar 2022, J. Lucero 2, with S. Frederick & R. Hollis (ELKOBLM, RENO, UNLV ); Elko Snobowl ca. 10 km N on 5th St. from downtown Elko , 40.908989°N, 115.856882°W,NAD83, 28 Mar 2022, J.Lucero 3, with S. Frederick & R. Hollis (CAS,ELKOBLM, NY, RENO ); Elko Snobowl ca. 10 km N on 5th St. from downtown Elko , 40.909145°N, 115.857188°W, NAD83, 26 Apr 2022, J.Lucero 6 (CAS,ELKOBLM, RENO ); Adobe Range, ridge line 0.75 air mi SW of Adobe Summit on Hwy 225 to Mountain City, 40.890°N, 115.89349°W,NAD83, 13 May 2023, A. Tiehm 19336,with J. Nachlinger (ASC,CAS,MO, NY, OSC, RENO ,RSA,UCR,UNLV).

Other similar looking western North American Ranunculus are R. jovis A. Nelson , R. glaberrimus var. ellipticus , and R. triternatus . Ranunculus jovis differs in having tuberous roots 2.5–4 mm thick versus fibrous roots in R. legerae . Ranunculus glaberrimus var. ellipticus differs in having the basal leaves entire versus basal leaves three lobed and sometimes farther divided in R. legerae . Ranunculus triternatus differs in having leaves 2–3 times ternate and petals 6–15 mm long versus leaves that are once ternate into broader segments and petals 7.2–10.2 mm long.

Ranunculus legerae has the growth aspect of R. alismaefolius Geyer ex. Benth, but R. alismaefolius has entire leaves.

It is interesting that Ranunculus legerae remained uncollected for 80 years. It is now known from Elko Snobowl, west of Adobe Summit on highway 225 northwest of Elko and some of the immediate surrounding areas. Both areas are within six miles of Elko and easily accessible. The first author admits to having driven highway 225 over Adobe Summit on numerous occasions. The area never looked interesting enough for him to stop and botanize. Ranunculus legerae does flower just after snow melt so muddy conditions would likely be encountered and this could also have deterred collectors.

Etymology.— This plant is named in honor of Elizabeth Anne (Beth) Leger (b. 1974), a dynamic intellectual, excellent mentor, extraordinary professor, and plant lover. Beth received a Ph.D. from the University of California, Davis in 2004. After a postdoctoral position at Stony Brook University in Stony Brook, New York she arrived at the University of Nevada, Reno in 2006 where she is now a Foundation Professor in the Biology Department. She has injected vitality into all the studies, projects, colleagues, and students she has been associated with. Among her lineage of students is the Nevada state botanist for the U.S. Fish & Wildlife Service and the director of the Nevada Division of Natural Heritage.

Beth is a cofounder and director of the Museum of Natural History at the University of Nevada, Reno . The museum includes the herbarium, vertebrate collection, and entomology collection. It is a joint endeavor between the College of Agriculture, Biotechnology & Natural Resources (herbarium) and the College of Science (vertebrate and entomology collections). This two-college support system has provided the collections with a strong backing system that should preserve them for posterity.

Conservation status.— Ranunculus legerae is geographically limited. At present there does not appear to be a threat to its existence. We recommend it be placed in the International Union for Conservation of Nature and Natural Resources’ Vulnerable category. We also recommend that it be placed on Watch Lists for the Nevada Native Plant Society and the BLM, and on the Nevada Division of Natural Heritage’s tract list.

Common name.— An appropriate common name is Elko Buttercup.

Figures

FIG. 1. Ranunculus legerae in flower.Photo by Jan Nachlinger.

FIG. 2.Ranunculus legerae in early and mature fruit.Photo by Jan Nachlinger.

FIG. 3.Ranunculus legerae showing habitat.Photo by Jan Nachlinger.

FIG. 4.Ranunculus legerae illustration prepared by Annaliese Miller.Drawn from Tiehm 19335.