Monographs Details: Minuartia stolonifera T.W.Nelson & J.P.Nelson
Authority: Nelson, T. W. & Nelson, J. P. 1991. Minuartia Stolonifera (Caryophyllaceae): A New Species from the Serpentine of ScottMountain, Siskiyou County, California. Brittonia. 43 (1): 17-19.
Family:Caryophyllaceae
Description:Species Description - Perennial; perennial stems stolon-like, 6-20 cm long from a woody tap root; annual stems from nodes of perennial stems, 2 to several, erect, 9-16 cm high, gray-green, glandular-puberulent near inflorescence; primary leaves shorter than internodes, strict, linear-subulate, 3-nerved, 5-9 mm long, 0.5-0.9 mm wide, gray-green, glandular-puberulent; secondary leaves inconspicuous, clustered in axils of primary leaves; inflorescence an open cyme, 4-9 cm long, glandular- puberulent; sepals narrowly ovate-lanceolate, 1-3 nerved, 3-4 mm long, slightly glandular-pubescent, gray-green with purplish apices, margins scarious; petals white, broadly linear to narrowly oblong-elliptic, 5-7 mm long, 2-3 mm longer than sepals; capsule 3.5-5 mm long, dehiscent by 3 valves

Discussion:

Caulibus foliisque parce glandulosis petalisque sepala superantibus M. rosei (Maguire & Barneby) McNeill similis, ab ea foliis primariis internodio longioribus secundariis inconspicuis diversa. Caules stoloniformes 6-20 cm, aerei 11 cm longi, inflorescentiam versus glanduloso-pubescentes.

TYPE: UNITED STATES. CALIFORNLA. Siskiyou Co.: T40N, R8W, S 24, Elev. 4000 ft, along S side of State Route 3, 3.1 mi N of Scott Mountain Pass. Rocky openings in Jeffrey pine woodland on serpentine, 19 Jun 1985, Nelson & Nelson 7839 (HOLOTYPE: CAS; ISOTYPES: BRY, HSC, MO, NY, RM, US, WTU).

Additional specimens seen: UNITED STATES. CALIFORNIA. Siskiyou Co.: Jeffrey pine woodland along State Route 3, 3 mi N of Scott Mountain Pass at junction with road 40N03, 26 May 1979, Nelson & Nelson 4723; type locality, 15 Jun 1979, Nelson & Nelson 4851; T40N, R8W, S 24 & 25, Elev. 4400 ft, along State Route 3, 2.2 mi N of Scott Mountain Pass, serpentine woodland, 30 Jul 1982, Nelson & Nelson 7312; W side of State Route 3, 2.4 mi N of Scott Mountain Pass, just S of junction with road 40N03, Jeffrey pine woodland on serpentine, Elev. 4500 ft, 29 Jul 1983, Nelson & Nelson 7500. Collections to be distributed.

There is no consensus among North American botanists on the circumscription of Arenaria L.; that is whether to define it broadly or to recognize Minuartia and other segregates. Most American botanists follow Femald's (1919) and Maguire's (1951) broad generic concept of Arenaria. We have chosen to follow McNeill's (1962, 1980) and McNeill and Basset's (1974) treatment of the Alsinoideae in which Minuartia is separated from Arenaria. Also, this is the concept being fol- lowed by Hartman (pers. comm.) in the forthcoming revision for the Jepson Manual.

As with Minuartia decumbens T. W. Nelson & J. P. Nelson (Nelson & Nelson, 1981) and M. rosei (Maguire & Bameby) McNeill, M. stolonifera is restricted to serpentine-derived soils. To date it has been found only in the Scott Mountain Pass area of south-central Siskiyou County. It grows on upper slopes in Jeffrey pine woodlands, in association with Lupinus lapidicola A. A. Heller, Viola halli A. Gray, Astragalus whitneyi var. siskiyouensis (Rydb.) Bameby, Horkelia daucifolia (Greene) Rydb., Galium serpenticum ssp. scoticum Dempster & Ehrend, and Crepis pleurocarpa A. Gray. Minuartia stolonifera can be distinguished easily from the other perennial species of the genus found in California's North Coast Ranges. Minuartia nuttallii ssp. gregaria (A. A. Heller) McNeill is densely gladular-pubescent throughout while the other taxa are only slightly glandular in the inflorescence. Both M. rosei and M. decumbens have leaves that exceed the in- ternodes and well developed secondary leaves, giving the plant stems a congested appearance; while in M. stolonifera the leaves are shorter than the internodes and the secondary leaves are poorly developed, giving the plants a more open appearance