Prickly Sandwort

Some specimens from north-central California and southwestern Oregon have been named Arenaria pumicola var. californica. R. L. Hartman (1993) considered those plants to be robust forms of Eremogone aculeata, not deserving formal recognition. Based on work by M. F. Baad (1969), they warrant further study.

Reports of Eremogone aculeata from Arizona, New Mexico, and Wyoming are erroneous.

Plants strongly mat-forming, glaucous, often with woody base. Stems erect, 7-25(-30) cm, densely stipitate-glandular distally. Leaves: basal leaves persistent; cauline leaves in 1-3 pairs, abruptly reduced distal to lowest pair; basal blades ascending or often arcuate-spreading, needlelike, (0.5-)1-2.5(-3.5) cm × 0.5-1.5 mm, rigid, herbaceous, apex spinose, glabrous to puberulent, glaucous. Inflorescences 5-25+-flowered, open cymes. Pedicels 3-25 mm, stipitate-glandular. Flowers: sepals 1-3-veined, lateral veins less developed or all obscure, ovate, 3-4.5 mm, to 6 mm in fruit, margins broad, apex usually obtuse to rounded, abruptly acute, sparsely to densely stipitate-glandular; petals white, obovate to oblanceolate, 4.5-10 mm, 1.5-3 times as long as sepals, apex rounded; nectaries as lateral and abaxial rounding, with slight lateral expansion, at base of filaments opposite sepals, 0.3 mm. Capsules 5-9 mm, glabrous. Seeds yellowish tan to gray, ellipsoid-oblong, 1.8-2.5(-3.2) mm, tuberculate; tubercles rounded, elongate. 2n = 22.

Calif., Idaho, Mont., Nev., Oreg., Utah, Wash.

Flowering summer-early fall.

Rocky slopes, alluvium, volcanic areas; 1500-3400m.

Arenaria aculeata S. Watson, Botany (Fortieth Parallel), 40. 1871; A. fendleri A. Gray var. aculeata (S. Watson) S. L. Welsh; A. pumicola Coville & Leiberg var. californica Maguire

Eremogone aculeata (syn. Arenaria aculeata) is a species of flowering plant in the family Caryophyllaceae known by the common name prickly sandwort. It is native to the western United States, where it grows in the southern sagebrush steppe, mountainous areas, and volcanic soils, as well as on rocky slopes.

This is a mat-forming perennial herb growing in clumps of waxy foliage on short, hairy, glandular stems. The leaves are very thin and pointed, somewhat needlelike, and up to 3 or 4 centimeters long. The inflorescence is an open array of flowers with five lance-shaped to oval white petals each one half to one centimeter long. The fruit is a toothed capsule containing several small yellowish seeds.