Ferris's sandwort

Arenaria macradenia S. Watson subsp. ferrisiae Abrams in L. Abrams and R. S. Ferris, Ill. Fl. Pacific States 2: 151. 1944; Eremogone macradenia S. Watson var. ferrisiae (Abrams) R. L. Hartman & Rabeler

Plants tufted, green, not glaucous, with woody base. Stems erect, (10-)20-40(-100) cm, glabrous to stipitate-glandular. Leaves: basal leaves sparse or absent; cauline leaves usually in 5-7 pairs, not significantly reduced; basal blades ascending, needlelike or narrowly linear, 2-6(-7) cm × 0.5-1 mm, ± rigid, herbaceous to subsucculent, apex blunt to spinose, usually glabrous, not glaucous. Inflorescences 10-30(-80)-flowered, diffuse cymes; branches spreading. Pedicels 15-55 mm, glabrous or stipitate-glandular. Flowers: sepals 1-3-veined, ovate to lanceolate or elliptic, 3-4.3 mm, to 5.5 mm in fruit, margins narrow to broad, apex acute to acuminate, glabrous to sparsely stipitate-glandular; petals white or yellowish, oblanceolate to spatulate, 6-9 mm, 1-1.5 times as long as sepals, apex entire or erose; nectaries as lateral and abaxial rounding of base of filaments opposite sepals, 0.3-0.4 mm. Capsules 6-7 mm, glabrous. Seeds reddish brown to blackish, suborbicular to pyriform or ovoid, 1.3-3.2 mm, tuberculate; tubercles low, rounded to conic.

Flowering spring-summer. Pine and oak woodlands, granitic alluvium on foothills and mountain slopes; 1400-2900 m; Ariz., Calif., Nev., Utah.

We now believe that Eremogone macradenia (in the sense of R. L. Hartman 1993) should be split into two species, with E. macradenia var. ferrisiae (Abrams) R. L. Hartman & Rabeler being elevated to species rank (Hartman and R. K. Rabeler 2004), as here. This became particularly obvious when comparing nectary morphology of E. macradenia (rectangular, two-lobed or truncate, 0.7-1.5 mm or narrowly longitudinally rectangular, truncate, densely minutely pubescent with erect to spreading hairs, 0.7-0.8 mm) with that of E. ferrisiae (rounded, 0.3-0.4 mm). Furthermore, the nectary types correlate well with sepal size and inflorescence type, as indicated in the key. This disposition agrees with the conclusions of M. F. Baad (1969).