Stillingia paucidentata
Proc. Amer. Acad. Arts 14: 298. 1879.
Herbs, perennial, with thick taproot. Stems fascicled, erect, branching scattered proximally and crowded distally, (1.4–)2–3.5(–4) dm. Leaves alternate; stipules absent; petiole absent; blade linear, 2–4(–6) × 0.1–0.3(–0.4) cm, base acute, margins entire or remotely denticulate, teeth without prominent blackened tips, not incurved, apex usually acute, rarely acuminate; venation not prominent. Inflorescences sessile or rarely short-pedunculate, 6–-7 cm; staminate flowers crowded distally, 1 per node; pistillate flowers 3–5, crowded; bracts broadly ovate, to 1.5 mm, apex mucronulate or acuminate, glands patelliform, sessile, to 1.3 mm diam. Staminate flowers: calyx to 1 mm. Pistillate flowers: sepals 0; styles connate only at base, to 4 mm. Capsules oblate, 3 × 4 mm, deeply 3-lobed; lobes of gynobase 1.5–2 mm; columella persistent. Seeds brown, often mottled, ovoid, 2.3 × 1.3 mm, smooth; caruncle minute.
Phenology: Flowering Mar–May; fruiting May–Jun.
Habitat: Sandy flats, dry slopes.
Elevation: 0–1500 m.
Discussion
Stillingia paucidentata is widespread in the Mojave Desert and extends into the Sonoran Desert in central Riverside County. It was reported from Arizona by T. H. Kearney and R. H. Peebles (1942, 1960) solely on the basis of the type (Palmer 517), purportedly collected in 1876 in the “Colorado Valley, near mouth of Williams River.” R. McVaugh (1943b) and McVaugh and Kearney (1943) have cast doubt on whether a number of Palmer collections with labels indicating 1876 were actually made in Arizona; they did not discuss Palmer 517 specifically. There appear to be no other specimens or reports of this species from Arizona. Because S. paucidentata is known from numerous collections in eastern San Bernardino County, California, its presence in bordering areas of Arizona cannot be completely discounted.
Selected References
None.