Crossosoma

Nuttall
Proc. Acad. Nat. Sci. Philadelphia 4: 7. 1848.
Etymology: Greek krossos, fringe or tassel, and soma, body, alluding to aril
Treatment appears in FNA Volume 9. Treatment on page 11. Mentioned on page 10.

Shrubs or, occasionally, trees. Stems densely branched; twigs tan or reddish tinged, ± angled, not decurrently ridged, smooth, not punctate, glabrous; bark gray to grayish tan. Leaves alternate, sometimes appearing fasciculate on short shoots; stipules absent; petiole absent or indistinctly short, not decurrent; blade narrowly elliptic to elliptic or narrowly oblanceolate to obovate, occasionally spatulate, base cuneate or, more commonly, attenuate, margins entire, apex tip rounded to blunt, usually mucronate, midvein usually apparent (at least abaxially), sometimes 3–5 pairs of arched-ascending secondary veins and fine network of tertiary veins also apparent (especially upon drying), glaucous, glabrous. Inflorescences terminal on short shoots or apparently axillary, flowers solitary. Pedicels short to long. Flowers: hypanthium with fleshy, crenately lobed nectar disc; sepals 5, ovate to nearly circular, ± cucullate, margins narrowly hyaline, glaucous, glabrous; petals 5, usually white, sometimes ± purplish tinged with age, narrowly lanceolate, elliptic, or oblanceolate, 9–18 mm; stamens 15–50 in 2–4 series, filaments inserted on disc, usually longer than anthers; carpels 2–9, distinct, short-stipitate; stigmas oblique, capitate. Follicles (1–)2–9, ± cylindric, turgid, adaxial surface mostly curved prior to dehiscence, apex sometimes ± beaked, finely transversely verrucose or indistinctly reticulate with rounded ridges, glabrous; adaxial suture cartilaginous. Seeds 4–22 per follicle, brown to nearly black (finely mottled), usually reniform, sometimes nearly spheric, slightly to moderately flattened, shiny, smooth to faintly striate, rugulose, or verruculose; arils white or pale yellow, deeply fimbriate, seeds and arils often ± coherent. x = 12.

Distribution

sw United States, nw Mexico.

Discussion

Species 2 (2 in the flora).

Selected References

None.

Key

1 Sepals 4–5 mm; leaves 5–15(–25) mm, mostly fasciculate. Crossosoma bigelovii
1 Sepals 8–12 mm; leaves 20–90 mm, mostly well spaced. Crossosoma californicum