3. Peritoma jonesii (J. F. Macbride) H. H. Iltis, Novon. 17: 449. 2007.
Cleome lutea Hooker var. jonesii J. F. Macbride, Contr. Gray Herb. 65: 39. 1922; C. jonesii (J. F. Macbride) Tidestrom
Annuals, 50-100(-200) cm. Stems sparsely branched distally; glabrous or glabrate. Leaves: petiole 1.5-4.5 cm; leaflets 5, (proximal ones sometimes early deciduous), blade linear to elliptic, 1.5-4(-6) × 0.4-1.3 cm, margins serrate , apex long-acuminate, surfaces glabrous. Racemes 1-3 cm (6-40 cm in fruit); bracts unifoliate, obovate to spatulate, 2-15 mm. Pedicels 7-15 mm. Flowers: sepals persistent, connate ca. 1/2 of length, yellow, lanceolate, 1.6-2.6 × 0.8-1.2 mm, margins denticulate, glabrous; petals golden yellow, oblong to ovate, 10-13 × 2-4 mm; stamens yellow, 20-30 mm; anthers 1.9-2.6 mm; gynophore 15-25 mm in fruit; ovary 3-6 mm; style 0.5-0.8 mm. Capsules not inflated, 40-60 × 2-5 mm, striate. Seeds 15-30, gray to black, triangular (sharply angled), 3-4 × 2.5-3 mm, rugose.
Flowering summer. Dry sandy flats, desert scrub, roadsides; 300-1200 m; Ariz., Calif.; Mexico (Baja California).
Often treated as a variety of Peritoma lutea, P. jonesii grows at lower elevations, has a more southerly (though overlapping) range (T. H. Kearney and R. H. Peebles 1960), and differs in morphological features. Most notable are its larger, showier flowers and longer capsules.