Penstemon venustus
Edwards’s Bot. Reg. 16: plate 1309. 1830.
Subshrubs. Stems ascending to erect, 18–80 cm, glabrous or retrorsely hairy, hairs pointed, not glaucous. Leaves cauline, opposite, glabrous, sometimes glaucous; cauline 7–15 pairs, short-petiolate or sessile, (20–)40–100(–120) × (7–)10–30(–38) mm, blade ovate to lanceolate, base tapered to truncate, margins subentire or serrate, apex acute. Thyrses interrupted, ± secund, (2–)7–40 cm, axis glabrous or retrorsely hairy, verticillasters (3–)5–14, cymes 2–7-flowered, 2 per node; proximal bracts lanceolate, (6–)23–70(–115) × (1–)4–28(–35) mm; peduncles and pedicels ascending to erect, glabrous or retrorsely hairy. Flowers: calyx lobes ovate to obovate or lanceolate, 2.5–6 × 1.3–1.8 mm, glabrous except for margins sometimes ciliate; corolla lavender to purple or violet, with reddish purple nectar guides, weakly ventricose, 24–38 mm, glabrous externally except lobe margins densely white-ciliate, glabrous internally, tube 7–9 mm, throat gradually inflated, 9–10 mm diam., rounded abaxially; stamens: longer pair reaching orifice or exserted, filaments white-lanate distally, rarely glabrous, pollen sacs parallel, 1.6–2.1 mm, distal 1/2–2/3 indehiscent, sides hispidulous, hairs white, to 0.2 mm near point of attachment of connective, sutures denticulate, teeth to 0.2 mm; staminode 16–19 mm, reaching orifice or barely exserted, 0.4–0.5 mm diam., distal 2–5 mm sparsely to moderately lanate, hairs white, to 2 mm; style 18–25 mm. Capsules 6–9 × 4–5 mm. 2n = 64.
Phenology: Flowering (May–)Jun–Sep.
Habitat: Rock outcrops, rocky and talus slopes, especially on basalt, shrublands, forest clearings.
Elevation: 300–2700 m.
Distribution
Calif., Idaho, Oreg., Utah, Wash.
Discussion
Penstemon venustus is known from the Snake River Plateau in west-central Idaho, northeastern Oregon, and southeastern Washington and is naturalized in Lassen County, California. E. C. Neese and N. D. Atwood (2003) reported P. venustus, apparently introduced, from Duchesne County, Utah. E. Heitz (1927) reported a chromosome number of 2n = 14–16 for P. venustus; that count conflicts with all other reports for P. venustus.
Selected References
None.