13. Epilobium canum (Greene) P. H. Raven, Ann. Missouri Bot. Gard. 63: 335. 1977.
Zauschneria cana Greene, Pittonia 1: 28. 1887
Herbs suffruticose or not, with basal shoots from ± woody caudex, often decussate scales at base. Stems erect to ascending, often clumped but not matted, green or gray-green, terete, 10–110(–120) cm, usually well-branched throughout, sometimes simple, strigillose and/or long-villous, usually mixed glandular puberulent distally, rarely glabrate. Leaves ± densely spaced, alternate and often fasciculate distally, subsessile, blade grayish green or green to silvery-canescent, usually narrowly linear to lanceolate or elliptic to ovate, rarely orbiculate, 0.6–5(–6) × 0.1–2.5 cm, base cuneate to attenuate, margins subentire to sharply toothed, 3–15 teeth per side, veins inconspicuous or prominent, 3–7 per side, apex acute, sometimes with caducous dark mucro, surfaces usually ± densely strigillose, sometimes mixed villous and/or glandular puberulent, rarely glabrate; bracts much smaller and narrower. Inflorescences erect spikes or racemes, loose to congested, often branched, glandular puberulent and sometimes mixed strigillose or villous. Flowers: buds 11–18 × 4–6 mm, subsessile or pedicels 1–2 mm; floral tube same color as petals, 16–32 × 5–8 mm, base slightly bulbous, ring of 8 irregular scales at base of filaments 4–6.5 mm from base inside; sepals same color as petals, 7–15 × 3.5–5 mm, abaxial surface densely pubescent; petals usually orange-red, very rarely white, obcordate, 8–17 × 5–9.5 mm, apical notch 2–3 mm; filaments light orange-red to white, those of longer stamens 12.5–32 mm, those of shorter ones 10–25 mm; anthers 2.7–4 × 0.8–1.2 mm, apiculate; ovary 8–15 mm, glandular puberulent, often mixed villous; style light orange-red, 42–65 mm, glabrous, stigma 4-lobed, 1–1.4 × 2.4–3 mm, exserted 8–15 mm beyond anthers. Capsules straight or ± curved-ascending, 15–35 mm, sometimes beaked, surfaces glandular puberulent and strigillose; subsessile or pedicel 0–3 mm. Seeds broadly to narrowly obovoid, with constriction 0.6–0.8 mm from micropylar end, 1.5–2.6 × 0.9–1.3 mm, chalazal collar inconspicuous, light brown, surface low papillose; coma easily detached, dingy white, 5.5–7 mm.
Subspecies 3 (3 in the flora): sw United States, nw Mexico.
This treatment recognizes three self-compatible but highly outcrossing subspecies marked by distinct but sometimes intergrading morphology and overlapping geographical ranges. R. N. Bowman and P. C. Hoch (1979) agreed with the treatment of Epilobium canum subsp. Garrettii (n = 15) and subsp. Latifolium (n = 30) by P. H. Raven (1976), but considering the complex intergrading patterns of variation involving the rest of this species, they combined the two remaining tetraploid subspecies recognized by Raven (subspp. Angustifolium and mexicanum) with the remaining diploid subspecies into a single polyploid subsp. Canum.