Crocanthemum canadense |
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Canada frostweed, Canada rockrose or frostweed, crocanthème du Canada |
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Habit | Herbs. |
Stems | ascending to erect, usually red-tinged, 15–50(–65) cm, stellate-pubescent to glabrate. |
Leaves | cauline; petiole 1–3 mm; blade oblanceolate-elliptic to narrowly elliptic, tapered to base, 12–30(–38) × 4–7(–10) mm, apex acute, surfaces stellate-tomentose and with scattered simple hairs abaxially, ± lustrous, sparsely stellate-pubescent and with simple hairs adaxially, lateral veins raised abaxially. |
Inflorescences | terminal or subterminal, cymes; chasmogamous flowers 1–3 per cyme, cleistogamous 1–3 per glomerule, on lateral leafy branches 6–18 cm, flowering 1–3 months later than chasmogamous. |
Pedicels | (1.5–)4–10(–17) mm, with stellate and simple hairs; bracts absent. |
Chasmogamous | flowers: outer sepals narrowly lanceolate, 2–6 × 0.5–1 mm, inner sepals 5–9 × 3.5–5 mm, apex acute; petals obovate, 8–15 × 6–14 mm; capsules 5–8 × 4–7 mm, glabrous. |
Cleistogamous | flowers: outer sepals rudimentary, 0.2–0.5 × 0.2–0.4 mm, inner sepals obovate, 2.5–4 × 2.5–3.5 mm, apex acute; capsules 2.3–3.5 × 2.5–3.5 mm, glabrous. |
2n | = 20. |
Crocanthemum canadense |
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Phenology | Flowering late Mar–Jul(–Aug). |
Habitat | Sandy or rocky barrens, glades, sandhills, prairies, fields, roadsides, maritime grasslands and heathlands, interdunes, pine-oak woodlands, oak-hickory woodlands, rocky slopes |
Elevation | 0–700 m (0–2300 ft) |
Distribution |
AL; CT; DC; DE; GA; IA; IL; IN; KY; MA; MD; ME; MI; MN; MO; NC; NH; NJ; NY; OH; PA; RI; SC; TN; VA; VT; WI; WV; NS; ON; QC |
Discussion | Crocanthemum canadense and C. dumosum are distinguished from sympatric species by simple hairs among the stellate ones on leaf surfaces and by reddish colored stems. Until the twentieth century, C. canadense was treated much more broadly, to include C. bicknellii, C. dumosum, and C. propinquum; it differs from C. bicknellii and C. propinquum by having simple hairs on foliage (versus stellate only) and larger cleistogamous capsules. Its closest relative is 7. C. dumosum; see that treatment for identification aids. (Discussion copyrighted by Flora of North America; reprinted with permission.) |
Source | FNA vol. 6, p. 403. |
Parent taxa | Cistaceae > Crocanthemum |
Sibling taxa | |
Synonyms | Cistus canadensis, Helianthemum canadense, H. canadense var. sabulonum, Lechea major |
Name authority | (Linnaeus) Britton: in N. L. Britton and A. Brown, Ill. Fl. N. U.S. ed. 2, 2: 540. (1913) |
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