Crocanthemum rosmarinifolium |
Crocanthemum greenei |
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rosemary frostweed |
island rush-rose |
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Habit | Herbs. | Subshrubs. |
Stems | ascending to erect, (13–)20–40(–51) cm, stellate-tomentose. |
erect, 15–30 cm, sparsely to densely stellate-pubescent, distally with dense, dark, glandular hairs 0.4–0.8 mm. |
Leaves | cauline and, sometimes, basal basal mat-forming; petiole 1–3 mm; blade obovate, 10–22 × 3–5 mm; cauline: petiole 1–4 mm; blade oblanceolate to narrowly lanceolate, 10–38(–48) × 2–5.5(–7.8) mm, margins revolute; surfaces stellate-tomentose abaxially, stellate-pubescent adaxially, without simple hairs; lateral veins obscure abaxially. |
cauline; petiole 0–2.5 mm; blade oblanceolate to linear-lanceolate, 7–25(–35) × 2–4(–7) mm, margins nonrevolute, surfaces stellate-pubescent, lateral veins obscure abaxially. |
Inflorescences | axillary and terminal, solitary flowers or glomerules; chasmogamous flowers solitary, at tips of branches, overtopping cleistogamous, cleistogamous 2–7 per glomerule, flowering 1–3 months later than chasmogamous. |
terminal, corymbose; chasmogamous flowers 3–25 per corymb, cleistogamous 0. |
Pedicels | 10–22 mm; bracts 3–7 × 0.5–1 mm. |
1–4(–6) mm, stellate-pubescent and densely glandular-hairy; bracts 3–10 × 0.5–1.5 mm. |
Chasmogamous | flowers: outer sepals linear, 1.2–2.5 × 0.2 mm, inner sepals 2.5–4.3 × 1.3–2 mm, apex acute; petals obovate, 4–6 × 3.5–5 mm; capsules 2–3 × 1.4–1.8 mm, glabrous. |
flowers: outer sepals lanceolate, 2.5–4 × 0.5–1 mm, inner sepals 4.5–8 × 3–4 mm, apex acuminate; calyx strigose (sometimes also short-stellate-hairy), hairs simple, 1–1.7 mm; petals obovate, 5–8 × 3–4 mm; capsules 4.3–6 × 3–3.5 mm, glabrous. |
Cleistogamous | flowers: outer sepals linear, 0.5–1 × 0.2 mm, inner sepals ovate, 1.5–1.8 × 1–1.5 mm, apex acute; capsules 1.3–1.7 × 1–1.3 mm, glabrous. |
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Crocanthemum rosmarinifolium |
Crocanthemum greenei |
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Phenology | Flowering May–Jul. | Flowering Apr–May. |
Habitat | Dry, sandy roadsides, openings in pine and pine-oak woodlands, disturbed soil of clearings and fields | Dry, rocky ridges |
Elevation | 0–200 m (0–700 ft) | 10–100 m (0–300 ft) |
Distribution |
AL; AR; FL; GA; LA; MS; NC; OK; SC; TX; West Indies (Dominican Republic) |
CA |
Discussion | Crocanthemum rosmarinifolium is easily distinguished from sympatric species by its slender leaves, relatively small petaliferous flowers, occasional basal leaves, and overall pale color. As noted by R. M. Harper over a century ago, it seems not to occupy natural habitats and is found primarily on roadsides. Populations in the Dominican Republic occur up to at least 2200 m. (Discussion copyrighted by Flora of North America; reprinted with permission.) |
Crocanthemum greenei has been documented from San Miguel, Santa Catalina, Santa Cruz, and Santa Rosa islands. According to the California Native Plant Society, it is extant on Santa Catalina, Santa Cruz, and Santa Rosa islands, totaling about 20 populations and listed federally as threatened. Threats are from non-native mammals and plants. The habit, dense, dark glandular hairs on stems and pedicels, and long, white hairs on the calyx distinguish C. greenei. (Discussion copyrighted by Flora of North America; reprinted with permission.) |
Source | FNA vol. 6, p. 407. | FNA vol. 6, p. 406. |
Parent taxa | Cistaceae > Crocanthemum | Cistaceae > Crocanthemum |
Sibling taxa | ||
Synonyms | Helianthemum rosmarinifolium, C. domingense, C. stenophyllum | Helianthemum greenei |
Name authority | (Pursh) Janchen: in H. G. A. Engler et al., Nat. Pflanzenfam. ed. 2, 21: 307. (1925) | (B. L. Robinson) Sorrie: Phytologia 93: 270. (2011) |
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