Crocanthemum rosmarinifolium

(Pursh) Janchen in H. G. A. Engler et al.

in H. G. A. Engler et al., Nat. Pflanzenfam. ed. 2, 21: 307. 1925.

Common names: Rosemary frostweed
Basionym: Helianthemum rosmarinifolium Pursh Fl. Amer. Sept. 2: 364. 1813
Synonyms: Crocanthemum domingense (Urban) Janchen C. stenophyllum (Urban) Janchen
Treatment appears in FNA Volume 6. Treatment on page 407. Mentioned on page 401.

Herbs. Stems ascending to erect, (13–) 20–40 (–51) cm, stellate-tomentose. 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. 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. Pedicels 10–22 mm; bracts 3–7 × 0.5–1 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. 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.


Phenology: Flowering May–Jul.
Habitat: Dry, sandy roadsides, openings in pine and pine-oak woodlands, disturbed soil of clearings and fields
Elevation: 0–200 m

Distribution

V6 770-distribution-map.jpg

Ala., Ark., Fla., Ga., La., Miss., N.C., Okla., S.C., Tex., West Indies (Dominican Republic)

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.

Selected References

None.

Lower Taxa

None.
Bruce A. Sorrie +
(Pursh) Janchen in H. G. A. Engler et al. +
Helianthemum rosmarinifolium +
3.8 cm38 mm <br />0.038 m <br /> (4.8 cm48 mm <br />0.048 m <br />) +
0.55 cm5.5 mm <br />0.0055 m <br /> (0.78 cm7.8 mm <br />0.0078 m <br />) +
1 cm10 mm <br />0.01 m <br /> (3.8 cm38 mm <br />0.038 m <br />) +
oblanceolate +  and narrowly lanceolate +
0.2 cm2 mm <br />0.002 m <br /> (0.55 cm5.5 mm <br />0.0055 m <br />) +
0.3 cm3 mm <br />0.003 m <br /> (0.7 cm7 mm <br />0.007 m <br />) +
0.05 cm0.5 mm <br />5.0e-4 m <br /> (0.1 cm1 mm <br />0.001 m <br />) +
0.13 cm1.3 mm <br />0.0013 m <br /> (0.17 cm1.7 mm <br />0.0017 m <br />) +
0.1 cm1 mm <br />0.001 m <br /> (0.13 cm1.3 mm <br />0.0013 m <br />) +
Rosemary frostweed +
Ala. +, Ark. +, Fla. +, Ga. +, La. +, Miss. +, N.C. +, Okla. +, S.C. +, Tex. +  and West Indies (Dominican Republic) +
0–200 m +
connate +  and distinct +
later than chasmogamous +
cleistogamous +  and chasmogamous +
loculicidal +
Dry, sandy roadsides, openings in pine and pine-oak woodlands, disturbed soil of clearings and fields +
umbellate +, thyrsiform +  and cymose +
racemose +, paniculate +  and corymbose +
0.15 cm1.5 mm <br />0.0015 m <br /> (0.18 cm1.8 mm <br />0.0018 m <br />) +
0.1 cm1 mm <br />0.001 m <br /> (0.15 cm1.5 mm <br />0.0015 m <br />) +
stipulate +  and estipulate +
whorled +, opposite +  and alternate +
mat-forming +
basal +  and cauline +
undulate +  and revolute +
0.05 cm0.5 mm <br />5.0e-4 m <br /> (0.1 cm1 mm <br />0.001 m <br />) +
0.2 cm2 mm <br />0.002 m <br /> (?) +
6-12-carpellate +, 5-carpellate +, 3-carpellate +  and 2-carpellate +
crassinucellate +  and bitegmic +
orthotropous +
1 cm10 mm <br />0.01 m <br /> (2.2 cm22 mm <br />0.022 m <br />) +
crumpled +  and imbricate +
yellow +, white +, red +, purple +, pink +, dark red +  and green +
distinct +
obovate +
0.35 cm3.5 mm <br />0.0035 m <br /> (0.5 cm5 mm <br />0.005 m <br />) +
0.1 cm1 mm <br />0.001 m <br /> (0.4 cm4 mm <br />0.004 m <br />) +
Flowering May–Jul. +
in H. G. A. Engler et al., Nat. Pflanzenfam. ed. +
persistent +
40 cm400 mm <br />0.4 m <br /> (51 cm510 mm <br />0.51 m <br />) +
not dimorphic +
ascending +  and erect +
stellate-tomentose +
20 cm200 mm <br />0.2 m <br /> (40 cm400 mm <br />0.4 m <br />) +
3 +  and 1 +
sessile +  and petiolate +
stellate-pubescent +  and stellate-tomentose +
Crocanthemum domingense +  and C. stenophyllum +
Crocanthemum rosmarinifolium +
Crocanthemum +
species +