Flora of North America species comparison

The green links below add additional plants to the comparison table. Blue links lead to other Web sites.
enable glossary links

Crocanthemum scoparium

Crocanthemum greenei

Bisbee Peak rushrose, broom rushrose, peak rockrose, peak rush-rose

island rush-rose
Habit Subshrubs. Subshrubs.
Stems

spreading to erect-fastigiate, 10–45 cm, usually sparsely stellate-pubescent to glabrate, sometimes densely lanate.

erect, 15–30 cm, sparsely to densely stellate-pubescent, distally with dense, dark, glandular hairs 0.4–0.8 mm.
Leaves

cauline, tending to be deciduous in summer;

petiole 0–2 mm;

blade linear, 5–11 × 0.5–2(–3.5) mm, surfaces stellate-pubescent to glabrate abaxially, sparsely stellate-pubescent to glabrate adaxially, 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

terminal, panicles or racemes; chasmogamous flowers 1–18 per panicle or raceme, cleistogamous 0.

terminal, corymbose; chasmogamous flowers 3–25 per corymb, cleistogamous 0.
Pedicels

2–6 mm, sparsely or not glandular-hairy;

bracts 2–4 × 0.3–0.5 mm.

1–4(–6) mm, stellate-pubescent and densely glandular-hairy;

bracts 3–10 × 0.5–1.5 mm.
Chasmogamous

flowers: outer sepals linear, 1.5–3.5 × 0.3 mm, inner sepals 3.5–5(–7.5) × 2–3 mm, apex acute to acuminate;

calyx stellate-pubescent, hairs to 1 mm;

petals obovate, 3–6 × 3–5 mm;

capsules 2.8–3.8 × 2–2.5 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.

Crocanthemum scoparium

Crocanthemum greenei
Phenology Flowering Apr–May.
Habitat Dry, rocky ridges
Elevation 10–100 m (0–300 ft)
Distribution
from FNA
CA; nw Mexico
[WildflowerSearch map]
[BONAP county map]
from FNA
CA
[BONAP county map]
Discussion

Varieties 2 (2 in the flora).

Even with the recognition of Crocanthemum aldersonii and C. suffrutescens as separate species, morphological diversity within C. scoparium still remains considerable. The two varieties here recognized show differences in habit, average plant height, number of flowers, and distribution. Another variant occurs sporadically along the coast and on Santa Cruz Island, from Monterey to San Diego counties; vegetative parts (at least distal branches, pedicels, and sepals) are covered with white, lanate hairs. This variant has never been formally named. Another form from coastal Mendocino County was called “Helianthemum mendocinensis” by Alice Eastwood on a specimen (H. E. Brown 785, JEPS); the name was never published. These plants have densely stellate-pubescent stems and exceptionally elongate sepal tips.

(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.)
Key
1. Stems mostly 10–30 cm, divaricate and spreading or curved proximally and erect distally; mostly near-coastal.
var. scoparium
1. Stems usually 30–45 cm, usually erect-fastigiate, sometimes curved proximally and erect distally; mostly inland.
var. vulgare
Source FNA vol. 6, p. 407. FNA vol. 6, p. 406.
Parent taxa Cistaceae > Crocanthemum Cistaceae > Crocanthemum
Sibling taxa
C. aldersonii, C. arenicola, C. bicknellii, C. canadense, C. carolinianum, C. corymbosum, C. dumosum, C. georgianum, C. glomeratum, C. greenei, C. nashii, C. propinquum, C. rosmarinifolium, C. suffrutescens
C. aldersonii, C. arenicola, C. bicknellii, C. canadense, C. carolinianum, C. corymbosum, C. dumosum, C. georgianum, C. glomeratum, C. nashii, C. propinquum, C. rosmarinifolium, C. scoparium, C. suffrutescens
Subordinate taxa
C. scoparium var. scoparium, C. scoparium var. vulgare
Synonyms Helianthemum scoparium Helianthemum greenei
Name authority (Nuttall) Millspaugh: Publ. Field Mus. Nat. Hist., Bot. Ser. 5: 175. (1923) (B. L. Robinson) Sorrie: Phytologia 93: 270. (2011)
Web links 
Unless otherwise noted, all data comes from the online version of the Flora of North America, who have made most of their content available via a Creative Commons license (CC BY 4.0).



Type/paste one or more Latin names into the boxes above; matching taxa will show up below the box as you type. You can use the up/down arrow keys to move through the list.

(If the plant you're looking for doesn't show up in the auto-complete list, that means it either isn't described in Flora of North America yet, or it's listed under a synonym. And please note that Flora of North America is still missing several plant families, including Fabaceae, Apiaceae, Boraginaceae, and Polemoniaceae.)

Choose a data source: Flora of North America

The species comparison tool is brought to you by:
Northwest Wildflowers