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rattlebox, showy crotalaria, showy rattlebox

Habit Herbs annual.

suffrutescent basally, erect, 50–150 cm, glabrous.



stipules ovate to ovate-lanceolate, not decurrent on stem, 4–7 mm;

blade obovate to elliptic, 50–150 mm, length 1.5–2.5 times width, surfaces glaucous, strigose abaxially, glabrous-punctate adaxially.


12–22-flowered, terminal, subterminal, or lateral, 10–50 cm;

bracts persistent, cordate-auriculate, 5–8 mm.


calyx broadly cylindrical, 10–15 mm, lobes triangular-lanceolate, glabrous;

corolla bright yellow, faintly red-lined, 17–25 mm.


30–45 × 10–20 mm, glabrous.


= 16.

Crotalaria spectabilis

Phenology Flowering (Jan–)Aug–Oct (year-round).
Habitat Grassy or fallow fields, roadsides, ditches, borrow pits, lake edges, disturbed areas.
Elevation 10–200 m. (0–700 ft.)
from FNA
AL; AR; FL; GA; IL; LA; MD; MO; MS; NC; SC; TN; TX; VA; Asia [Introduced in North America; introduced also in Mexico, West Indies, Central America, South America, Indian Ocean Islands (Reúnion), Pacific Islands]
[WildflowerSearch map]
[BONAP county map]

In Texas, Crotalaria spectabilis is known from Brazos, Cameron, Karnes, and Liberty counties.

(Discussion copyrighted by Flora of North America; reprinted with permission.)

Source FNA vol. 11.
Parent taxa Fabaceae > subfam. Faboideae > Crotalaria
Sibling taxa
C. avonensis, C. incana, C. juncea, C. lanceolata, C. ochroleuca, C. pallida, C. pumila, C. purshii, C. retusa, C. rotundifolia, C. sagittalis, C. trichotoma, C. verrucosa, C. virgulata
Synonyms C. retzii
Name authority Roth: Nov. Pl. Sp., 341. (1821)
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