Hibiscus denudatus


Bot. Voy. Sulphur, 7, plate 3. 1844.

Common names: Paleface rose-mallow
Treatment appears in FNA Volume 6. Treatment on page 257. Mentioned on page 252, 253, 254, 255, 258.

Subshrubs, to 0.8 m, herbage densely ± yellowish stellate-tomentose throughout. Stems: older twigs yellowish brown, glabrescent, line of fine hairs obscured by other pubescence or absent. Leaves: stipules narrowly triangular to subulate, 1–3 mm; petiole to 1/2 as long as blade, adaxial fine, curved hairs absent or obscured by other pubescence; blade oblong or broadly to narrowly ovate (often folded in pressed specimens), usually unlobed, rarely shallowly 3-angulate-lobate, mostly 1.2–3 × 1–2.5 cm, base cuneate to rounded or truncate, margins irregularly and coarsely dentate or dentate-crenate, apex broadly acute to truncate, surfaces stellate-tomentose, ± obscured nectary present abaxially on midvein near base. Inflorescences solitary flowers in axils of distal leaves. Pedicels obscurely joined below apex, 0.5–2 cm, equaling or exceeding subtending petioles; involucellar bractlets 7–10, often absent, narrowly triangular to subulate, to 0.6 cm, margins not ciliate. Flowers ascending to erect; calyx divided 2/3–4/5 length, funnelform, 0.7–1.6 cm, lobes narrowly triangular-ovate, apices acuminate, nectaries absent; corolla rotate, petals pale purple or pink to nearly white, with maroon spot or lines basally, asymmetrically obovate, 1.3–3 × 0.9–2 cm, margins ± entire, finely hairy abaxially where exposed in bud; staminal column straight, pink, 0.4–1.1 cm, bearing filaments throughout, free portion of filaments not secund, 1–3 mm; pollen dark orange; styles pale pink, 1.5–4 mm; stigmas pale pink to maroon. Capsules dull yellow-green with darker medial stripe on each valve, drying straw-colored, ovoid to subglobose, 0.6–1 cm, shorter than calyces, apex apiculate, glabrous or with minute hairs near apex and on sutures. Seeds dark brown, angulately reniform-ovoid, 2.2–3 mm, whitish, silky-hairy ± throughout, hairs 3–4 mm. 2n = 22 (Mexico: Durango).

Phenology: Flowering year-round.
Habitat: Desert, often rocky
Elevation: 30–1800 m


V6 463-distribution-map.jpg

Ariz., Calif., Nev., N.Mex., Tex., Mexico (Baja California, Baja California Sur, Chihuahua, Coahuila, Durango, Sonora).


Hibiscus denudatus has been recorded from Imperial, Riverside, San Bernardino, and San Diego counties in southern California; from southernmost Nevada (southern Clark County); from the southern half and near the Grand Canyon in Arizona; from southwestern New Mexico; and from the region west of the Pecos River in Texas.

As noted in the previous species, a naturally occurring hybrid between Hibiscus denudatus and H. coulteri (Hibiscus ×sabei Weckesser) has recently been documented from western Texas (W. Weckesser 2011).

Selected References


Lower Taxa

... more about "Hibiscus denudatus"
Orland J. Blanchard Jr. +
Bentham +
Paleface rose-mallow +
Ariz. +, Calif. +, Nev. +, N.Mex. +, Tex. +, Mexico (Baja California +, Baja California Sur +, Chihuahua +, Coahuila +, Durango +  and Sonora). +
30–1800 m +
Desert, often rocky +
Flowering year-round. +
Bot. Voy. Sulphur, +
Hibiscus denudatus +
Hibiscus +
species +