Physocarpus malvaceus

(Greene) Kuntze

Revis. Gen. Pl. 1: 219. 1891.

Common names: Mallow-leaved or mallow nine-bark
Endemic
Basionym: Neillia malvacea Greene Pittonia 2: 30. 1889
Synonyms: Opulaster pauciflorus (Torrey & A. Gray) A. Heller Physocarpus pauciflorus (Torrey & A. Gray) Piper
Treatment appears in FNA Volume 9. Treatment on page 349. Mentioned on page 348, 350.

Shrubs, 20 dm. Stems spreading, brown becoming grayish black, glabrous or finely stellate-hairy. Leaves: stipules oblong to elliptic or obovate, 6 × 2.5 mm, base broad, apex rounded and erose to apiculate or acute; petiole 1–2.5(–3) cm; blade broadly ovate to orbiculate, 2–6 × 2.5–6 cm, sometimes wider than long, base truncate to slightly cordate, 3- or 5-lobed, clefts between lobes may be shallow to deep, margins doubly crenate to doubly serrate, apex rounded, obtuse, or acute, surfaces glabrous or sparsely stellate-hairy (more so on abaxial veins). Inflorescences 15–20-flowered, fairly dense, hemispheric racemes, 2.5–4 cm diam.; bracts narrowly obovate to spatulate, 4.5 mm, apex erose or acute. Pedicels 8–15 mm, densely stellate-hairy. Flowers 5–8 mm diam.; hypanthium campanulate, 1.5–2 mm, densely stellate-hairy; sepals triangular to ovate, 2–3 mm, apex gland-tipped, surfaces densely stellate-hairy; petals white, broadly elliptic to obovate or orbiculate, 4.5 × 4.5 mm; stamens ca. 30, equal to or slightly exceeding petals; carpels 2(3), connate at least 1/2 their lengths, densely stellate-hairy. Follicles 2(3), ovoid, flattened, 2.5 mm (lengths not exceeding sepals), keeled apically, densely stellate-hairy, hairs white; styles 2.5–3 mm. Seeds 1 or 2, pyriform, 1.5 mm.


Phenology: Flowering May–Jul; fruiting Aug.
Habitat: Rocky canyon slopes and cliffs, open grassy slopes, dry open forests among Pinus, Juniperus, Pseudotsuga, Picea, and Populus
Elevation: 500–2800 m

Distribution

V9 575-distribution-map.jpg

Alta., B.C., Colo., Idaho, Mont., Nev., Oreg., Utah, Wash., Wyo.

Discussion

Physocarpus malvaceus deserves to be more widely cultivated.

Selected References

None.

Lower Taxa

None.
... more about "Physocarpus malvaceus"
Crinan Alexander +
(Greene) Kuntze +
Neillia malvacea +
Mallow-leaved or mallow nine-bark +
Alta. +, B.C. +, Colo. +, Idaho +, Mont. +, Nev. +, Oreg. +, Utah +, Wash. +  and Wyo. +
500–2800 m +
Rocky canyon slopes and cliffs, open grassy slopes, dry open forests among Pinus, Juniperus, Pseudotsuga, Picea, and Populus +
Flowering May–Jul +  and fruiting Aug. +
Revis. Gen. Pl. +
Opulaster pauciflorus +  and Physocarpus pauciflorus +
Physocarpus malvaceus +
Physocarpus +
species +