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tree mallow

island mallow, malva rosa

Habit Herbs, biennial or perennial, or subshrubs, 1–3 m, stellate-tomentose. Shrubs, 1–4 m, stellate-hairy to glabrate.
Stems

erect, base usually woody.

erect to decumbent, base woody.

Leaves

stipules deciduous, ovate, 4–5 × 2–3 mm, papery, apex acute to obtuse, sparsely stellate-hairy and ciliate;

petiole longer than blade;

blade rounded, shallowly and unequally 5–7(–9)-lobed (lobes obtuse), 5–20 × 5–20 cm, base cordate, margins crenate, apex obtuse to rounded, surfaces densely soft stellate-hairy especially abaxially.

stipules early-deciduous, lanceolate to ovate, 2–4 × 0.6–1.5 mm, minutely stellate-puberulent;

petiole as long as or longer than blade;

blade free filaments 1–2 mm;

anthers on distal 1/2;

style 6–10-branched (same number as locules), purplish;

stigmas 6–10 (same number as locules), purplish.

Inflorescences

axillary, flowers in fascicles.

Pedicels

jointed distally, 0.5–1 cm, not much longer in fruit;

involucellar bractlets connate in proximal 1/3, adnate to calyx, lobes broadly ovate to round, 8 × 5–6 mm, longer than calyx, margins entire, apex acute or obtuse, surfaces stellate-hairy.

Flowers

calyx 3–4 mm, not much enlarged in fruit, densely stellate-canescent;

petals rose to lavender with 5 darker veins, dark purple basally, 15–20 mm, length 4–5 times calyx, apex emarginate;

staminal column 8–10 mm, glabrous proximally, stellate-hairy distally;

anthers purplish;

style (6–)8(or 9)-branched;

stigmas (6–)8(or 9).

Seeds

dark brown, 3 mm.

dark brown, 4 mm, nearly as thick as long, notch slight.

Schizocarps

8–10 mm diam.;

mericarps (6–)8(or 9), 4–5 mm, margins sharp-angled, apical surface and sides ridged, surfaces glabrous or hairy.

12–16 mm diam.;

mericarps 6–10, 6–7 mm, apical face and margins sharp-edged, surfaces smooth to faintly ribbed, glabrous or puberulent on apical surface.

2n

= 36, 40, 42, 44.

= ca. 40.

Malva arborea

Malva assurgentiflora

Phenology Flowering Apr–May(–Sep). Flowering Feb–Jun and Sep–Oct, sporadically year-round.
Habitat Disturbed areas, coastal bluffs, dunes Coastal bluffs, disturbed areas
Elevation 0–200 m [0–700 ft] 0–400 m [0–1300 ft]
Distribution
map from FNA
CA; OR; Europe; Pacific Islands (New Zealand); Australia [Introduced in North America; introduced also in Mexico (Baja California), Africa (Libya), Atlantic Islands (Canary Islands)]
[WildflowerSearch map]
[BONAP county map]
map from FNA
CA [Introduced in Mexico, Central America (Guatemala), South America (Bolivia, Chile, Ecuador, Peru), Pacific Islands (New Zealand), Australia]
[WildflowerSearch map]
[BONAP county map]
Discussion

Malva arborea is infrequently cultivated as a garden ornamental. It is traditionally placed in Lavatera and has three prominent, spreading, rounded, earlike involucellar bractlets and inconspicuous sepals.

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

Malva assurgentiflora, traditionally placed in Lavatera, has long been cultivated as an ornamental or windbreak in California and is native only on the Channel Islands. It has become naturalized on the mainland as well as in Mexico and sparingly elsewhere. The shrubby habit, large flowers with dark-veined petals, and thick, hemispheric, fruits make it distinctive; it is our only native species of Malva. The petals are often recurved with age, and the corky mericarps float and are tolerant of salt water. Further study may indicate that there are two distinct subspecies, as suggested by R. N. Philbrick (1980).

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

Parent taxa Malvaceae > subfam. Malvoideae > Malva Malvaceae > subfam. Malvoideae > Malva
Sibling taxa
M. alcea, M. assurgentiflora, M. moschata, M. neglecta, M. nicaeensis, M. parviflora, M. pseudolavatera, M. pusilla, M. sylvestris, M. verticillata
M. alcea, M. arborea, M. moschata, M. neglecta, M. nicaeensis, M. parviflora, M. pseudolavatera, M. pusilla, M. sylvestris, M. verticillata
Synonyms Lavatera arborea Lavatera assurgentiflora, L. assurgentiflora subsp. glabra, Saviniona assurgentiflora, S. clementina, S. reticulata
Name authority (Linnaeus) Webb & Berthelot: Hist. Nat. Îles Canaries 3(2,1): 30. (1836) (Kellogg) M. F. Ray: Novon 8: 290. (1998)
Source FNA vol. 6, p. 288. Treatment author: Steven R. Hill. FNA vol. 6, p. 288. Treatment author: Steven R. Hill.
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