Sp. Pl. 2: 687. 1753.
Gen. Pl. ed. 5, 308. 1754.
Herbs, annual, biennial, or perennial, subshrubs, or shrubs, glabrous or hairy, hairs stellate or simple. Stems erect, ascending, or trailing. Leaves: stipules persistent or deciduous, linear, lanceolate, triangular, or ovate to ± falcate; blade orbiculate or reniform, unlobed or palmately 3–7(–9)-lobed or divided, base cordate to truncate, margins crenate to dentate. Inflorescences usually axillary, flowers usually in fascicles, sometimes solitary, sometimes terminal racemes; involucel present, bractlets persistent, 3, distinct or basally connate (or recurved pedicel), not inflated, oblate-discoid, usually depressed in center, around broad axis, without persistent swollen style base, ± indurate, glabrous or hairy; mericarps 6–15(–20), drying tan or brown, 1-celled, wedge-shaped (triangular in cross section), oblong to reniform, beak or cusp absent, sides thin and papery or thicker, margins usually edged, apex rounded, indehiscent. Seeds 1 per mericarp, adherent to mericarp wall, usually not readily separated from it, reniform-rounded, notched, glabrous. x = 21.
North America, Mexico, Eurasia, n Africa (especially Mediterranean region), introduced nearly worldwide.
Species 30–40 (11 in the flora).
Some species of Malva are weedy; five or six in the flora area generally occur in cultivation as ornamentals or as vegetables and occasionally escape. Some species previously treated within Lavatera (see M. F. Ray 1995, 1998) are here included in Malva based upon molecular evidence. Traditionally, Lavatera and Malva were separated by the presence of partially connate relatively wide involucellar bractlets in the former and distinct generally narrow bractlets in the latter. The annual species of Althaea (sect. Hirsutae Iljin ex Olyanitskaya & Tzvelev) may also belong within Malva, but have been kept separate here. Nomenclature in Althaea, Lavatera, and Malva is still in flux and a satisfactory classification is not yet available. Intergeneric hybrids among some species of all three genera suggest a close relationship.
|1||Shrubs, 1–4 m; petals 25–45 mm; calyces 12–15 mm; mericarps 6–10.||Malva assurgentiflora|
|1||Herbs or subshrubs, 0.2–3 m; petals 3–35(–45) mm (if subshrubs, petals to 20 mm); calyces 3–10(–15) mm; mericarps 6–15(–20)||> 2|
|2||Distal leaf blades deeply (3–)5–7-lobed; petals 20–35 mm||> 3|
|2||Distal leaf blades unlobed or shallowly lobed; petals 3–30(–45) mm||> 4|
|3||Hairs stellate-canescent; involucellar bractlets ovate or ovate-deltate to obovate; mericarps 18–20, glabrous or sparsely hairy.||Malva alcea|
|3||Hairs usually simple, sometimes stellate; involucellar bractlets linear to narrowly oblanceolate or elliptic; mericarps 11–15, densely hirsute apically.||Malva moschata|
|4||Petals (12–)16–30(–45) mm, length 2 1/2–3(–4) times calyx; involucellar bractlets distinct, sometimes adnate to calyx in basal 1 mm.||Malva sylvestris|
|4||Petals 3–15(–20) mm, length 1–2(–5) times calyx; involucellar bractlets distinct or partly connate and/or adnate to calyx (if petals longer than 14 mm, involucellar bractlets connate)||> 5|
|5||Involucellar bractlets connate in proximal 1/3–1/2, adnate to calyx, ovate-deltate, ovate, or round; petals 10–20 mm; stems usually erect, rarely prostrate, 1–3 m||> 6|
|5||Involucellar bractlets distinct, basally adnate to calyx (in M. nicaeensis) or not, filiform, linear, lanceolate, oblong-lanceolate, ovate, or obovate; petals 3–15 mm; stems erect or ascending to decumbent, procumbent, prostrate, or trailing, 0.2–0.8(–2.5) m||> 7|
|6||Involucel longer than calyx; leaf blade surfaces densely soft-stellate-hairy; petals rose to lavender with 5 darker veins; stem base usually woody.||Malva arborea|
|6||Involucel shorter than calyx; leaf blade surfaces sparsely stellate-hairy; petals pale pink to white, usually with 3 darker veins; stem base not woody.||Malva pseudolavatera|
|7||Involucellar bractlets basally adnate to calyx, broadly lanceolate to ovate or obovate; petals drying bluish, usually with darker veins.||Malva nicaeensis|
|7||Involucellar bractlets not adnate to calyx, filiform, linear, lanceolate, or oblong-lanceolate; petals drying pinkish or whitish, or faded, veins not much darker||> 8|
|8||Involucellar bractlets filiform to linear; calyces accrescent, lobes spreading outward exposing mericarps; petals 3–4.5(–5) mm, white to pale lilac; mericarp margins narrowly winged, toothed.||Malva parviflora|
|8||Involucellar bractlets linear, oblanceolate, or lanceolate; calyces not accrescent, or, if so, lobes usually enclosing mericarps; petals (3–)5–13 mm, pale lilac, pink, pinkish, purplish, to nearly white or whitish; mericarp margins not winged, sometimes toothed||> 9|
|9||Stems erect; plants 0.5–2.5 m; leaf blades 3–10(–25) cm; pedicels stout and rigid in fruit.||Malva verticillata|
|9||Stems prostrate or trailing to ascending; plants usually 0.2–0.6 m; leaf blades 1–3.5(–6) cm; pedicels slender and flexible in fruit||> 10|
|10||Petals 6–13 mm, length 2 times calyx; mericarps hairy, smooth to slightly roughened or reticulate.||Malva neglecta|
|10||Petals 3–6 mm, length subequal to or slightly exceeding calyx; mericarps hairy or glabrate, strongly rugose-reticulate.||Malva pusilla|