1. Alcea rosea
L. (hollyhock)
Althaea rosea (L.) Cav.
Pl. 450 c, d;
Map 2043
Plants biennial
or perennial herbs, variably pubescent throughout with smaller stellate hairs
and coarse simple hairs (these mostly in fascicles), somewhat roughened to the
touch. Stems 100–300 cm long, mostly erect, usually unbranched. Leaves
long-petiolate, the blades 2–10 cm long, broadly ovate to circular or
kidney-shaped in outline, at least the lower leaves shallowly 5- or 7-lobed,
the base rounded to shallowly cordate, pointed to more commonly rounded at the
tip, the margins shallowly scalloped or toothed. Stipules shed before leaf
maturity, 3–9 mm long, lanceolate. Flowers solitary or in small clusters in the
leaf axils, often also in a terminal spikelike raceme, the bractlets subtending
the calyx 6–9, conspicuous, 9–12 mm long, fused toward the base, the lobes
broadly triangular. Calyces 16–24 mm long, cup-shaped at fruiting, the sepals
fused in the basal 1/3–1/4, the lobes triangular. Petals 35–50 mm long, the
tips broadly rounded to truncate or shallowly notched, the margin otherwise
entire or nearly so, white to dark purplish black, often pink. Stamens
numerous, the staminal column 5-angled in cross-section, without a low crown of
teeth at the tip, the anthers yellow. Pistils with 18–40 locules, the carpels
arranged in a loose apically flattened ring. Styles fused most of their length,
each branch with a single linear stigmatic area along the inner side toward the
tip. Fruits schizocarps breaking into 18–40 mericarps. Mericarps 4–8 mm long,
wedge-shaped, tan to brown, beakless, the dorsal surface with a longitudinal
groove, kidney-shaped to nearly circular in profile, the lateral walls thin and
smooth but with a reticulate pattern of thickenings toward the dorsal margin,
which is angled into a narrow wing, the thin portion shattering irregularly at
maturity (the fruit also eventually breaking apart into individual mericarps),
1-seeded. Seeds 3–4 mm long, kidney-shaped, the dorsal portion densely and
minutely pubescent with mostly spreading fascicles of hairs, brown. 2n=42.
May–September.
Introduced,
uncommon and widely scattered in the state (native range unknown but presumably
southwestern Asia; widely and sporadically escaped from cultivation in the
U.S.). Roadsides, railroads, and open disturbed areas.
Hollyhocks are
widely cultivated as ornamentals in Missouri, but rarely become established
outside gardens. A large number of cultivars exist varying in plant height,
corolla colors, and leaf morphology, including some with doubled corollas, and
the few specimens of escaped plants reflect this variability. Some authors
continue to maintain Alcea as part of an expanded concept of the genus Althaea,
but Zohary (1963a, b) and D. A. Webb (1968), among others, have separated the
two groups based on differences in inflorescence and flower structure and size.