Perennial herb 1 - 2.5 m tall
Stem: erect, bushy, much branched, and with upper areas concealed by felt-like covering of forked or branched hairs.
Leaves: alternate, stalked, firm, toothed, hairy, large (10 - 20 cm long and broad), palmately five- to seven-lobed, and maple-like with triangular terminal lobe.
Flowers: several, on 1 cm long stalks, in loose spike-like clusters from upper leaf axils. The showy, pinkish, large (at least 5 cm wide), radially symmetric, delicately fragrant flowers have five flaring petals, and the sepals are immediately subtended by three, narrowly linear, persistent bractlets.
Sepals: five, but fused at base, then separating into five, 1 - 1.5 cm long, triangular to egg-shaped lobes. The calyx as a whole is densely hairy, and persists in fruit.
Petals: five, pink-purple or rose, 2.5 - 3 cm long, inversely triangular with narrowed base and flaring outward to broad tips. The edges of the petal bases are lined with long soft hairs.
Stamens: numerous, but filaments fused into a stout, at most 1.5 cm long tube with coarse, branched hairs at its base, and the anthers protruding near the top.
Pistil: enclosed by the stamen tube, with numerous superior carpels (ovule-bearing structures), styles coming up through center of stamen tube, and ending with exserted, round-tipped stigmas.
Fruit: a ring of many, thin-walled, two- to four-seeded, 0.8 - 1 cm tall, oblong to egg-shaped, round-tipped, thin segments (mericarps) enclosed by the persistent sepals and subsepal bractlets. Each mericarp has hairless sides with obscure branched veins toward the outer edge, but the outer side of each mericarp has a dense covering of long, erect, stiff, unbranched hairs. Mericarps open lengthwise to disperse finely hairy seeds.
Root system: of woody rhizomes.
Similar species: Iliamna remota is similar to our species of Hibiscus, and probably most likely confused with H. syriacus, but that species has woody, hairless, unbranched stems; at least ten subsepal bractlets; much larger flowers (8 - 12 cm wide) with anthers all along the sides of the stamen tube and an elongate style column branching into five stigmas; and the fruit is a capsule enclosed within the persistent sepals which enlarge in fruit. Some species of Malva may appear superficially similar, but they are smaller overall (plant height, leaves, flowers), and the fruit segments are about as tall as wide, more rounded from side view, thicker and wedge-like on end, harder, and only single-seeded. Some sources claim I. remota is the same species as the northwestern Pacific coast and Rocky Mountain species I. rivularis. Aside from the great geographic separation, this western species supposedly is not as bushy, the sepal lobes are shorter (only 3 - 5 mm), the petals are shorter (2 - 2.5 cm), the fruit are shorter (at most 0.8 cm), and the leaves tend to be a bit smaller (not over 15 cm long) and sometimes only three-lobed and possibly with less pointed teeth.
Flowering: July to August
Habitat and ecology: Localized, this plant is native to Langham Island at Altorf in the Kankakee River in Kankakee County, IL.
Occurence in the Chicago region: native
Notes: Most eastern United States floras consider I. remota to be a singular species native only to the Kankakee River in Illinois. Accordingly, this would make it one of the rarest native plants in North America. Reports of I. remota from a mountaintop in Virginia refer to another similar species, I. corei, or as originally published I. remota var. corei. That species was listed as Federally Endangered in 2005 by the U.S. Fish and Wildlife Service, but I. remota still remains listed only as a Species of Concern. Some sources (such as USDA) consider those two species to be the same taxon as the entirely western species I. rivularis. To our knowledge there is little information available to support the conclusion that all of these plants are the same native species. Clearly the three very disparate geographic distributions (Illinois, Virginia, western United States) should raise some questions. In the original publication and description for I. remota Greene (1906, p. 207) clearly states his belief that this species is not the same as the western species I. rivularis: "By the extreme distance intervening between the habitat of this local plant of eastern Illinois and that of its nearest congeners, which are of the Rocky Mountain region, any well travelled [sic] American botanist would know that this plant could not represent any Rocky Mountain species. The isolation of it is so complete that one does not see how any "authority" could readily have pronounced it to be referable to a Pacific coast mountain species, even if it had not its two or three good [distinguishing] characters." Until a treatment for the Malvaceae is complete for the Flora of North America Project, we will continue to recognize I. remota as a distinct taxon.
Author: The Field Museum
Stellate-hairy perennial 1-2. 5 m; lvs 1-2 dm long and wide, 5-7-lobed; pedicels 1 cm; cal-lobes triangular-ovate, 10-15 mm; pet pink-purple, 2.5-3 cm; mature carpels oblong, 8-10 mm, the thin sides glabrous, reticulate-veined near the dorsal margin; seeds finely hairy. On an island in the Kankakee R., Ill. (the original station), and near the summit of Peters Mt., Va.; local along railroads in Ind. and Va. June, July. (Sphaeralcea r.; Phymosia r.; Iliamna corei Sherff, the Va. plant)
Gleason, Henry A. & Cronquist, Arthur J. 1991. Manual of vascular plants of northeastern United States and adjacent Canada. lxxv + 910 pp.
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