Hibiscus rosa-sinensis |
Hibiscus |
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Chinese hibiscus, shoe-black plant |
hibiscus, rose-mallow |
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Habit | Shrubs or trees, 1–3(–5) m. Stems: new growth finely and sparingly stellate- or simple-hairy. | Herbs, annual or perennial, subshrubs, shrubs, or trees, glabrous or hairy. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Stems | erect, Inflorescences axillary, sometimes adnate to subtending petiole (H. moscheutos), flowers solitary or clustered; involucel present, bractlets usually persistent, rarely deciduous (H. mutabilis), 6–16, rarely minute or absent (H. denudatus), distinct, undivided, 2-fid or appendaged (H. acetosella, H. aculeatus, H. furcellatus, H. radiatus). |
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Leaves | stipules linear to lanceolate, 8–16 mm; petiole usually to 1/3 blade, adaxial groove hairy with minute, ± sinuous hairs, sometimes villous; blade ovate, unlobed or only very rarely lobed, 5–12 × 3–8.5 cm, base rounded to cuneate, margins coarsely serrate in distal 2/3–3/4, apex acute to short-acuminate, surfaces glabrate, nectary present abaxially on midvein near base. |
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Inflorescences | solitary flowers, in axils of distal leaves. |
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Pedicels | jointed closer to flower, 4–9.5 cm, sparsely stellate-pilose or ± glabrous; involucellar bractlets 6–8, narrowly lanceolate to narrowly triangular, 0.3–2.2 cm, width varying in same flower, margins not ciliate, surface and margins puberulent or glabrate. |
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Flowers | showy, horizontal or declinate, sometimes double; calyx divided 1/2–3/4 length, narrowly campanulate, 2–3 cm, lobes triangular or narrowly so, apices acute to acuminate, often minutely, sparingly hairy, nectaries absent; corolla funnelform to rotate or petals slightly reflexed, petals usually red, sometimes pink, white, or yellow (or other colors in horticultural forms), usually darker at base, broadly to narrowly obovate, 6–10.5 × 4–6.5 cm, margins entire or crenate, often undulate, finely hairy abaxially mostly where exposed in bud; staminal column straight or moderately curved, usually red, often pink or white, 6.5–11.5 cm, bearing filaments in distal 1/2; free portion of filaments not secund, 3–9 mm, pollen yellow; styles red, pink, or white, 6–15 mm; stigmas usually reddish, sometimes golden yellow. |
usually lasting for a day; calyx persistent, sometimes accrescent, inflated or not, not spathaceous, primary veins usually ± straight, rarely zigzag (H. trionum, sometimes H. dasycalyx), lobes triangular to trullate, sometimes strongly 3-ribbed (H. acetosella, H. aculeatus, H. furcellatus, H. radiatus), sometimes with nectary on midrib; corolla radial or weakly bilaterally symmetric, narrowly funnelform to broadly campanulate or rotate or petals sometimes recurved (H. clypeatus), white, cream, yellow, orange, pink, red, lavender, purple, or blue, usually red, purple, or brown basally; staminal column included or exserted (H. coccineus, H. poeppigii, H. schizopetalus); ovary 5-carpellate; ovules 8–60 per carpel; styles 5-branched from or beyond orifice of staminal column; stigmas capitate to discoid or wedge-shaped (H. striatus). |
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Fruits | capsules, 5-valved, ovoid or spheroid, apex usually apiculate, acute, or acuminate, sometimes rounded or depressed or impressed, glabrous or hairy. |
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Capsules | seldom produced, brown, ovoid, 2.5–3 cm, apex rounded or beaked, glabrous. |
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Seeds | (rarely produced in cultivation), dark brown to black, reniform, 5 mm, minutely pubescent. |
to 60 per locule, reniform-ovoid, reniform-globose, or subglobose, sometimes angulate, sometimes laterally compressed or impressed, papillose or not, glabrous or hairy. |
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x | = 10, 11, [12,] 14, [15–17,] 18, 19, [20,] 26, [27,] and probably higher. |
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2n | = 36, 46, 54, 63, 68, 72, 77, 84, 90, 92, 96, 112, 132, 144, 147, 150, 160, 165, 168, 180, 225 (all cultivars). |
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Hibiscus rosa-sinensis |
Hibiscus |
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Phenology | Flowering year-round. | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Habitat | Disturbed sites | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Elevation | 0–50 m (0–200 ft) | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Distribution |
CA; FL [Introduced in North America; introduced also in Mexico, West Indies, Bermuda, Central America, South America, s Asia, Africa, Indian Ocean Islands, Pacific Islands, Australia] |
North America; Mexico; Central America; South America; West Indies; Eurasia; Africa; Indian Ocean Islands; Pacific Ocean Islands; Australia |
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Discussion | Hibiscus rosa-sinensis is widely cultivated in the Tropics and subtropics, often as a hedge plant; it naturalizes sparingly, probably throughout its cultivated range. It is not known to exist anywhere as a native occurrence; it has been thought to have originated in China (C. Linnaeus 1753), Africa (J. van Borssum Waalkes 1966; A. C. Smith 1979–1996, vol. 2), or the New World Tropics (L. van der Pijl 1937; G. F. Carter 1954; see also H. D. V. Prendergast 1982). As broadly circumscribed here, H. rosa-sinensis includes a wealth of hybrids and other selections and, as its range of chromosome numbers suggests, it has had a complicated history in cultivation (F. Singh and T. N. Khoshoo 1970), which probably includes hybridization with the African H. schizopetalus and the Hawaiian H. arnottianus A. Gray, H. kokio Hillebrand, and H. waimeae A. Heller (E. V. Wilcox and V. S. Holt 1913). It usually fails to set seed and is generally propagated by cuttings. (Discussion copyrighted by Flora of North America; reprinted with permission.) |
Species ca. 350 (21 in the flora). Taxonomy of Hibiscus is in flux. Molecular studies place members of some other genera in Hibiscus as traditionally circumscribed, indicating paraphyly (B. E. Pfeil and M. D. Crisp 2005). Neither of the two solutions to this problem—vastly expanding the circumscription of Hibiscus to include the nested genera, or breaking Hibiscus into smaller genera—has been attempted here. The 21 species of Hibiscus in the flora area are scattered among nine sections. The sections follows: sect. Hibiscus (species 1), sect. Bombicella de Candolle (species 2–6), sect. Furcaria de Candolle (species 7–10), sect. Lilibiscus Hochreutiner (species 11 and 12), sect. Muenchhusia (Heister ex Fabricius) O. J. Blanchard (species 13–17), sect. Venusti Ulbrich (species 18), sect. Striati O. J. Blanchard (species 19), sect. Trionum de Candolle (species 20), and sect. Clypeati O. J. Blanchard (species 21). Most Hibiscus species in the flora area are native; seven were introduced into North America either for horticultural purposes (H. acetosella, H. mutabilis, H. rosa-sinensis, H. schizopetalus, H. syriacus, and H. trionum) or as fiber crops (H. radiatus). Experimental crosses among some native species (H. coccineus, H. grandiflorus, H. laevis, and H. moscheutos) have been the basis of selections of hardy Hibiscus available in the horticultural trade. A popular cultivated form in the South is the result of an experimental cross involving a complex interspecific hybrid combining H. coccineus, H. laevis, and H. moscheutos as the staminate parent and H. mutabilis as the pistillate parent (H. F. Winters 1970). North American taxa in the speciose sect. Bombicella share a base chromosome number of × = 11 (chromosome numbers are unknown for Hibiscus coulteri); those in sect. Furcaria, × = 18; and those in sect. Muenchhusia, × = 19. Base numbers of the two sections represented in the flora area by one native species each are 10 and 26, and cannot be readily reconciled between themselves or with the others. The remaining four sections together include five species, all of which are non-natives and, except for H. trionum, have long histories in cultivation and multiple different chromosome numbers that are not easily evaluated. This overall chromosomal diversity supports the molecular evidence for a polyphyletic Hibiscus. Extensive experimental hybridization work in sect. Furcaria, and the study of chromosome pairing relationships in these hybrids, indicate that the native species Hibiscus aculeatus and H. furcellatus, both tetraploids, share the genomic makeup GGPP, while the introduced species H. acetosella and H. radiatus, also tetraploids, share AABB (F. D. Wilson 1994). A naturally occurring hybrid between Hibiscus coulteri and H. denudatus (Hibiscus ×sabei Weckesser) has been documented from western Texas (W. Weckesser 2011). Some desert species of Hibiscus sometimes produce cleistogamous flowers. Foliar nectaries are present abaxially near the base of the midvein in some species. Three species of Hibiscus are of doubtful status in the flora area. Hibiscus cannabinus Linnaeus and H. sabdariffa Linnaeus have both been cultivated in the southern states as fiber crops, and the latter also for its fleshy calyces, which are used to flavor beverages. It is doubtful that either has become established in the flora area. Hibiscus bifurcatus Cavanilles is widely distributed from the West Indies and Guatemala to South America; it was documented with two collections from Dade County in Florida by R. Woodbury in 1949 and 1950, but since Woodbury was involved at the time in establishing what later became the John C. Gifford Arboretum in Coral Gables south of Miami, there is a good chance that the source was a plant in cultivation. (Discussion copyrighted by Flora of North America; reprinted with permission.) |
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Key |
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Source | FNA vol. 6, p. 261. | FNA vol. 6, p. 252. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Parent taxa | Malvaceae > subfam. Malvoideae > Hibiscus | Malvaceae > subfam. Malvoideae | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
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Name authority | Linnaeus: Sp. Pl. 2: 694. (1753) | Linnaeus: Sp. Pl. 2: 693. (1753): Gen. Pl. ed. 5, 310. (1754) | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
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