Drosera |
Drosera brevifolia |
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catch-fly, dew-threads, droséra, rossolis, sundew |
dwarf sundew, shortleaf sundew |
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Habit | Plants annual or perennial [rarely subshrubs], deciduous, stems 1–2 cm (except also caulescent stems to 8(–20) cm in D. intermedia), usually forming over-wintering buds (hibernaculae). | Plants not forming winter hibernaculae, rosettes to 2 (–3.5) cm diam.; stem base not bulbous-cormose. | ||||||||||||||||||||||||||||
Leaves | prostrate; stipules absent or reduced to 1 or 2 minute hairs; petiole often not differentiated from blade, dilated distally, 0.5–1 cm, glabrous; blade cuneate, 0.4–1 cm × 5–12 mm, usually longer than petiole. |
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Inflorescences | 1–8-flowered; scapes (1–)4–9 cm, stipitate-glandular. |
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Pedicels | stipitate-glandular. |
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Flowers | 15 mm diam.; sepals distinct, oblong-ovate, 2.5–3.5 × 1.5–2.5 mm, stipitate-glandular; petals white to rose-pink, obovate, 4–8 × 2–3 mm. |
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Capsules | obovoid, splitting between placentae. |
3 mm. |
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Seeds | 20–70, minute. |
black, obovoid or oblong, 0.3–0.5 mm, base caudate, crateriform, pits in 10–12 rows. |
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On | both surfaces in strong sunlight, greener in shade (except D. tracyi, which lacks red pigment even in full sun), unlobed, suborbiculate, orbiculate, spatulate, or obovate, or cuneate to linear pink, or rose to pinkish lavender; stamens 5, usually connate basally; gynoecium 3-carpellate; styles 3, deeply bifid; stigma capitate. |
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x | = 10. |
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2n | = 20. |
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Drosera |
Drosera brevifolia |
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Phenology | Flowering Apr–May(–Dec). | |||||||||||||||||||||||||||||
Habitat | Moist sandy-peaty pinelands and roadsides | |||||||||||||||||||||||||||||
Elevation | 0–300 m (0–1000 ft) | |||||||||||||||||||||||||||||
Distribution |
Nearly worldwide |
AL; AR; FL; GA; KS; KY; LA; MS; NC; OK; SC; TN; TX; VA; Mexico; Central America; West Indies (Cuba); South America (Brazil)
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Discussion | Species ca. 170 (8 in the flora). Species of Drosera are concentrated in Latin America, South Africa, Madagascar, Australia, and New Zealand. Droseras, like all carnivorous plants, have leaves that attract, catch, digest, and absorb nutrients from small, mostly arthropod prey. They are characterized by gland-tipped multicelled hairs that move in response to stimuli and that catch and appress prey to the leaf blade, where sessile glands secrete enzymes that dissolve the soft tissues. The released nutrients enhance growth by supplementing those available from the poor soils where they grow. All species of Drosera are capable of moving their trichomes in response to contact with digestible prey. According to C. (1875), this movement can be induced by the mere touch of a part of a small insect with a single trichome. Besides having trichome movement, some species are able to curl their leaf blades to various degrees in order to maximize contact with prey. Some species of Drosera may act as annuals, especially if the habitats dry out. The plants can be locally abundant. In most species, the flowers open only in the mornings on sunny days, or not at all on overcast days, and fruits may form from self-pollination. Some species, notably D. intermedia, may exhibit vegetative proliferation, portions of the flowers developing into leaves or plantlets. Some species form over-wintering buds called hibernaculae, requiring a cold period to break dormancy. Some species of Drosera are reportedly utilized in herbal medicines to produce cough preparations and treat lung and skin ailments. F. E. Wynne (1944) showed that seeds of North American Drosera are diagnostic for each species. The following key is adapted from various sources, and the species are presented in alphabetic order. Natural hybrids are rare in Drosera, and usually are sterile. (Discussion copyrighted by Flora of North America; reprinted with permission.) |
Drosera brevifolia is the smallest and perhaps the most widespread species of the genus in the Southeast. It may be rare or local throughout its range, and may act as an annual, especially if the habitat dries out. The flowers are large for the size of the plant, and the stipitate-glandular scapes, pedicels, and sepals are quite distinctive. The species is easy to grow 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. 420. | FNA vol. 6, p. 422. | ||||||||||||||||||||||||||||
Parent taxa | Droseraceae | Droseraceae > Drosera | ||||||||||||||||||||||||||||
Sibling taxa | ||||||||||||||||||||||||||||||
Subordinate taxa | ||||||||||||||||||||||||||||||
Synonyms | D. annua, D. leucantha | |||||||||||||||||||||||||||||
Name authority | Linnaeus: Sp. Pl. 1: 281. (1753): Gen. Pl. ed. 5, 136. (1754) | Pursh: Fl. Amer. Sept. 1: 211. (1813) | ||||||||||||||||||||||||||||
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