Sundew
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Drosera | ||||||||||||
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Missing image Drosera_aliciae.jpg Drosera aliciae | ||||||||||||
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Sundews are members of the genus Drosera, consisting of about 150 species of carnivorous plants. Examples of the sundews can be found on every continent but Antarctica; they are especially abundant in South Africa, Australia and South America. Some, such as the Pink Sundew, D. capillaris, and the Dwarf Sundew, D. brevifolia, are found on the eastern and Gulf coasts of North America. They can be found in most soil conditions, in acidic, sandy, stony, and boggy places.
The leaves of these plants have tentacles with drops of a sticky substance called mucilage at the ends; insects get stuck in this substance and become entangled. The substance then digests the helpless insect. In all members of the genus, the tentacles on the leaf bend toward the captured insect by thigmotropism; in most, the leaf-blade is also capable of rapid growth. In the Cape sundew (D. capensis), which has long, narrow leaves, the leaf usually folds over the prey item completely. The movement of the tentacles is particularly fast in some species, notably D. burmannii.
The morphology of sundews is extremely variable. Although all are herbs, they range in size from the Australian pygmy sundews such as D. pygmaea, the leaves of which are usually about 5 mm long, to the king sundew, D. regia and fork-leaf sundews (D. binata) which may have leaves 60 cm long. Most sundews forms small, tight rosettes (as seen in D. aliciae, the Alice sundew), or bear their leaves on short stems (as seen in D. capensis, the Cape sundew); however, the tuberous rainbow sundews, such as D. peltata form long wiry stems, which in D. gigantea (the giant sundew) may reach 1 m in height. Some of the Queensland sundews, such as D. schizandra, appear to be in the evolutionary process of loosing their adaptation to carnivory: their tentacles are much reduced and sparser compared to more typical species.
Several groups of sundews aestivate or hibernate during unfavourable seasons: the round-leaf sundew D. rotundifolia dies back to hibernacula over winter, whilst the tuberous sundews such as D. peltata and D. macrophylla, which are mostly native to Australia, die back during the dry summer months to a resting tuber. The pygmy sundews, such as D. pygmaea, generally do not die back, but do seasonally produce small scales (gemmae), which aid in asexual reproduction.
Like all flowering plants, sundews reproduce sexually by means of flowers. Since their leaves are adapted to catching insects, most sundews produce flowers on long scapes, which raise the flowers, and therefore the approach of would-be pollinators, safely out of harm's way.
There are upwards of a hundred and fifty species of sundew, which are listed below. The classification of this genus has been recently revised: the list below reflects the classification of Jan Schlauer (available at Omnisterra (http://www.omnisterra.com/bot/cp_home.cgi)), rather than Allen Lowrie's older scheme.
Species
- Drosera acaulis
- Drosera adelae : Adelaide sundew or Lance leaved sundew
- Drosera affinis
- Drosera afra
- Drosera alba
- Drosera aliciae : Alice sundew
- Drosera andersoniana
- Drosera androsacea : Cone sundew
- (Drosera anglica : English sundew - an amphiploid hybrid between D.rotundifolia and D. linearis)
- Drosera arcturi
- Drosera arenicola
- Drosera arenicola var. occidentalis
- Drosera banksii
- Drosera barbigera : Drummond's sundew (previously D. drummondii)
- Drosera barbigera subsp. silvicola
- Drosera bequaertii
- Drosera biflora
- Drosera binata : Fork-leaf sundew (various forms, with 2, 4, 8 or more branched leaves have been variously called D. dichotoma (the Stagshorn sundew), D. multifida, D. extrema, etc.)
- Drosera brevicornis
- Drosera brevifolia : Dwarf sundew
- Drosera broomensis
- Drosera browniana
- Drosera bulbigena
- Drosera bulbosa : Red-leaved sundew
- Drosera burkeana
- Drosera burmannii
- Drosera caduca
- Drosera callistos
- Drosera camporupestris
- Drosera capensis : Cape sundew
- Drosera capillaris : Pink sundew
- Drosera cayennensis
- Drosera cendeensis
- Drosera chrysolepis
- Drosera cistiflora : Cistus-flowered sundew
- Drosera citrina
- Drosera citrina var. nivea
- Drosera closterostigma
- Drosera collinsiae
- Drosera colombiana
- Drosera communis
- Drosera communis var. pauciflora
- Drosera cuneifolia
- Drosera darwinensis
- Drosera derbyensis
- Drosera dichrosepala : Rusty sundew
- Drosera dichrosepala subsp. enodes
- Drosera dielsiana
- Drosera dilatatopetiolaris
- Drosera echinoblastus
- Drosera elongata
- Drosera eneabba
- Drosera ericksoniae
- Drosera erythrogyne
- Drosera erythrorhiza : Red ink sundew
- Drosera erythrorhiza subsp. collina
- Drosera erythrorhiza subsp. magna
- Drosera erythrorhiza subsp. squamosa
- Drosera esmeraldae
- Drosera falconeri
- Drosera felix
- Drosera filiformis : Thread leaf sundew
- Drosera filiformis var. tracyi
- Drosera fimbriata
- Drosera fulva
- Drosera gigantea : Giant sundew
- Drosera gigantea var. geniculata
- Drosera glabripes
- Drosera glanduligera : Scarlet sundew
- Drosera graminifolia
- Drosera graniticola
- Drosera graomogolensis
- Drosera grantsaui
- Drosera grievei
- Drosera hamiltonii
- Drosera hartmeyerorum
- Drosera helodes
- Drosera heterophylla : Swamp rainbow sundew
- Drosera hilaris : Hilarious sundew
- Drosera hirtella
- Drosera hirticalyx
- Drosera huegelii
- Drosera humbertii
- Drosera hyperostigma
- Drosera indica
- Drosera insolita
- Drosera intermedia : Love-nest sundew
- Drosera intricata
- Drosera kaieteurensis
- Drosera katangensis
- Drosera kenneallyi
- Drosera lanata
- Drosera lasiantha
- Drosera leucoblasta : Wheel sundew
- Drosera linearis : Linear sundew
- Drosera lowriei
- Drosera macrantha : Bridal rainbow sundew
- Drosera macrophylla : Snowy sundew
- Drosera madagascariensis
- Drosera mannii
- Drosera marchantii
- Drosera marchantii subsp. prophylla
- Drosera menziesii : Pink rainbow sundew
- Drosera menziesii subsp. basifolia
- Drosera menziesii subsp. penicillaris
- Drosera menziesii subsp. thysanosepala : Fringed sundew
- Drosera meristocaulis
- Drosera microphylla : Purple sundew
- Drosera miniata : Orange sundew
- Drosera modesta : Modest rainbow sundew
- Drosera montana : Mountain sundew
- Drosera montana var. schwackei
- Drosera montana var. tomentosa
- Drosera moorei
- Drosera myriantha
- Drosera natalensis
- Drosera neesii : Jewel rainbow sundew
- Drosera neesii subsp. borealis
- Drosera neocaledonica
- Drosera nidiformis
- Drosera nitidula : Shining sundew
- Drosera nitidula subsp. omissa
- Drosera nitidula subsp. allantostigma
- Drosera nitidula subsp. leucostigma
- Drosera oblanceolata
- Drosera occidentalis : Western sundew
- Drosera occidentalis subsp. australis
- Drosera occidentalis var. macroscapa
- Drosera orbiculata
- Drosera ordensis
- Drosera oreopodion
- Drosera paleacea
- Drosera paleacea subsp. leioblastus
- Drosera paleacea subsp. roseana
- Drosera paleacea subsp. stelliflora
- Drosera paleacea subsp. trichocaulis
- Drosera pallida
- Drosera panamensis
- Drosera paradoxa
- Drosera parvula
- Drosera parvula subsp. sargentii
- Drosera pauciflora
- Drosera pedicellaris
- Drosera peltata : Shield sundew or pale rainbow sundew
- Drosera peltata subsp. auriculata : Tall rainbow sundew
- Drosera peruensis
- Drosera petiolaris : Woolly sundew
- Drosera pilosa
- Drosera platypoda
- Drosera platystigma : Black-eyed sundew
- Drosera prolifera : Hen and chickens sundew
- Drosera prostratoscaposa
- Drosera pulchella : Pretty sundew
- Drosera pycnoblasta : Pearly sundew
- Drosera pygmaea : Pygmy sundew
- Drosera radicans
- Drosera ramellosa
- Drosera ramentacea : Long-stemmed sundew
- Drosera rechingeri
- Drosera regia : King sundew
- Drosera roraimae
- Drosera rosulata
- Drosera rotundifolia : Round-leafed sundew
- Drosera salina
- Drosera schizandra : Notched sundew
- Drosera scorpioides : Shaggy sundew
- Drosera sessilifolia
- Drosera sewelliae : Red woolly sundew
- Drosera slackii : Slack's sundew
- Drosera spatulata : Spoon-leafed sundew
- Drosera spilos
- Drosera stenopetala
- Drosera stolonifera : Leafy fan sundew
- Drosera stolonifera subsp. compacta
- Drosera stolonifera subsp. humilis
- Drosera stolonifera subsp. monticola
- Drosera stolonifera subsp. porrecta
- Drosera stolonifera subsp. prostrata
- Drosera stolonifera subsp. rupicola
- Drosera stricticaulis : Erect sundew
- Drosera stricticaulis subsp. eremaea
- Drosera subhirtella : Sunny rainbow sundew
- Drosera subtilis
- Drosera sulphurea : Sulfur flowered sundew
- Drosera tentaculata
- Drosera trinervia
- Drosera tubaestylis
- Drosera uniflora
- Drosera villosa : Hairy sundew
- Drosera viridis
- Drosera walyunga
- Drosera whittakeri : Scented sundew
- Drosera yutajensis
- Drosera zigzagia
- Drosera zonaria : Painted sundew
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