| Drosera falconeri | |
|---|---|
 | |
Scientific classification  | |
| Kingdom: | Plantae |
| Clade: | Tracheophytes |
| Clade: | Angiosperms |
| Clade: | Eudicots |
| Order: | Caryophyllales |
| Family: | Droseraceae |
| Genus: | Drosera |
| Subgenus: | Drosera subg. Lasiocephala |
| Species: | D. falconeri |
| Binomial name | |
| Drosera falconeri | |
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| Distribution of D. falconeri in Australia | |
Drosera falconeri is a carnivorous plant in the family of Droseraceae. It is endemic to the Northern Territory of Australia.
Drosera falconeri superficially resembles the Venus flytrap (Dionaea muscipula). [2] [3] In a review of the research on the evolution of the Venus flytrap from sticky-leaved ancestors, botanists Thomas Gibson and Donald Waller use D. falconeri as an example of a sticky-leaved species that shares many characteristics with the Venus flytrap, such as a wide petiole and lamina, and faces the same challenge of prey escape that the snap trap of the Venus flytrap evolved in response to. [3]
Drosera falconeri is a tropical perennial plant with a rosette body plan that is common for the genus Drosera. Deciduous leaves lay flat against the soil. Leaves are usually smaller at anthesis (flowering), but increase as the growing season progresses. [4] Typical reniform lamina at maturity are 1.5 cm (0.6 in) long and 2 cm (0.8 in) wide, [4] with leaves on older specimens being as wide as 3 cm (1.2 in). [5] It is unique in the subgenus because of its large leaves that are typically flat against the soil. [5] Retentive mucilage-producing glands held on stalks – structures known as tentacles – appear on the margin of the lamina with shorter glands in the center of the leaf. The abaxial (underside) surface of the leaf is noticeably veined and sparsely covered with non-glandular white hairs. Petioles are oblanceolate and usually 10 mm long with varying widths: 2 mm near the center of the rosette, 3.5 mm near the center of the petiole, and 3 mm at the point of attachment to the lamina. The upper surface of the petiole is glabrous, but the margins and lower surface possess hairs similar to those of the abaxial leaf surface. [4]
One or two racemose inflorescences are produced per plant and are usually 8 cm (3.1 in) long. Approximately 12 flowers are found on one inflorescence with each white or pink flower held on a 3–5 mm long pedicel. The scape, inflorescence, and sepals are sparsely covered in white hairs. Flowers are composed of elliptic 3 mm long by 1.8 mm wide sepals, 7 mm long by 4 mm wide petals, five 2.7 mm long white stamens that produce orange anthers and pollen, a 1.1 mm diameter ovary with bilobed carpels and three white 2.5 mm long styles that are extensively branched toward the apex with terminal white stigmas. It typically flowers from November to December with only one flower open at a time, lasting for just one day whether it was pollinated or not. [4]
In the dry season the leaves die back and the plant survives by forming a bulb-like structure of tightly packed leaf bases just below the soil's surface. This adaptation helps it avoid desiccation during the dry season. The hard clay soils acts as insulation; all other species in subgenus Lasiocephala use dense white hairs for insulation. Dormancy is typically broken with the first rains of the wet season and growth proceeds quickly. New growth, such as a new fibrous root system, new leaves, and the inflorescence, must build up reserves and set seed; a short wet season and sudden drought may cut the growing season considerably. New roots are white and fleshy, mostly serving as a water storage organ, while older roots become thinner and mostly anchor the plant. [4]
It can readily hybridise with other species in the D. petiolaris complex, which includes the species in the subgenus Lasiocephala. [7] Hybridisation is rare in the wild, however, because the soil types specific to individual parent species do not converge often. The first natural hybrid to be discovered was the product of D. falconeri and D. dilatato-petiolaris , [4] later given the nomen nudum D. dilaconeri in 1991 by E. Westphal. [1] Seed from this hybrid has proved to be viable which is an unusual characteristic for Drosera hybrids. [4] Approximately four recognisable forms of this hybrid can be found in the wild. The characteristics favour one parent species or the other: some forms are smaller at 4–5 cm (1.6–2.0 in) in diameter while others can be up to 10 cm (3.9 in) in diameter, the leaf varies in size, and some hybrids will form clumps by producing plantlets like D. dilatato-petiolaris does while others will remain isolated. [5] Drosera falconeri also hybridises with D. petiolaris; this hybrid was given the nomen nudumD. petioconeri by Westphal in 1991. [1]
Artificial hybrids involving D. falconeri have also been produced and cultivated, including a complex hybrid: (D. falconeri × D. ordensis ) × ( D. darwinensis × D. falconeri). [8]
Drosera falconeri is common throughout the northern coastal areas of the Northern Territory in Australia. It was originally located along the Finniss River in alkaline sandy soils. [5] [9] It is found growing in the grey silty clay soils in the Palmerston and Berry Springs regions and on Melville Island. [4]
While most carnivorous plants are calcifuges that cannot tolerate alkaline soils, D. falconeri grows on calcareous sandy soils with high pH values. [10] [11] In the first account of this species' habitat, the soil pH at the site was recorded as pH 8. [12] At the site where D. falconeri was first discovered, tall dense grass covered the small population. [12]
Drosera falconeri was first discovered by a Mr Falconer in 1980 along the Finniss River in the Northern Territory. Falconer was collecting plants and tropical fish for Peter Tsang, a carnivorous plant enthusiast living in Queensland. Tsang then sent specimens on to Allen Lowrie and Bill Lavarack, a botanist with the Queensland National Parks. Tsang also prepared a short announcement of this new species published in the June 1980 issue of the Carnivorous Plant Newsletter , giving a brief description and suggesting the specific epithet honour Mr Falconer as its discoverer. It was not until 1984 that Katsuhiko Kondo provided the formal description required under the rules of the International Code of Botanical Nomenclature in an article that described three new species in the D. petiolaris complex. [5] [12] The holotype specimen is Kondo 2227 held at the Herbarium of Faculty of Arts and Sciences at Hiroshima University. Isotype specimens, those that are duplicates of the holotype, were distributed to several herbaria, including those at the University of North Carolina, the New York Botanical Garden, the National Herbarium of New South Wales, and the Queensland Herbarium. [13] [14]
The species was only known from a single location, the description of which vaguely positioned it along the Finniss River, a river that is nearly 100 km (60 mi) long. Tsang died in 1984 and it was feared that the exact location of the known population was lost with him. Further field studies, however, produced several new sites. [5]
Its alliance with the D. petiolaris complex in subgenus Lasiocephala was suspected from its earliest description by Peter Tsang, who noted similarities in their dormant bud and root structures. [12] This assessment has been confirmed by further analysis by other botanists. [4]
Drosera falconeri was first cultivated by Peter Tsang shortly after its initial discovery. He then sent living specimens on to others to establish the new species in cultivation. [5] [12]
It is considered to be a difficult species to grow in cultivation. During its seasonal dormancy, D. falconeri produces a tight rosette of leaves that resembles a hibernating bud. It is often grown in a peat:sand or perlite soil. Plants can be vegetatively propagated by submerging leaf pullings in pure water. [7] Under the Australian botanist Allen Lowrie's growing conditions, species in subgenus Lasiocephala grow year-round without dormancy. Lowrie also notes that these species produce deep red foliage in the wild, a characteristic that is lost in cultivation when plants retain a greener appearance presumably caused by lower light intensities. [5]
Drosera, which is commonly known as the sundews, is one of the largest genera of carnivorous plants, with at least 194 species. These members of the family Droseraceae lure, capture, and digest insects using stalked mucilaginous glands covering their leaf surfaces. The insects are used to supplement the poor mineral nutrition of the soil in which the plants grow. Various species, which vary greatly in size and form, are native to every continent except Antarctica.
Drosera regia, commonly known as the king sundew, is a carnivorous plant in the sundew genus Drosera that is endemic to a single valley in South Africa. The genus name Drosera comes from the Greek word droseros, meaning "dew-covered". The specific epithet regia is derived from the Latin for "royal", a reference to the "striking appearance" of the species. Individual leaves can reach 70 cm (28 in) in length. It has many unusual relict characteristics not found in most other Drosera species, including woody rhizomes, operculate pollen, and the lack of circinate vernation in scape growth. All of these factors, combined with molecular data from phylogenetic analysis, contribute to the evidence that D. regia possesses some of the most ancient characteristics within the genus. Some of these are shared with the related Venus flytrap (Dionaea muscipula), which suggests a close evolutionary relationship.
Drosera adelae, commonly known as the lance-leaved sundew, is a carnivorous plant in the genus Drosera that is endemic to Queensland, Australia.
Drosera anglica, commonly known as the English sundew or great sundew, is a carnivorous flowering plant species belonging to the sundew family Droseraceae. It is a temperate species with a circumboreal range, although it does occur as far south as Japan, southern Europe, and the island of Kauai in Hawaii, where it grows as a tropical sundew. It is thought to originate from an amphidiploid hybrid of D. rotundifolia and D. linearis, meaning that a sterile hybrid between these two species doubled its chromosomes to produce fertile progeny which stabilized into the current D. anglica.
Drosera banksii, commonly known as Banks' sundew, is a small annual species in the carnivorous plant genus Drosera. The reniform-shaped leaves are attached to petioles and arranged in a circular pattern (rosette) around the stem. The 5 mm wide flowers are white. It is native to northern Australia and Southeast Asia. D. banksii was originally described by Robert Brown and validly published by Augustin Pyramus de Candolle in 1824. It is currently classified in the subgenus Lasiocephala, but expert opinion is that it is misplaced and should be reclassified with the closely allied D. subtilis.
Drosera broomensis is a small, perennial carnivorous plant in the genus Drosera that is endemic to Western Australia.
Drosera ordensis is a species of sundew, native to Australia and part of the "petiolaris complex" of sundews making up the subgenus Lasiocephala. Compared to many petiolaris sundews, it has wide petioles, which are densely covered in silvery hairs. It usually forms rosettes 8 cm across, although plants up to 20 cm in diameter have been reported.
Drosera erythrorhiza, the red ink sundew, is a perennial tuberous species in the carnivorous plant genus Drosera that is endemic to Western Australia. It grows in a rosette and is distinguished from the other species in section Erythrorhiza by its many-flowered cymose inflorescences with up to 50 individual flowers. D. erythrorhiza was first described by John Lindley in his 1839 publication A sketch of the vegetation of the Swan River Colony. In 1992, N. G. Marchant and Allen Lowrie described three new subspecies, thus also creating the autonym D. erythrorhiza subsp. erythrorhiza. The subspecies were separated from this variable species mostly by leaf morphology and distribution.
Drosera subtilis is an erect annual species in the carnivorous plant genus Drosera. It is native to northern Western Australia and a single site in the Northern Territory. In Western Australia, it has been collected from Beverley Springs Station, Bigge Island, and the Mitchell Plateau area all in the vicinity of the Kimberley region. In the Northern Territory, it has been found near Little Nourlangie Rock. It grows over sandstone near seepage margins in skeletal sandstone sand and black humus mixed soils. D. subtilis is anchored to the soil by a system of thin, fleshy roots and it lacks a tuber. It produces small carnivorous leaves along erect, reddish stems that can be 20 cm (8 in) high.
Drosera darwinensis is a perennial carnivorous plant in the genus Drosera that is endemic to the Northern Territory. Its leaves are arranged in a rosette with one rosette emerging from the root stock. It produces pink or white flowers from December to April. Drosera darwinensis grows in clayey sand from Palmerston to Berry Springs south of Darwin and east to Humpty Doo. It was first described by Allen Lowrie in 1996; the type specimen was collected 0.9 km (0.6 mi) south of Temple Avenue in Palmerston on 8 April 1990. The specific epithet darwinensis refers to region where this plant is found in abundance. It is closely related to D. brevicornis, but differs from that species by its shorter inflorescence.
Drosera derbyensis is a perennial carnivorous plant in the genus Drosera and is endemic to Western Australia. Its erect or semi-erect leaves are arranged in a rosette with one or more rosettes emerging from the root stock. The petioles are narrowly oblanceolate, 0.8–1.0 mm wide at the proximate end and 1.3–1.7 mm wide at the apex(wiki), narrowing to 0.5–0.7 mm at the laminar base. The petioles are frequently 35–45 mm long when the plant is in flower and are covered in white woolly non-dendritic hairs. The insect-trapping leaf lamina is orbicular and much shorter than the petioles at only 2–3 mm in diameter. The laminar adaxial surface is covered in insect-trapping glands. Each rosette produces 1–4 raceme inflorescences, which are 25–35 cm (10–14 in) long. Each inflorescence bears 30–50 white flowers, with flowering occurring from March to June. The upper portion of the scape and the abaxial surface of the sepals are covered with white woolly non-dendritic hairs. Its roots are fibrous. Drosera derbyensis grows in sandy soils in floodways or near rock outcrops from Derby to Beverley Springs in the Kimberley region.
Drosera dilatato-petiolaris is a carnivorous plant in the genus Drosera and is endemic to Australia, being found in both Western Australia and the Northern Territory. Its leaves are arranged in a rosette and commonly produces plantlets, eventually forming large clumps that can be over 1 ft (0.3 m) across. Green petioles emerging from the center of the rosette are typically 3–5 mm wide, but can vary. Red carnivorous leaves at the end of the petioles are small and round, with most resting on the soil surface. Inflorescences are 18 cm (7 in) long with white flowers being produced from April to May. It has a diploid chromosome number of 2n = 12.
Drosera fulva is a carnivorous plant in the genus Drosera and is endemic to the Northern Territory in Australia. Its semi-erect or prostrate leaves are arranged in a compact basal rosette. Oblanceolate petioles emerging from the center of the rosette are typically 2–3 mm wide at its widest. Red carnivorous leaves at the end of the petioles are small and round at 2–3 mm in diameter. Inflorescences are 25–45 cm (10–18 in) long with white or sometimes pink flowers being produced on 50-or-more-flowered racemes from February to May.
Drosera kenneallyi is a carnivorous plant in the genus Drosera and is endemic to the Kimberley region in northern Western Australia. Its leaves are arranged in a compact basal rosette appressed to the soil. Narrowly oblanceolate petioles emerging from the center of the rosette are typically 1.5–2.2 mm wide at their widest. Red carnivorous leaves at the end of the petioles are small at 2–3 mm in diameter and elliptic to broadly ovate. Inflorescences are 12.5–20.5 cm (5–8 in) long with white flowers being produced on 10- to 20-flowered racemes from November to December.
Drosera subg. Lasiocephala, sometimes collectively known as the petiolaris-complex, is a subgenus of 14 species in the genus Drosera. These species are distinguished by their subpeltate to peltate lamina.
Drosera lanata is a carnivorous plant in the genus Drosera and is endemic to the Northern Territory and Queensland in Australia. Its leaves are arranged in a compact basal rosette. Narrow linear petioles less than 2 mm wide emerge from the center of the rosette and hold carnivorous leaves at the end. Both petioles and the center of the rosette are densely covered in silvery dendritic hairs. These dendritic hairs afford the plant insulation and allow it to trap morning dew for additional moisture during the dry season. The leaf lamina is maroon-red and 2 mm long by 2.5 mm wide.
Drosera paradoxa is a carnivorous plant in the genus Drosera and is endemic to the Northern Territory and Western Australia. It is a perennial herb with a woody stem that can grow as tall as 30 cm (12 in). The leaves on the single terminal rosette are erect or horizontal and held at the end of linear petioles, which are typically 20–35 mm long at flowering time. The carnivorous leaves are sub-orbicular and small at 2.5–3 mm wide and 2–3 mm long. Inflorescences are 20–40 cm (8–16 in) long with pink or white flowers being produced on 50- to 70-flowered crowded racemes from July to September during the dry season.
Drosera petiolaris is a carnivorous plant in the genus Drosera and is the eponymous species of the petiolaris species complex, which mostly refers to the entire subgenus Lasiocephala. It is native to Northern Australia, including the northern regions of Western Australia, the Northern Territory, and Queensland, and New Guinea; this distribution is the largest in the subgenus and the only that extends beyond Australia. Its leaves are arranged in a compact basal rosette with long, narrow petioles emerging from the center of the rosette. Carnivorous leaves are held at the end of the petiole with long retentive glands.
Drosera viridis is a semi-erect or rosetted perennial species in the carnivorous plant genus Drosera. It is known only from Brazil, being found in eastern Paraná and São Paulo and central Santa Catarina at elevations from 550–1,100 m (1,800–3,610 ft). It may, however, also be found in adjacent Argentina, Paraguay, and Uruguay. It typically grows in waterlogged habitats among grasses in white-clayey, reddish lateritic, or humus-rich black-brown soils and is sometimes found submerged with only the leaves above water.
Drosera peruensis is a carnivorous plant of the genus Drosera, commonly known as the Peruvian sundew. This Drosera species was first identified in Peru in 2002 by Tânia Regina dos Santos Silva and Mireya D. Correa following work to update the genus Drosera for the reference text, Flora Neotropica..
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