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Nematanthus

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Nematanthus
Nematanthus wettsteinii showing the distinctive "goldfish" flower of some species in the genus
Scientific classification Edit this classification
Kingdom: Plantae
Clade: Tracheophytes
Clade: Angiosperms
Clade: Eudicots
Clade: Asterids
Order: Lamiales
Family: Gesneriaceae
Subfamily: Gesnerioideae
Genus: Nematanthus
Schrad.[1]
Synonyms[1]
  • Hypocyrta Mart.
  • Orobanchia Vand.

Nematanthus is a genus of flowering plants in the family Gesneriaceae. All of its species are endemic to Brazil.[1] Compared to other gesneriads, Nematanthus has leaves that are small, succulent, and hard-surfaced. The plant has a trailing, branching, and spreading habit; it is generally an epiphyte in nature and a hanging-basket plant in cultivation. The flower has fused petals. In some species, the flower has a "pouch" at the bottom. The fancied resemblance of such flowers to a goldfish gives these plants the common name goldfish plant or guppy plant.

Hummingbirds will often feed from the nectar-filled "goldfish" flowers.

Description

Nematanthus species are perennials or subshrubs, typically growing epiphytically, less often in humus-filled pockets on rocks. Their leaves are often reddish underneath. Their flowers have fused petals and vary quite widely in shape. Some have flowers with a "pouch" on the lower surface of the flower and a small opening (particularly those commonly cultivated). Others have flowers that are twisted through 180° when fully open (resupinate), so that if pouched, the pouch is at the top. Resupinate flowers may be brightly coloured, funnel-shaped and compressed from side to side, or white and bell-shaped. Some species have flowers that are borne on long pedicels and hang down below the plant, others have short pedicels so that the flowers are close to the stem.[2][3]

Taxonomy

The genus Nematanthus was first described by Heinrich Adolph Schrader in 1821,[4] with the only species (and so the type species) being Nematanthus corticola,[5] one of the species with flowers hanging down on long pedicels.[3] The name Nematanthus is from Ancient Greek nema meaning 'thread' and anthos meaning 'flower', referring to the 20 cm (8 in) long pedicels of the type species.[3]

Nematanthus is placed in the subfamily Gesnerioideae, tribe Gesnerieae, subtribe Columneinae.[6] Within the subtribe, it forms a clade with Codonanthe, Codonanthopsis and Lesia:[7][8]

Lesia

Codonanthopsis

Codanthe

Nematanthus

Species

As of April 2021, Plants of the World Online accepted the following species:[1]

Cultivation

Nematanthus thrive between 18 to 25 °C (64 to 77 °F), although they stay more compact if grown at 15 to 17 °C (59 to 63 °F).[9] They may lose their leaves if temperatures go above this level.[9][10] Nematanthus gregarius is said to tolerate temperatures down to −1 to 2 °C (30 to 35 °F).[11] Nematanthus do best in bright indirect light,[9] and can easily burn in direct sunlight. They prefer high humidity, and grow better under these conditions, but adapt to household humidity.[10][12] The tuberous roots of this plant retain water, and Nematanthus prefer the soil to remain moist, and well-drained. The goldfish plant enjoys being pot-bound, and is more likely to bloom in that state. When grown in the right conditions, Nematanthus is known to bloom year-round. To encourage new blooms, regular pruning of the plant is recommended.[13] Plants can be propagated from cuttings.[9]

Cultivars

Nematanthus 'Tropicana'
Nematanthus gregarius 'Dibley's Gold'

'Tropicana' originated from a cross made in the United States by W. R. Saylor. The parents were reported to be N. perianthomegus and N. gregarius.[9] As of April 2021, N. perianthomegus was treated as a synonym of N. hirtellus by Plants of the World Online,[14] although other sources say that it is a synonym of N. tessmannii.[3] 'Tropicana' is initially upright, after which older branches trail. The leaves are 5 by 2.5 cm (2.0 by 1.0 in), glossy dark green with a reddish brown margin on the under surface. The flower has a red-brown calyx, the fused petals (perianth) being yellow with red-brown stripes and spots. 'Tropicana' produces flower buds all year round.[9]

'Rio' also originated from a cross by Saylor, in this case between N. gregarius and N. fissus (syn. Hypocyrta selloana). Its leaves are slightly larger than those of 'Tropicana', 6 by 6 cm (2.4 by 2.4 in), lighter green on both sides and less glossy. The flower is smaller, with a light green calyx and a striking orange-red perianth. 'Rio' makes buds all year round.[9]

'Herens' is of unknown origin. It resembles 'Tropicana', with a somewhat smaller leaf, 4.5 by 2 cm (1.8 by 0.8 in), with a reddish tinge on the underside. The calyx is red-green and the perianth orange-red. It can flower abundantly all year round.[9]

'Gietvoz' is also of unknown origin. It is a compact cultivar, less sensitive to unfavorable growing conditions such as overwatering or bright light. The leaf is smaller, 3.5 by 2 cm (1.4 by 0.8 in), and less tapered than that of other cultivars, and is thick, waxy and glossy. The underside of the leaf is red with a green edge and is clearly visible as the leaves are somewhat upright. The flower has an inconspicuous light green calyx and an orange-yellow perianth. Although 'Gietvoz' does not flower as readily as other cultivars, it has a good growth habit and attractive foliage.[9]

Saylor also made crosses between Codonanthe gracilis and Nematanthus hybrids, creating the hybrid genus × Codonatanthus. Two of the resulting cultivars are 'Fiesta' and 'Aurora'.[15][9]

Nematanthus gregarius 'Dibley's Gold' has variegated leaves.[10]

Toxicity

Nematanthus is considered non-toxic and safe for pets by the ASPCA.[16]

References

  1. ^ a b c d "Nematanthus Schrad.". Plants of the World Online. Royal Botanic Gardens, Kew. Retrieved 2021-04-04.
  2. ^ Chautems, A. & Perret, M. (2017). "Description and phylogenetic position of a new species of Nematanthus (Gesneriaceae) from Bahia, Brazil" (PDF). Candollea. 72: 351–359. doi:10.15553/c2017v722a13. Retrieved 2021-04-05.
  3. ^ a b c d "The Genus Nematanthus" (PDF). The Newsletter of the Delaware African Violet and Gesneriad Society. 13 (4). 2010.
  4. ^ "Nematanthus Schrad.". The International Plant Names Index. Retrieved 2021-04-05.
  5. ^ Schrader, H.A. (1821). "72 Stück". Gottingische Gelehrte Anzeigen unter der Aufsicht der Konigl. Gesellschaft der Wissenschaften (in German). 20: 705–720. p. 718.
  6. ^ Weber, A.; Middleton, D.J.; Clark, J.L. & Möller, M. (2020). "Keys to the infrafamilial taxa and genera of Gesneriaceae". Rheedea. 30 (1): 5–47. doi:10.22244/rheedea.2020.30.01.02.
  7. ^ Smith, James F. & Clark, John L. (2013). "Molecular Phylogenetic Analyses Reveal Undiscovered Monospecific Genera in the tribe Episcieae (Gesneriaceae)" (PDF). Systematic Botany. 38 (2): 451–463. doi:10.1600/036364413X666723. JSTOR 24546074. Retrieved 2021-04-05.
  8. ^ Chautems, Alain & Perret, Mathieu (2013). "Redefinition of the Neotropical Genera Codonanthe (Mart.) Hanst. and Codonanthopsis Mansf. (Gesneriaceae)" (PDF). Selbyana. 31 (2): 143–156. Retrieved 2021-04-05.
  9. ^ a b c d e f g h i j Lentjes, P.W.M. (1986). "Nematanthus-cultivars uit VS en Ierland : Perspectief biedende nieuwe, bloeiende potplanten". Vakblad voor de Bloemisterij (in Dutch). 37: 44–47. Reproduced as Bijlage ('Appendix') 7, pp. 28–30, in Lentjes, P.W.M. (1987). Produktvernieuwing bij Potplanten Gesneriaceae (Intern Verslag nr. 31) (in Dutch). Aalsmeer: Proefstation voor de Bloemisterij in Nederland. Retrieved 2021-04-04.
  10. ^ a b c Maxwell, Alcie. "Nematanthus". The Gesneriad Reference Web. The Gesneriad Society. Retrieved 2021-04-04.
  11. ^ "Plant database entry for Goldfish Plant (Nematanthus gregarius) with 10 images and 26 data details". garden.org. Retrieved 2019-05-09.
  12. ^ "Goldfish Plant Care: Growing And Caring For Columnea Plants". Plant Care Today. 2018-07-24. Retrieved 2019-05-09.
  13. ^ "Goldfish Plant Care Tips - Columnea gloriosa". www.guide-to-houseplants.com. Retrieved 2019-05-09.
  14. ^ "Nematanthus perianthomegus (Vell.) H.E.Moore". Plants of the World Online. Royal Botanic Gardens, Kew. Retrieved 2021-04-05.
  15. ^ Saylor, W.R. (1978). "The first intergeneric hybrid between Codonanthe and Nematanthus (Gesneriaceae)". Selbyana. 5 (1): 1–3. JSTOR 41759513. Retrieved 2021-04-04.
  16. ^ "Gold-Fish Plant". ASPCA. Retrieved 2019-05-09.