Dieffenbachia


Dieffenbachia is a genus of tropical flowering plants in the family Araceae. It is native to the New World Tropics from Mexico and the West Indies south to Argentina. Some species are widely cultivated as ornamental plants, especially as houseplants, and have become naturalized on a few tropical islands.
Dieffenbachia is a perennial herbaceous plant with straight stem, simple and alternate leaves containing white spots and flecks, making it attractive as indoor foliage. Species in this genus are popular as houseplants because of their tolerance of shade. Its English names, dumb cane and mother-in-law's tongue refer to the poisoning effect of raphides, which can cause temporary inability to speak. Dieffenbachia was named by Heinrich Wilhelm Schott, director of the Botanical Gardens in Vienna, to honor his head gardener Joseph Dieffenbach.

Species

The World Checklist of Selected Plant Families lists the following species:
  1. Dieffenbachia aglaonematifolia Engl. – Brazil, Paraguay; Corrientes + Misiones Provinces of Argentina
  2. Dieffenbachia antioquensis Linden ex Rafarin – Colombia
  3. Dieffenbachia aurantiaca Engl – Costa Rica, Panama
  4. Dieffenbachia beachiana Croat & Grayum – Costa Rica, Panama
  5. Dieffenbachia bowmannii Carrière – Colombia, northwestern Brazil
  6. Dieffenbachia brittonii Engl. – Colombia
  7. Dieffenbachia burgeri Croat & Grayum – Costa Rica
  8. Dieffenbachia cannifolia Engl. – Colombia, Ecuador, Peru
  9. Dieffenbachia concinna Croat & Grayum – Costa Rica, Nicaragua
  10. Dieffenbachia copensis Croat – Panama
  11. Dieffenbachia cordata Engl. – Peru
  12. Dieffenbachia costata Klotzsch ex Schott – Colombia, Ecuador, Peru
  13. Dieffenbachia crebripistillata Croat – Panama
  14. Dieffenbachia daguensis Engl. – Colombia, Ecuador
  15. Dieffenbachia davidsei Croat & Grayum – Costa Rica
  16. Dieffenbachia duidae G.S.Bunting – Venezuela, Guyana
  17. Dieffenbachia elegans A.M.E.Jonker & Jonker – Bolivia, northwestern Brazil, the Guianas
  18. Dieffenbachia enderi Engl. – Colombia
  19. Dieffenbachia fortunensis Croat – Panama
  20. Dieffenbachia fosteri Croat – Panama
  21. Dieffenbachia fournieri N.E.Br. – Colombia
  22. Dieffenbachia galdamesiae Croat – Panama
  23. Dieffenbachia gracilis Huber – Peru, northwestern Brazil
  24. Dieffenbachia grayumiana Croat – Costa Rica, Panama, Colombia
  25. Dieffenbachia hammelii Croat & Grayum – Costa Rica, Nicaragua
  26. Dieffenbachia herthae Diels – Ecuador
  27. Dieffenbachia horichii Croat & Grayum – Costa Rica
  28. Dieffenbachia humilis Poepp. – Bolivia, Peru, Ecuador, northwestern Brazil, the Guianas
  29. Dieffenbachia imperialis Linden & André – Peru
  30. Dieffenbachia isthmia Croat – Panama
  31. Dieffenbachia killipii Croat – Panama
  32. Dieffenbachia lancifolia Linden & André – Colombia
  33. Dieffenbachia leopoldii W.Bull – Colombia
  34. Dieffenbachia longispatha Engl. & K.Krause – Honduras, Nicaragua, Costa Rica, Panama, Colombia, Venezuela
  35. Dieffenbachia lutheri Croat – Panama
  36. Dieffenbachia macrophylla Poepp. – Peru
  37. Dieffenbachia meleagris L.Linden & Rodigas – Ecuador
  38. Dieffenbachia nitidipetiolata Croat & Grayum – Panama
  39. Dieffenbachia obliqua Poepp. – Peru
  40. Dieffenbachia obscurinervia Croat – Panama
  41. Dieffenbachia oerstedii Schott – southern Mexico, Central America, Colombia
  42. Dieffenbachia olbia L.Linden & Rodigas – Peru
  43. Dieffenbachia paludicola N.E.Br. ex Gleason – northwestern Brazil, the Guianas, Venezuela
  44. Dieffenbachia panamensis Croat – Panama
  45. Dieffenbachia parlatorei Linden & André – Colombia, Venezuela
  46. Dieffenbachia parvifolia Engl. – northwestern Brazil, Bolivia, Ecuador, Peru, Venezuela
  47. Dieffenbachia pittieri Engl. & K.Krause – Panama
  48. Dieffenbachia seguine Schott – West Indies, south to Brazil and Bolivia
  49. Dieffenbachia shuttleworthiana Regel – Colombia
  50. Dieffenbachia standleyi Croat – Honduras
  51. Dieffenbachia tonduzii Croat & Grayum – Nicaragua, Costa Rica, Panama, Colombia, Ecuador
  52. Dieffenbachia weberbaueri Engl. – Peru
  53. Dieffenbachia weirii Berk. – Colombia
  54. Dieffenbachia wendlandii Schott – southern Mexico south to Panama
  55. Dieffenbachia williamsii Croat – Bolivia
  56. Dieffenbachia wurdackii Croat – Peru
Dieffenbachia includes a number of unresolved taxonomic names, such as Dieffenbachia amoena.

Ecology

In a survey which began in 1998, researchers in Costa Rica noticed that the strawberry poison frog Oophaga pumilio, deposited almost all of their tadpoles on the leaf axils of Dieffenbachia. As a result, the frog population fluctuated with the abundance of Dieffenbachia, especially in secondary forest. A majority of the plants were eradicated by 2012 when the surveyors returned to the same area, with only 28% of 2002 plant numbers remaining. Researchers concluded that the reason for the rapid decline in Dieffenbachia was due to increased abundance of the collared peccary Pecari tajacu in the La Selva Biological Station research area; a small pig-like animal which feeds on Dieffenbachia and other plants.

Cultivation

With a minimum temperature of, dieffenbachia must be grown indoors in temperate areas. They need light, but filtered sunlight through a window is usually sufficient. They also need moderately moist soil, which should be regularly fertilized with a proprietary houseplant fertilizer. Leaves will periodically roll up and fall off to make way for new leaves. Yellowing of the leaves is generally a sign of problematic conditions, such as a nutrient deficiency in the soil. Dieffenbachia respond well to hot temperatures and dry climates.
Dieffenbachia prefer medium sunlight, moderately dry soil and average home temperatures of. Most require water about twice a week.
As Dieffenbachia seguine comes from the tropical rain forest, it prefers to have moisture at its roots, as it grows all the time, it needs constant water, but with loose well aerated soils.
The cultivars 'Camille' and 'Tropic Snow' have gained the Royal Horticultural Society's Award of Garden Merit.

Toxicity

The cells of the Dieffenbachia plant contain needle-shaped calcium oxalate crystals called raphides. If a leaf is chewed, these crystals can cause a temporary burning sensation and erythema. In rare cases, edema of tissues exposed to the plant has been reported. Mastication and ingestion generally result in only mild symptoms. With both children and pets, contact with dieffenbachia can cause a host of unpleasant symptoms, including intense numbing, oral irritation, excessive drooling, and localized swelling. However, these effects are rarely life-threatening. In most cases, symptoms are mild, and can be successfully treated with analgesic agents, antihistamines, or medical charcoal. Moreover, severe cases can occur if Dieffenbachia makes prolonged contact with oral mucosal tissue. In such cases, symptoms generally include severe pain which can last for several days to weeks. Hospitalization may be necessary if prolonged contact is made with the throat, in which severe swelling has the potential to affect breathing. Gastric evacuation or lavage is "seldom" indicated. In patients with exposure to toxic plants, 70% are children younger than 5 years.
Stories that Dieffenbachia is a deadly poison are urban legends.