Dendrophylax

Dendrophylax
Dendrophylax lindenii
Scientific classification
Kingdom: Plantae
(unranked): Angiosperms
(unranked): Monocots
Order: Asparagales
Family: Orchidaceae
Subfamily: Epidendroideae
Tribe: Vandeae
Subtribe: Angraecinae
Alliance: Campylocentrum
Genus: Dendrophylax
Rchb.f.
Synonyms[1]
  • Polyrrhiza Pfitzer in H.G.A.Engler & K.A.E.Prantl
  • Harrisella Fawc. & Rendle
  • Polyradicion Garay

Dendrophylax is a genus of leafless neotropical orchids (family Orchidaceae) native to Mexico, Central America, the West Indies, and Florida.[1][2][3] The name is from Greek δένδρον ("tree") and φύλαξ ("guard; keeper"). One species, Dendrophylax lindenii, featured heavily in the book The Orchid Thief.

Biology

The plants of his genus are unusual in that they consist of masses of photosynthetic roots anchored in trees with a highly reduced stem and ephemeral leaves which have been reduced to scales. The bulk of these plants consists only of flat, cord-like, green roots with distinctive "track marks". These white track marks are called pneumatodes and function in much the same manner as stomata allowing the photosynthetic roots to perform gas exchange to support photosynthesis.

Phylogeny

Members of this genus are distant relatives of the African and Indian Ocean genus Angraecum; it seems that orchid seed, blowing like dust, crossed the Atlantic at least once and successfully colonized new habitat. Current evidence derived from molecular studies indicates that the original arrival from Africa which spawned this genus and the related genus Harriselia was a member of the subtribe Angraecineae with small leaves and flowers and a monopodial growth habit, and the leafless habit developed in parallel in both Africa and the Caribbean, since the genes are present in all members of the subtribe Angraecineae and the leafless habit is common in several genera within the Vandeae (Chilochista, Aerangidinae, Angraecineae, Sarcanthinae, Telipogoninae, Dendrophylax, and Harriselia).

Cultivation

Several species such as Dendrophylax funalis, Dendrophylax fawcetti, and Dendrophylax lindenii produce large, showy, white flowers which are highly fragrant and described as smelling fruity and reminiscent of an apple. Most members of this genus are pollinated by various species of moths with very long probosces and the flowers of most species within this genus possess very long nectar spurs ranging from 4 to 8 inches in length on average. The giant sphinx moth is known to pollinate several species within this genus.

Dendrophylax funalis is more commonly and easily cultivated that other members of the genus and the plants tend to get very large and robust in both habitat and cultivation. Other members of this genus are very difficult subjects in cultivation such as Dendrophylax lindenii, and some members of this genus defy cultivation or are of little interest to orchid enthusiasts because they produce very small flowers.[4]

Species

Species accepted as of June 2014:[1]

  1. Dendrophylax alcoa - Dominican Republic
  2. Dendrophylax barrettiae - Dominican Republic, Haiti, Jamaica, Cuba
  3. Dendrophylax constanzensis - Dominican Republic
  4. Dendrophylax fawcetti - Grand Cayman Island
  5. Dendrophylax filiformis - Dominican Republic, Haiti, Jamaica, Cuba, Puerto Rico
  6. Dendrophylax funalis - Jamaica
  7. Dendrophylax gracilis - Cuba
  8. Dendrophylax helorrhiza - Dominican Republic
  9. Dendrophylax lindenii - Florida, Bahamas, Cuba
  10. Dendrophylax macrocarpus - Dominican Republic
  11. Dendrophylax porrectus - Mexico, El Salvador, Guatemala, Florida, Cayman Islands, Cuba, Hispaniola, Jamaica, Puerto Rico
  12. Dendrophylax sallei - Dominican Republic
  13. Dendrophylax serpentilingua - Dominican Republic
  14. Dendrophylax varius - Cuba, Haiti

References

  1. 1 2 3 Kew World Checklist of Selected Plant Families
  2. Nir, M. Orchidaceae Antillanae, 82-87, 2000.
  3. Carlsward, B.S., Whitten, W.M. & Williams, N.H. (2003). Molecular phylogenetics of Neotropical leafless Angraecinae (Orchidaceae). Reevaluation of generic concepts. International Journal of Plant Sciences 164: 43-51.
  4. Illustrated Encyclopedia of Orchids ISBN 0-88192-267-6

External links

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