Rhaphidophora

Rhaphidophora
Rhaphidophora celatocaulis
Scientific classification
Kingdom: Plantae
(unranked): Angiosperms
(unranked): Monocots
Order: Alismatales
Family: Araceae
Subfamily: Monsteroideae
Tribe: Monstereae
Genus: Rhaphidophora
Hassk., 1842
Synonyms[1]

Rhaphidophora is a genus in the family Araceae, occurring from tropical Africa eastwards through Malesia and Australasia to the Western Pacific. The genus consists of approximately 100 species.

Description

This is a genus of evergreen, robust, climbing plants. The flowers are bisexual, lacking a perigone. The spathe is shed after flowering. The ovules number eight or more and are superposed on two (rarely 3) parietal placentas of the ovary. The flowers produce many, ellipsoid, straight seeds with a brittle and smooth outer coat (testa).

These are hemiepiphytes, plants capable of beginning life as a seed and sending roots to the soil, or beginning as a terrestrial plant that climbs a tree and then sends roots back to the soil. In rare cases they are terrestrial rheophytes (plants that grow in fast-flowing water).

Their bast fibers have typically abundant, long and slender trichosclereids, merging with the fibers of the sclerenchyma. If the blade of the leaf is torn, many hairs become apparent. The leaf stalks bend abruptly at their top. The leaf margin is entire. The leaves are pinnatifid to pinnatisect (cut with deep opposite lobing). The leaf venation is parallel (with veins running parallel for the length of the leaf), pinnate (one mid-vein with smaller veins branching off laterally) to reticulate (feather-veined).

Chemistry

Six compounds extracted from the dried leaves and stems of Rhaphidophora decursiva have been shown to possess activity against the malarial agent Plasmodium falciparum. Polysyphorin and rhaphidecurperoxin showed the strongest antimalarial activity, while rhaphidecursinol A, rhaphidecursinol B, grandisin, and epigrandisin were less active. Rhaphidecursinol A and rhaphidecursinol B were determined to be neolignans, a major class of phytoestrogens, while rhaphidecurperoxin is a new benzoperoxide.[2]

Heterotypic synonyms

Taxonomy

Research on the chloroplast DNA sequence data (trnL-F) has shown that Rhaphidophora and Epipremnum are paraphyletic, forming three informal groups with other genera of the paraphyletic tribe Monstereae. This may result in taxonomic changes in this genus.[3] The genera Rhaphidophora, Epipremnum, and Monstera are poorly differentiated.

One cultivar Rhaphidophora excelsa `Exotica' has been recognized.[4]

Selected species

An Illustration of Raphidophora pertusa.

Epipremnum aureum was once categorized in this genus.

Footnotes

  1. ↑ Kew World Checklist of Selected Plant Families
  2. ↑ Hong-Jie Zhang, Pamela A. Tamez, Vu Dinh Hoang, Ghee Teng Tan, Nguyen Van Hung, Le Thi Xuan, Le Mai Huong, Nguyen Manh Cuong, Do Thi Thao, D. Doel Soejarto, Harry H. S. Fong, and John M. Pezzuto (June 2001). "Antimalarial Compounds from Rhaphidophora decursiva". J. Nat. Prod. 64 (6): 772–777. doi:10.1021/np010037c. PMID 11421741.
  3. ↑ TAM Sheh-May ; BOYCE Peter C. ; UPSON Tim M. ; BARABE Denis ; BRUNEAU Anne ; FOREST Felix ; PARKER John S. (2004). "Intergeneric and infrafamilial phylogeny of subfamily Monsteroideae (Araceae) revealed by chloroplast trnL-F sequences". American Journal of Botany 91 (3): 490–498. doi:10.3732/ajb.91.3.490. PMID 21653404.
  4. ↑ Aroid cultivar registry

References

External links

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