TILOSOMES IN ROOTS OF ORCHIDACEAE: MORPHOLOGY AND SYSTEMATIC OCCURRENCE
1983; Wiley; Volume: 70; Issue: 9 Linguagem: Inglês
10.1002/j.1537-2197.1983.tb07926.x
ISSN1537-2197
AutoresAlec M. Pridgeon, William Stern, David H. Benzing,
Tópico(s)Plant Diversity and Evolution
ResumoTilosomes, also called “fibrous bodies” or “rod bodies” in older literature, are lignified excrescences from the walls of cells of the innermost velamen cell layer adjacent to thin‐walled passage cells of the exodermis in roots of many epiphytic orchids. Seven broad morphological types are recognized: spongy, lamellate, discoid, webbed, meshed, baculate, and plaited. Some types characterize specific genera or subtribes of Orchidaceae. Of the 350 species in 175 genera included in a survey of the family, tilosomes occur in 95 species and 39 genera and are concentrated in tribe Polystachyeae and subtribes Sobraliinae, Coelogyninae, Laeliinae, Pleurothallidinae, Bulbophyllinae, Lycastinae, and Maxillariinae. With the exception of the pantropical genera Bulbophyllum and Polystachya and the Paleotropical subtribe Coelogyninae, tilosomes are almost exclusively Neotropical phenomena.
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