Pachycaul
Pachycauls are plants with a disproportionately thick trunk, for their height, and relatively few branches.[1] With certain pachycaul species, particularly the more succulent varieties, they are commonly referred to as "caudiciformes", a reference to their trunk development of a moisture-filled caudex for periods of drought.
By comparison, trees with thin twigs, such as oaks (Quercus), maples (Acer) and Eucalyptus, are called leptocauls; those with moderately thick twigs, such as Plumeria, are called mesocauls. Pachycauls can be the product of exceptional primary growth (as with Arecaceae and Cycadaceae) or disproportionate secondary growth, as with the baobabs (Adansonia). The word is derived from the Greek pachy- (meaning "thick" or "stout") and the Latin caulis (meaning "stem").[2]
All of the arboreal (treelike) species of Cactaceae are pachycauls, as are most of the Arecaceae, Cycadaceae and Pandanus. The most extreme pachycauls are the floodplains, or river-bottom, varieties of the African palmyra (Borassus aethiopum), with primary growth up to 2.1 m (6 ft 11 in) thick,[3][4] and the Coquito palm (Jubaea chilensis), with its primary growth measuring up to 1.8 m (5 ft 11 in) thick.[5][6][7] The most pachycaulous cycad is Cycas thouarsii at up to 150 cm (59 in) diameter.[8] The tallest pachycaul is the Andean wax palm (Ceroxylon quindiuense), at heights of up to 66 m (217 ft),[9] and around 41 cm (16 in) in diameter. The most pachycaulous cactus are the barrel cacti (Echinocactus platyacanthus), with primary growth up to 1.3 m (4 ft 3 in) diameter.[10] The largest caudiciforme-type pachycaul is the African baobab (Adansonia digitata); one specimen of which, called the Glencoe baobab (from Hoedspruit, Limpopo, South Africa) has a basal diameter (not girth) of 16 m (52 ft).[11] However, this particular tree has suffered a severe trauma and is dying. Pachycauls also differ greatly in their rates of growth, from the half-man tree (Pachypodium namaquanum) which grows only 5 mm (0.20 in) each year[12] to the palm Pigafetta elata which can grow 2.7 m (8 ft 10 in) or more in one year.[13]
Examples occur in these genera:[14]
- Pachycormus (Anacardiaceae)
- Acanthocereus (Cactaceae)
- Peniocereus (Cactaceae)
- Alluaudia (Didiereaceae)
- Adenium (Apocynaceae)
- Crassula (Crassulaceae)
- Kalanchoe (Crassulaceae)
- Beaucarnea (Asparagaceae)
- Pachypodium (Apocynaceae)
- Dendrosenecio (Asteraceae)
- Bursera (Burseraceae)
- Cyanea (Campanulaceae)
- Lobelia (Campanulaceae)
- Dendrosicyos (Cucurbitaceae)
- Gerrardanthus (Cucurbitaceae)
- Givotia (Euphorbiaceae)
- Delonix (Fabaceae)
- Fouquieria (Fouquieriaceae)
- Adansonia (Malvaceae; subfamily Bombacoideae)
- Bombax (Malvaceae)
- Brachychiton (Malvaceae)
- Cavanillesia (Malvaceae)
- Ceiba (Malvaceae)
- Dorstenia (Moraceae)
- Stephania (Menispermaceae)
- Cyphostemma (Vitaceae).
See also
[edit]References
[edit]- ^ Gupta, I. C.; S. K. Gupta (1992). Concepts' Dictionary Of Agricultural Sciences. Concept Publishing Company. p. 348. ISBN 978-81-7022-301-6.
- ^ Stearn, W.T. (1992). Botanical Latin: History, grammar, syntax, terminology and vocabulary, Fourth edition. David and Charles.
- ^ Von Mueller, Ferdinand (1881). Select Extra-tropical Plants. Sydney: Government Printer. p. 50.
- ^ Carder, Dr. Al (2005). Giant Trees of Western America and the World. Madeira Park, British Columbia: Harbour Pub. Co. Ltd. p. 130.
- ^ anonymous (January 1957). "<not recorded>". Principes. 1 (2): 57.
- ^ Caradine, Chris (November 1998). "A Day at Ocoa". The Palm Journal. [no volumes] (143): 20 with photo.
- ^ Riverside (California) Sunday Press Enterprise (September 6, 1964) page 39 Excellent photo with three people for size comparison.
- ^ Earle, Christopher. "Gymnosperm Database - Cycadales". Retrieved November 24, 2021.
- ^ Corner, Prof. E.J.H. (1966). Natural History of Palms. Berkeley, Calif.: Univ. Calif. Press. p. 289.
- ^ Britton, Nathan L.; Rose, Joseph N. (1963). The Cactaceae - Volume 3 (reprint ed.). New York: Dover Pubs. Inc. p. 170.
- ^ Esterhuyse, Neels; et al. (2001). Remarkable Trees of South Africa. Pretoria: Briza Pubs. pp. 6 (table) and 156 & 159.
- ^ Claassen, Isabel (February 1987). "A Saad Semi-human Succulent". South African Panarama. 32 (2): 24.
- ^ Hodel, Donald R. (July 1993). "Growth of Some Palms in Tahiti". Principes. 37 (3): 376–378.
- ^ Wickens, G. E.; Pat Lowe (2008). The Baobabs: Pachycauls of Africa, Madagascar and Australia. Springer. pp. 139–140. ISBN 978-1-4020-6430-2.
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