Cupressaceae
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The Cupressaceae or cypress family is a conifer family of cosmopolitan distribution. The family includes 27 to 30 genera (17 monotypic) with about 130-140 species. They are monoecious or (rarely) dioecious trees and shrubs from 1-112m (3-367 ft) tall. The bark of mature trees is commonly orange- to red- brown and of stringy texture, often flaking or peeling in vertical strips, but smooth, scaly or hard and square-cracked in some species.
The leaves are arranged either spirally, in decussate pairs (opposite pairs, each pair at 90° to the previous pair) or in decussate whorls of 3 or 4, depending on the genus. On young plants, the leaves are needle-like, becoming small and scale-like on mature plants of many (but not all) genera; some genera and species retain needle-like leaves throughout their life. Old leaves are mostly not shed individually, but in small sprays of foliage (cladoptosis); exceptions are the leaves on shoots which develop into branches, which eventually fall off individually when the bark starts to flake. Most are evergreen with the leaves persisting 2-10 years, but three genera (Glyptostrobus, Metasequoia, Taxodium) are deciduous or include deciduous species.
The cones are either woody, leathery, or (in Juniperus) berry-like and fleshy, with one to several ovules per scale. As with the foliage, the cone scales are arranged spirally, decussate (opposite) or whorled, depending on the genus. Seedlings usually have two cotyledons, but in some species up to six.
Cupressaceae is the most widely distributed conifer family, with a near-global range in all continents except for Antarctica, stretching from 71°N in arctic Norway (Juniperus communis) south to 55°S in southernmost Chile (Pilgerodendron uviferum), while Juniperus indica reaches 5200 m altitude in Tibet, the highest altitude reported for any woody plant.
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Classification
Cupressaceae.PNG
The family Cupressaceae is now widely regarded as including the Taxodiaceae, previously treated as a distinct family, but now shown not to differ from the Cupressaceae in any consistent characteristics. The one exception in the former Taxodiaceae is the genus Sciadopitys, which is genetically distinct from the rest of the Cupressaceae, and is now treated in its own family, Sciadopityaceae.
The family Cupressaceae is divided into seven subfamilies, based on genetic analysis:
- Cunninghamioideae: Cunninghamia
- Athrotaxidoideae: Athrotaxis
- Taiwanioideae: Taiwania
- Sequoioideae: Sequoia, Sequoiadendron, Metasequoia
- Taxodioideae: Taxodium, Glyptostrobus, Cryptomeria
- Callitroideae: Callitris, Actinostrobus, Neocallitropsis, Widdringtonia, Diselma, Fitzroya, Austrocedrus, Libocedrus, Pilgerodendron, Papuacedrus
- Cupressoideae: Thuja, Thujopsis, Chamaecyparis, Fokienia, Calocedrus, Tetraclinis, Microbiota, Platycladus, Callitropsis, Cupressus, Juniperus
Superlatives
The family is notable for including the largest, tallest, and stoutest individual trees in the world, and also the second longest lived species in the world:
Largest - Giant Sequoia
Tallest - Coast Redwood
Stoutest - Montezuma Cypress
Second oldest - Alerce (after Great Basin Bristlecone Pine)
Uses
Many of the species are important timber sources, especially in the genera Chamaecyparis, Cryptomeria, Cunninghamia, Cupressus, Sequoia and Thuja. Many are also of great importance in horticulture, most notably Lawson's Cypress, several junipers and the infamous hybrid Leyland Cypress.
References
- Farjon, A. 1998. World Checklist and Bibliography of Conifers. Royal Botanic Gardens, Kew. 300 p. ISBN 1-900347-54-7.
- Gadek, P. A., Alpers, D. L., Heslewood, M. M., & Quinn, C. J. 2000. Relationships within Cupressaceae sensu lato: a combined morphological and molecular approach. American Journal of Botany 87: 1044–1057. Abstract (http://www.amjbot.org/cgi/content/abstract/87/7/1044)
- Farjon, A., Hiep, N. T., Harder, D. K., Loc, P. K., & Averyanov, L. 2002. A new genus and species in the Cupressaceae (Coniferales) from northern Vietnam, Xanthocyparis vietnamensis. Novon 12: 179–189.
- Little, D. P., Schwarzbach, A. E., Adams, R. P. & Hsieh, Chang-Fu. 2004. The circumscription and phylogenetic relationships of Callitropsis and the newly described genus Xanthocyparis (Cupressaceae). American Journal of Botany 91 (11): 1872–1881. Abstract (http://www.amjbot.org/cgi/content/abstract/91/11/1872)
External links
- Arboretum de Villardebelle (http://www.pinetum.org/cones/mpfcones.htm) Cone images of many species
- Gymnosperm Database: Cupressaceae (http://www.botanik.uni-bonn.de/conifers/cu/index.htm)
- Flora of North America - Cupressaceae (http://flora.huh.harvard.edu:8080/flora/browse.do?flora_id=1&taxon_id=10237)
- Digital Flora of Texas (http://www.csdl.tamu.edu/FLORA/imaxxcup.htm) List of images of the Cupressaceae
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Links to other Pinophyta families |
| Pinaceae | Araucariaceae | Podocarpaceae | Sciadopityaceae | Cupressaceae | Cephalotaxaceae | Taxaceae |
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