subject: Cupressus - Small-sized Plastic Molding Machine - Plastic Injection Machine Manufacturer [print this page] Species Species
The number of species recognised within this genus varies sharply, from 16 to 25 or more according to the authority followed. This is because most populations are small and isolated, and it is difficult to be sure whether they should be accorded specific, subspecific or varietal rank. Current tendencies are to reduce the number of recognised species; when a narrow species concept is adopted, the varieties indented in the list below may also be accepted as distinct species. See also the New World species (below) for a likely split in the genus in the future.
Old World species
The Old World cypresses tend to have cones with more scales (8-14 scales, rarely 6 in C. funebris), each scale with a short broad ridge, not a spike. Cupressus sempervirens is the type species of the genus, defining the name Cupressus.
The New World cypresses tend to have cones with fewer scales (4-8 scales, rarely more in C. macrocarpa), each scale with an often prominent narrow spike. Recent genetic evidence (Little et al., November 2004) shows that they are less closely related to the Old World cypresses than previously thought, being more closely related to Callitropsis and Juniperus than to the rest of Cupressus. These species have very recently (Little 2006) been transferred to Callitropsis. New World species are found in marginal habitats with xeric soils, and therefore exhibit a fragmented allopatric pattern of distribution. This type of distribution results in disproportionate local abundance with most species restricted to small neighboring populations (Little 2006).
Cupressus abramsiana (Cupressus goveniana var. abramsiana; Callitropsis abramsiana; Santa Cruz Cypress)
Callitropsis nootkatensis (Nootka Cypress) is also sometimes treated as Cupressus nootkatensis
References
Farjon, A. (2005). Monograph of Cupressaceae and Sciadopitys. Royal Botanic Gardens, Kew. ISBN 1-84246-068-4.
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: 10441057. Available online.
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): 18721881. Abstract
Little, D. P. (2006). Evolution and circumscription of the true Cypresses. Syst. Bot. 31 (3): 461-480.
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