Cupressus abramsiana
From Wikipedia, the free encyclopedia
 |
||||||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
|
|
||||||||||||||
| Scientific classification | ||||||||||||||
|
||||||||||||||
|
|
||||||||||||||
| Cupressus abramsiana C.B.Wolf |
Cupressus abramsiana (Santa Cruz Cypress) is a taxon of disputed status in the genus Cupressus endemic to the Santa Cruz Mountains of Santa Cruz and San Mateo Counties in west-central California.
When cypresses were discovered in the Santa Cruz Mountains in 1881, they were first identified as Cupressus goveniana, but Jepson (1909) considered them to be Cupressus sargentii. In a detailed analysis, Wolf (1948) concluded it was a distinct species, naming it after L. R. Abrams, Emeritus Professor of Botany at Stanford University[1].
Subsequent authors have either followed Wolf in treating it as a species (Griffin & Critchfield 1976[2], the 1993 edition of the Jepson Manual[3], and Lanner 1999[4]), or within Cupressus goveniana as either a variety (Cupressus goveniana var. abramsiana (C.B.Wolf) Little; as in Little (1970)[5], the Gymnosperm Database[6] and Farjon (2005)[7]), or not distinguished at all within C. goveniana (Flora of North America[8]). It has also recently been transferred in one study (along with the other New World species of Cupressus) to the genus Callitropsis, as Callitropsis abramsiana (C.B.Wolf) D. P. Little[9].
Santa Cruz Cypress is a small evergreen tree growing to 10 m (rarely to 25 m) tall. The bark is gray, with a fibrous stringy texture, shredding on old trees. The foliage is bright green to yellowish-green, with scale-like leaves 1-1.5 mm long, the leaf tips slightly spreading on vigorous shoots but not on small shoots. Seedlings bear needle-like leaves 8-10 mm long. The cones are ovoid, 20-30 mm long and 15-22 mm broad, with eight or ten scales arranged in opposite decussate pairs, with the bract visible as no more than a small lump or short spine on the scale. The seeds are 3-5 mm long, glaucous brown, with a pair of small wings along the sides[1]. The cones remain closed on the trees for many years, until the trees are killed by a forest fire; after the tree is dead, the cones open to release the seeds which can then germinate successfully on the bare fire-cleared ground[4].
It is in some respects intermediate between Cupressus goveniana and Cupressus sargentii in morphology, and two studies have suggested (without conclusive proof) that it could be a natural hybrid between the two[10][11].
It is rare in the wild, found in only five small localities, and is listed as endangered[4][12]. It is separated from Cupressus goveniana in Monterey County by a gap of about 50 km, and from the also closely related Cupressus pigmaea by a gap of about 200 km[2]. It grows at 460-1200 m altitude, much higher than either C. goveniana or C. pigmaea[7].
[edit] References
- ^ a b Wolf, C. B. & Wagener, W. E. (1948). The New World Cypresses. El Aliso 1: 215-222.
- ^ a b Griffin, J. R., & Critchfield, W. B. (1976). The Distribution of Forest Trees in California. USDA Forest Service Research Paper PSW-82.
- ^ Cupressus abramsiana in the Jepson Manual, University of California Press (1993)
- ^ a b c Lanner, R. M. (1999). Conifers of California. Cachuma Press. ISBN 0-9628505-3-5
- ^ Little, E. L. (1970). Names of New World Cypresses (Cupressus). Phytologia 20: 429-445.
- ^ Gymnosperm Database
- ^ a b Farjon, A. (2005). A Monograph of Cupressaceae and Sciadopityaceae. Royal Botanic Gardens, Kew. ISBN 1-84246-068-4.
- ^ Eckenwalder, J. E., in Flora of North America
- ^ Little, D. P. (2006). Evolution and circumscription of the true Cypresses. Syst. Bot. 31 (3): 461-480.
- ^ McMillan, C. (1951). A third locality for Cupressus abramsiana Wolf. Madroño 11: 189-194.
- ^ Zavarin, E., Lawrence, L., & Thomas, M. C. (1971). Compositional variations of leaf monoterpenes in Cupressus macrocarpa, C. pygmaea, C. goveniana, C. abramsiana and C. sargentii. Phytochemistry 10: 379-393.
- ^ IUCN status report.
