| Hesperocyparis macnabiana | |
|---|---|
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| Hesperocyparis macnabiana foliage | |
Scientific classification | |
| Kingdom: | Plantae |
| Clade: | Tracheophytes |
| Clade: | Gymnospermae |
| Division: | Pinophyta |
| Class: | Pinopsida |
| Order: | Cupressales |
| Family: | Cupressaceae |
| Genus: | Hesperocyparis |
| Species: | H. macnabiana |
| Binomial name | |
| Hesperocyparis macnabiana (A.Murray bis) Bartel | |
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| Natural range | |
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| (Red circles indicate extinct populations.) | |
| Synonyms[3] | |
List
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Hesperocyparis macnabiana (MacNab cypress orShasta cypress) is a species ofwestern cypress in from California that was previously namedCupressus macnabiana.[4]
Hesperocyparis macnabiana isendemic to northernCalifornia.Hesperocyparis macnabiana is one of the most widely distributed of all the native California cypresses, found growing inchaparral,oak woodlands, and coniferous woodlandshabitats along the inner northernCalifornia Coast Ranges and the foothills of the northernSierra Nevada. MacNab cypress is often associated with ultramafic soils.[5]
Hesperocyparis macnabiana is anevergreenshrub or smalltree, 3–12 metres (9.8–39.4 ft) (rarely to 17 metres (56 ft)) tall, with a spreading crown that is often broader than it is tall. The foliage is produced in dense, short flat sprays (unlike most other California cypresses, which do not have flattened sprays), bright glaucous gray-green, with a strong spicy-resinous scent. Theleaves are scale-like, 1–2 mm long with an acute apex, and a conspicuous whiteresin gland on the center of the leaf. Young seedlings produce needle-like leaves up to 10 mm (0.4 inches) long in their first year.[6]
Theseed cones are oblong-ovoid to cuboid, 15–25 mm long and 13–20 mm broad, with six (rarely four or eight) scales, each scale bearing a prominent umbo; they are strongly serotinous, not opening to release the seeds until the parent tree is killed bywildfire. This enables heavy seed release to colonize the bare, fire-cleared ground. Thepollen cones are 3–4 mm long, and release their pollen in the fall.[6]
Hesperocyparis macnabiana was given its first scientific description in 1855 by the naturalistAndrew Murray under the nameCupressus macnabiana.[3] It was named afterWilliam Ramsay McNab of theRoyal Botanic Garden Edinburgh the suggestion of Murray's brother, William Murray.[7] As part of spiting the new world cypress species into the new genusHesperocyparis it was moved out ofCupressus by Jim A. Bartel in 2009.[3] This split has not been universally accepted,[8] but as of 2024Plants of the World Online (POWO) andWorld Flora Online (WFO) both list the new classification as accepted.[3][9]
