''Hesperocyparis macnabiana'' (MacNab cypress or Shasta cypress) is a species of

western cypress ''Hesperocyparis'' (western cypress) is a genus of trees in the family Cupressaceae, containing North American species otherwise assigned to the genus ''Cupressus''. They are found throughout western North America. Only a few species have wide ra ...

in from California that was previously named ''Cupressus macnabiana''.

Distribution

''Hesperocyparis macnabiana'' is

endemic Endemism is the state of a species being found only in a single defined geographic location, such as an island, state, nation, country or other defined zone; organisms that are indigenous to a place are not endemic to it if they are also foun ...

to northern

California California () is a U.S. state, state in the Western United States that lies on the West Coast of the United States, Pacific Coast. It borders Oregon to the north, Nevada and Arizona to the east, and shares Mexico–United States border, an ...

. ''Hesperocyparis macnabiana'' is one of the most widely distributed of all the native California cypresses, found growing in

chaparral Chaparral ( ) is a shrubland plant plant community, community found primarily in California, southern Oregon, and northern Baja California. It is shaped by a Mediterranean climate (mild wet winters and hot dry summers) and infrequent, high-intens ...

, oak woodlands, and coniferous woodlands

habitat In ecology, habitat refers to the array of resources, biotic factors that are present in an area, such as to support the survival and reproduction of a particular species. A species' habitat can be seen as the physical manifestation of its ...

s along the inner northern

California Coast Ranges The Coast Ranges of California span from Del Norte County, California, Del Norte or Humboldt County, California, south to Santa Barbara County, California, Santa Barbara County. The other three coastal California mountain ranges are the Trans ...

and the foothills of the northern

Sierra Nevada The Sierra Nevada ( ) is a mountain range in the Western United States, between the Central Valley of California and the Great Basin. The vast majority of the range lies in the state of California, although the Carson Range spur lies primari ...

. MacNab cypress is often associated with ultramafic soils.

Description

''Hesperocyparis macnabiana'' is an

evergreen In botany, an evergreen is a plant which has Leaf, foliage that remains green and functional throughout the year. This contrasts with deciduous plants, which lose their foliage completely during the winter or dry season. Consisting of many diffe ...

shrub A shrub or bush is a small to medium-sized perennial woody plant. Unlike herbaceous plants, shrubs have persistent woody stems above the ground. Shrubs can be either deciduous or evergreen. They are distinguished from trees by their multiple ...

or small

tree In botany, a tree is a perennial plant with an elongated stem, or trunk, usually supporting branches and leaves. In some usages, the definition of a tree may be narrower, e.g., including only woody plants with secondary growth, only ...

, (rarely to ) 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. The

leaves A leaf (: leaves) is a principal appendage of the stem of a vascular plant, usually borne laterally above ground and specialized for photosynthesis. Leaves are collectively called foliage, as in "autumn foliage", while the leaves, stem, ...

are scale-like, 1–2 mm long with an acute apex, and a conspicuous white

resin A resin is a solid or highly viscous liquid that can be converted into a polymer. Resins may be biological or synthetic in origin, but are typically harvested from plants. Resins are mixtures of organic compounds, predominantly terpenes. Commo ...

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.Flora of North America: ''Cupressus macnabiana''
/ref> The

seed cones A conifer cone, or in formal botanical usage a strobilus, : strobili, is a seed-bearing organ on gymnosperm plants, especially in conifers and cycads. They are usually woody and variously conic, cylindrical, ovoid, to globular, and have scales ...

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 by

wildfire A wildfire, forest fire, or a bushfire is an unplanned and uncontrolled fire in an area of Combustibility and flammability, combustible vegetation. Depending on the type of vegetation present, a wildfire may be more specifically identified as a ...

. This enables heavy seed release to colonize the bare, fire-cleared ground. The

pollen Pollen is a powdery substance produced by most types of flowers of seed plants for the purpose of sexual reproduction. It consists of pollen grains (highly reduced Gametophyte#Heterospory, microgametophytes), which produce male gametes (sperm ...

cones are 3–4 mm long, and release their pollen in the fall.

Taxonomy

''Hesperocyparis macnabiana'' was given its first scientific description in 1855 by the naturalist Andrew Murray under the name ''Cupressus macnabiana''. It was named after William Ramsay McNab of the

Royal Botanic Garden Edinburgh The Royal Botanic Garden Edinburgh (RBGE) is a scientific centre for the study of plants, their diversity and conservation, as well as a popular tourist attraction. Founded in 1670 as a physic garden to grow medicinal plants, today it occupies ...

the suggestion of Murray's brother, William Murray. As part of spiting the new world cypress species into the new genus ''

Hesperocyparis ''Hesperocyparis'' (western cypress) is a genus of trees in the family Cupressaceae, containing North American species otherwise assigned to the genus ''Cupressus''. They are found throughout western North America. Only a few species have wide ra ...

'' it was moved out of ''

Cupressus ''Cupressus'' (common name cypress) is one of several genus, genera of evergreen conifers within the Family (biology), family Cupressaceae; for the others, see cypress. It is considered a Polyphyly, polyphyletic group. Based on genetic and morpho ...

'' by Jim A. Bartel in 2009. This split has not been universally accepted, but as of 2024

Plants of the World Online Plants of the World Online (POWO) is an online taxonomic database published by the Royal Botanic Gardens, Kew. History Following the Convention on Biological Diversity, the Royal Botanic Gardens in Kew launched Plants of the World Online i ...

(POWO) and

World Flora Online World Flora Online is an Internet-based compendium of the world's plant species. Description The World Flora Online (WFO) is an open-access database, launched in October 2012 as a follow-up project to The Plant List, with the aim of publishi ...

(WFO) both list the new classification as accepted.

References

* * *Wolf, C. B. & Wagener, W. E. (1948). The New World cypresses. El Aliso 1: 195-205.

External links

Gymnosperm Database: ''Cupressus macnabiana''Jepson Flora Project: ''Cupressus macnabiana''
{{Taxonbar, from=Q1144379 macnabiana Endemic flora of California Flora of the Sierra Nevada (United States) Trees of Northern America Natural history of the California chaparral and woodlands Natural history of the California Coast Ranges Plants described in 1855

Distribution

Description

Taxonomy

See also

References

External links