Torreya californica

Scientific name: Torreya californica J. Torrey 1854

Synonyms: Caryotaxus myristica (Hook.) Henkel & W.Hochst., Foetataxus myristica (Hook.) J.Nelson, Torreya myristica Hook., Tumion californicum (Torr.) Greene, Tumion californicum var. littoralis Lemmon

Common names: California nutmeg, California torreya, Stinking cedar

Description

Tree to 20(-30) m tall, with trunk to 1(-2) m in diameter, or a shrub under 4 m in chaparral. Bark gray, deeply furrowed between narrow, interlacing, flat-topped ridges. Crown conical, dense, and very regular in youth, becoming more dome-shaped and irregular with age, with closely spaced, upwardly angled to more nearly horizontal branches bearing pairs of upwardly angled, horizontal or drooping branchlets fairly densely clothed with nonoverlapping foliage. Twigs passing from yellowish green through tan to reddish brown in their second, third, or fourth year. Leaves pungently aromatic when crushed, 3-5(-8) cm long, 1.5-2.5(-3) mm wide, very stiff, dark green to bluish green and flat around the midrib above, with indented white or yellowish green stomatal bands beneath. Individual needles straight or slightly curved, widest before the middle, tapering gradually and then more abruptly to the roundly triangular tip with a sharp point 0.5-1.2 mm long, and more abruptly to the rounded base on a very short petiole 2-3 mm long. Pollen cones white or pale yellow, about 7-10 mm long and 3.5-5 mm across. Seeds with aril pale green to whitish green streaked with purple, 2.5-3.5 cm long and 2-3 cm in diameter. Female gametophyte tissue inside the shiny yellowish brown stony layer deeply to only slightly wrinkled.

Scattered in the Coast Ranges and on the western slopes of the Sierra Nevada of central California. Scattered or forming small groves in mixed riparian evergreen and deciduous montane forests along streamsides and in chaparral shrublands on slopes; (100-)500-1,800(-2,500) m.

Conservation Status

Red List Category & Criteria: Vulnerable

Past logging has virtually eliminated Torreya californica from parts of its historic range and also removed most of the large trees across almost all of its range. Regrowth is reported to be very slow. On this basis a past decline of more than 50% of mature trees in the population has been inferred over the past 150 years (three generations), leading to an assessment of Vulnerable under the A1 criterion.

Populations are usually small and localized. The population is substantially reduced from what it was before but is now slowly recovering.

Torreya californica is a scattered understorey tree usually growing in moist and shady places in hilly to mountainous terrain dominated by tall conifers, especially Sequoia sempervirens, Picea sitchensis and Pseudotsuga menziesii. In the western valleys of the Sierra Nevada it is associated with angiosperms, mainly Acer spp., Cornus nuttallii, Platanus occidentalis, and Alnus rubra and here it strictly adheres to stream banks in steep canyons at altitudes around 1,200 m a.s.l. Its altitudinal range is from near sea level (but usually above 200 m) in the Coast Ranges to 2,500 m a.s.l. in the Sierra Nevada. On serpentine rock it becomes a stunted tree or shrub and occurs on north-facing slopes in coastal chaparral. It is capable of resprouting following disturbance such as fire although regrowth is slow.

Logging in the late 19th and up to the mid 20th centuries virtually eliminated California nutmeg from the Vaca Mountains of Napa and Solano counties, and considerably reduced populations in the Santa Cruz Mountains and lower Russian River area of Sonoma County (Howard 1992). Logging also eliminated many of the larger trees in the remainder of its range and resulted in a decline of mature trees in the total population, which is only now slowly being restored. As this species is dependent on forest cover, deforestation in parts of California has further contributed to a decline. On this basis it is reasonable to infer an historic decline in the number of mature trees of at least 50%. This decline has now ceased or virtually ceased.

In the past, Torreya californica was used for cabinet making, fencing and bridges, as it is rot resistant. Due to its current rarity it is no longer used. California Indians used it for their bows, seeds were roasted for food and some tribes (e.g. the Pomo) used the roots for basket weaving. Torreya californica is the most commonly cultivated species of its genus and can grow into an impressive, wide crowned tree with striking foliage and large, pendulous, plum-like green or glaucous seeds. It is almost exclusively used as an ornamental in large gardens or planted in arboreta. The name 'nutmeg' only refers to a superficial similarity with true nutmeg fruits (from Myristica fragrans, an angiosperm tree species). Although California nutmeg has been in cultivation as a handsome, symmetrical evergreen since its botanical description and naming by John Torrey in the 1850s, it is not commonly planted and only a few cultivars have been selected and propagated over the years.

This species is known from several protected areas within its range.

References

Farjon, A. (2010). A Handbook of the World's Conifers. Koninklijke Brill, Leiden.
Eckenwalder, J.E. (2009) Conifers of the World: The Complete Reference. Timber Press, Portland.
IUCN Red List of Threatened Species, International Union for Conservation of Nature and Natural Resources. Cambridge, UK /Gland, Switzerland

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