Torreya

Trees dioecious. Bark brown to grayish brown, tinged with orange, fissured. Branches spreading to drooping; twigs nearly opposite. Leaves mostly appearing 2-ranked, rigid; stomates abaxial, in 2 narrow, glaucous, whitish or brownish bands; apex sharp-pointed, spine-tipped, sharp to touch; resin canal central. Pollen cones ovoid or oblong, with 6–8 whorls of 4 sporophylls, each bearing 4 sporangia. Ovules 2, only 1 of each pair maturing. Seed maturing in 2 years; aril green or green with purple streaks, resinous, leathery, thin, completely enclosing woody seed coat, splitting into 2 parts at maturity; albumen ruminate. x = 11.

Distribution

North America, Asia in China and Japan.

Discussion

Two Asian species are planted as ornamentals in North America: Torreya nucifera Siebold & Zuccarini (kaya-nut, Japanese torreya), which yields edible seeds and cooking oil, and T. grandis Fortune (Chinese torreya).

Species 4(–6) (2 in the flora).

Selected References

Buchholz, J. T. 1940. The embryogeny of Torreya, with a note on Austrotaxus. Bull. Torrey Bot. Club 67: 731--754.

Burke, J. G. 1975. Human use of the California nutmeg tree, Torreya californica, and of other members of the genus. Econ. Bot. 29: 127--139.

Lower Taxa

Torreya californica, Torreya taxifolia

Key

1	Two-year-old branches reddish brown; leaves 3-8 cm, flattened on adaxial side, with 2 deeply impressed, glaucous bands of stomates abaxially, emitting pungent odor when crushed; aril light green streaked with purple; California.	Torreya californica
1	Two-year-old branches yellowish green, yellowish brown, or gray; leaves 1.5-3.8 cm, rounded on adaxial side, with 2 scarcely impressed, grayish bands of stomates abaxially, emitting fetid odor when crushed; aril dark green streaked with purple; Florida, Georgia.	Torreya taxifolia