Cupressus × notabilis / Alice Holt cypress
Cupressus × notabilis as described in 2009 by (A.F. Mitchell) James Eckenwalder in Conifers of the World, is a synthetic hybrid of Nootka cypress (C. nootkatensis) and Arizona cypress (C. arizonica var. glabra), commonly known as Alice Holt cypress. This cross originally took place at Leighton Hall in the United Kingdom. Two of the resulting seedlings were raised in 1957 and are under evaluation at the British Forestry Commission's Alice Holt Station, hence the common name. The species name, "notabilis" comes from the Latin language, meaning "notable."
Description. Alice Holt cypress is an evergreen conifer that grows to mature heights of 60 feet (18 m) tall with a trunk up to 18 inches (45 cm) in diameter, measured at breast height.
- Bark is thin, reddish to purplish brown in color, peeling in vertical lines or flakes.
- Crown is dense and irregular and broadly conical. Eckenwalder describes it as having a tattered appearance.
- Branching is gently arching. Branchlets are slightly flattened, measuring 0.04 to 0.06 inch (1 - 1.5 mm) wide.
- Scale leaves on branchlets are about 0.08 inch (2 mm) long, colored light gray-green.
- Pollen cones measure 0.1 to 0.14 inch (2.5 - 3.5 mm) long and 0.06 to 0.08 inch (1.5 - 2 mm) wide, with 5 to 7 pairs of pollen scales, each with 3 to 5 pollen sacs.
- Seed cones are spherical, measuring 0.48 inch (1.2 cm) long, colored purple-brown at maturity with a bluish white waxy coating. They are comprised of 3 to 4 pairs of seed scales, each with a flattened, triangular point on the face and lines radiating from that point.
- Seeds number 3 to 4 per scale, each measuring 0.16 to 0.2 inch (4 - 5 mm) long.
This conifer is only known to exist in cultivation. Given the great distance between the natural ranges of the parent plants, natural hybridization is likely never to have taken place.
Hardy to USDA Zone 7, cold hardiness limit between 0º to 10ºF (-17.7° and -12.2°C).