| Chamaecyparis Spach 1841Common NamesCypress (7, 11, 12), white-cedar, false-cypress, faux-cypres (4).Taxonomic notesFive to eight species depending on taxonomic opinion. Some authors include species of Chamaecyparis in the genus Cupressus (4), but genetic studies indicate they are not particularly closely related (5, 6). Two species included in this genus at various times, Ch. funebris and Ch. nootkatensis, are of disputed generic position; the former is now usually returned to Cupressus (7, 8), and recent evidence suggests the latter may soon also be transferred back there (9, 10); neither has been studied genetically yet. Two other taxa sometimes treated as species (Ch. henryae and Ch. taiwanensis) are usually treated as subspecies or varieties of Ch. thyoides and Ch. obtusa respectively. Cultivated juvenile forms of several species have been referred to the superfluous Retinospora Siebold & Zuccarini.DescriptionTall monoecious trees (rarely shrubs) of pyramidal habit, the bark smooth, peeling off in strips or scales or fissured into ridges. Leading shoots nodding, branches spreading, the branchlets dorsiventrally flattened, rarely (Ch. thyoides) more or less terete or rhombic in cross section, in fan-shaped or pinnately flattened sprays. Leaves opposite in 4 ranks. Juvenile leaves subulate. Mature leaves opposite, scale-like, lateral and facial pairs of differing shape, similar in size or the facial pairs smaller, and closely overlapping, ovate to rhombic, acuminate to obtuse, entire. Staminate cones ovoid to oblong, yellow or (usually) red, stamens decussate, with 2-3 pairs of sporophylls, each sporophyll with 2-4 pollen sacs. Ovulate cones maturing and opening in 6-8 months ([10-]17-19 months in Ch. nootkatensis only) from pollination, shed soon after seed release, globose to ovoid-globose, green or violet, often glaucous, maturing brown, 4-12(-14) mm; scales persistent, (2-)3-5(-6) pairs, peltate or basifixed (valvate in Ch. nootkatensis), thick and woody, the terminal pair fused (except in Ch. nootkatensis, where open with a central columella). Seeds (1)2-4(5) per scale, slightly compressed, with 2 equal, membranaceous wings. Cotyledons 2, rarely 3. x = 11 (2, 3, 4).RangeNorth America, Japan and Taiwan (2).Big TreeCh. formosensis.OldestPerhaps Ch. nootkatensis, with fairly reliable data indicating ages exceeding 1800 years, but few data are available on other species.DendrochronologyEthnobotanyThe genus is of immense importance to modern horticulture; two species (Ch. lawsoniana, Ch. pisifera) account for perhaps 80-90% of the ornamental conifers grown in British gardens.ObservationsRemarksName derived from the Greek: chamai = on the ground, and kyparissos = cypress (3).Several of the species show high variation in seedbeds, leading to the selection for horticultural use of many hundred cultivars. "Three [Ch. lawsoniana, Ch. pisifera, Ch. obtusa] are very variable and have given rise to a ridiculous flood of selected seedlings and mutations, many of which are so similar to others as to be just not worth perpetuating. Unfortunately this flow still continues. Very great restraint should now be exercised in introducing fresh forms that will add more names to our listings but no more beauty to our gardens" (11). This exasperated remark is followed by a 57 page list of Chamaecyparis cultivar names, including 29 pages with 559 names in Ch. lawsoniana alone - no wonder!. Citations(1) Silba 1986.(2) Li 1975. (3) Walker 1976. (4) David C. Michener at the Flora of North America web site. (5) Gadek & Quinn 1993. (6) S.J. Brunsfeld et al. 1994. Phylogenetic relationships among the genera of Taxodiaceae and Cupressaceae: Evidence from rbcL sequences. Systematic Botany 19: 253-262. (7) Rushforth 1987. (8) Farjon 1998. (9) H.J. Welch. 1991. The Conifer Manual vol. 1. (10) M.P. Frankis 1993. Nootka Cypress: Chamaecyparis or Cupressus? Conif. Soc. Austral. Newsletter 12: 9-10. (11) H.J. Welch & G. Haddow 1993. The World Checklist of Conifers. This page co-edited with M.P. Frankis, Feb-1999. | |
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