Small, evergreen trees with flat, 2-ranked, fan-like spray and closely overlapping, small, appressed leaves of two shapes on different branchlets, one awl-shaped and acute, the other scale-like, usually blunt and close to the branch. Fertile catkins of few, overlapping scales fixed by the base; at maturity, dry and spreading. There are scores of named varieties of Arbor-vitae sold by the nurserymen under 3 different generic names, Thuya, Biota, and Thuyopsis. There are but slight differences in these groups, and they will in this work be placed together under Thuya. Some that in popular language might well be called Arbor-vitæ (the Retinosporas) will, because of the character of the fruit, be included in the next genus. * Scales of the cones pointless, thin, straight. (Thuya) 1, 2. * Scales reflexed and wedge-shaped. (Thuyopsis) 3. * Scales thick, with horn-like tips. (Biota) 4. [Illustration: T. occidentàlis.] 1. =Thùya occidentàlis=, L. (AMERICAN ARBOR-VITÆ. WHITE CEDAR.) Leaves in 4 rows on the 2-edged branchlets, having a strong aromatic odor when bruised. Cones oblong, 1/3 in. long, with few (6 to 10) pointless scales. A small tree, 20 to 50 ft. high, or in cultivation 1 to 50 ft. high, with pale, shreddy bark, and light, soft, but very durable wood. Wild north, and extensively cultivated throughout under more than a score of named varieties. Their names--_alba_, _aurea_, _glauca_, _conica_, _globosa_, _pyramidalis_, _pendula_, etc.--will give some idea of the variations in color, form, etc. [Illustration: T. gigantèa.] 2. =Thùya gigantèa=, Nutt. (GIANT ARBOR-VITÆ.) Leaves scale-shaped, somewhat 4-sided, closely overlapping, sharp-pointed, slightly tuberculate on the back; cones more or less clustered and nearly ½ in. long. A very large and graceful tree, 200 ft. high, with white, soft wood; from the Pacific coast; introduced but not very successfully grown in the Atlantic States. [Illustration: T. dolabràta.] 3. =Thùya dolabràta=, L. (HATCHET-LEAVED ARBOR-VITÆ.) Leaves large, sometimes ¼ in. long, very blunt, in 4 rows on the flattened spray. Cones quite small, ovate, sessile, with jagged edges; scales reflexed and wedge-form. A small conical tree with horizontal branches and drooping branchlets; which, because of its large leaves (for an Arbor-vitæ) and flexible branchlets, is quite unique and interesting. In shaded and moist places it has done quite well as far north as New York. [Illustration: T. orientàlis.] 4. =Thùya orientàlis=, L. (EASTERN OR CHINESE ARBOR-VITÆ.) Leaves small, in 4 opposite rows, appressed, acute, on the numerous 2-edged branchlets. Cones large, roundish, with thick leathery scales having recurving, horn-like tips. Of this species there are as many varieties sold as of number one, and nearly the same varietal names are used; but it is not so good a species for general cultivation in this country.