T H U 



T H U 



THOROW-WAX. SeeBuptEURUM. 



THUJA, a genus containing a plant of the 

 hardy evergreen tree kind. 



It belongs to the class and order Montvcia 

 Monadelphia, and ranks in the natural order of 

 Conifer ce. 



The characters are : that in the male flower 

 the calyx is an ovate anient, composed of a 

 common rachis, on which opposite flowers are 

 placed in a triple opposition : each flower has 

 for its base a subovate, concave, obtuse scale : 

 there is no corolla : the stamina have four fila- 

 ments (in each floret) scarcely manifest: anthers 

 as many, fastened to the base of the calycine 

 scale : — female flower on the same plant : the 

 calyx is a common subovate strobile, surrounded 

 with opposite florets; composed of two-flowered, 

 ovate, convex scales, converging longitudinally : 

 there is no corolla: the pistillum is a very small 

 germ : style awl-shaped : stigma simple : the 

 pericarpium is an ovate-oblong strobile, obtuse, 

 opening longitudinally, with oblong scales, al- 

 most equal, convex outwardly, obtuse: the seeds 

 oblong, girt longitudinally with a membrana- 

 ceous wing, emarginate. 



The species cultivated are: 1. T. oeciden talis, 

 American Arbor-vitae; 2. T. orientalis, Chinese 

 Arbor-vitae. 



The first has a strong woody trunk, which 

 rises to the height of forty feet or more : the 

 bark, while young, is smooth and of a dark 

 brown colour, but as the trees advance the bark 

 becomes cracked, and less smooth : the branches 

 are produced irregularly on every side, standing 

 almost horizontal, and the young slender shoots 

 frequently hang down: these branches stand but 

 thin, and the vounger branches only have leaves, 

 so that when the trees are grown large they 

 make but an indifferent appearance, being so 

 thinly clothed with the leaves : the young 

 branches are flat, and the small leaves are placed 

 over each other like the scales of fish : the flow- 

 ers are produced from the side of the young 

 branches, pretty near to the footstalk : the 

 males grow in oblong catkins, and between 

 these the females are collected in form of cones. 

 When the former have shed their farina, they 

 soon drop off; but the latter are succeeded by 

 oblong cones, or strobiles, having obtuse smooth 

 scales, containing one or two oblong seeds. It 

 is a native of Siberia and Canada, where it is 

 very plentiful, but not much further south. 



There are different varieties ; as the American 

 Sweet-scented, and Variegated-leaved. 



The second species has the branches growing 

 closer together, and much more adorned with 

 leaves, which are of a brighter green colour, and 



make a much better appearance than the formers 

 the branches cross each other at right angles t 

 the leaves are flat, but the single divisions are 

 slender, and the scales smaller, and lie closer 

 over each other than those of the first sort : the 

 cones (strobiles) are also much larger, of a 

 beautiful gray colour, and their scales end in 

 acute reflexed points. It is a native of China 

 and Japan. 



Culture. — These plants may be increased by 

 seeds, layers, and cuttings. 



Good seeds should be obtained and be sown 

 soon after they are ripe, or as soon as they can 

 be obtained, in autumn or spring, in pots or 

 boxes of light earth, covering them half an inch 

 deep, placing the pots, Sec. in a sheltered warm 

 situation, or under the shelter of a frame in bad 

 weather, especially when sown in autumn, that 

 they may he protected from severe frosts : they 

 sometimes come up in the spring, but are fre- 

 quently apt to remain in the ground till the se- 

 cond year. When the plants are come up, the 

 pots should be placed in an east border to have 

 only the morning sun, but open to the free air, 

 giving frequent but very moderate waterings all 

 the summer ; and in winter removing the pots 

 again to a sheltered place till spring, when they 

 may be pricked out in nursery-rows ; or, when 

 they are small and weakly, continued in the 

 pots another year, placing them in a shady si- 

 tuation during summer, and in a sheltered place 

 in winter; and in spring following planting 

 them out in the nursery, in rows a foot or two 

 asunder, to remain to acquire size and strength 

 for planting out where they are to remain. 



The layers should be made from the young 

 shoots of one or two years growth, which may 

 be laid down early in autumn, bending down 

 the branches to the earth, and laying all the 

 young wood in by slit- or twist-laying, with 

 the tops only appearing a little above ground ; 

 shortening any that have much longer tops 

 than the others : they mostly emit roots in 

 the earth, and form proper plants by autumn 

 following; when, or rather in spring after, they 

 shouldbeseparated from the stools, andbe planted 

 in nursery-rows, to remain two or three years, 

 or till of a proper size for the shrubbery, &c. 



The cuttings should be made from the strong 

 young shoots of the same year's growth, which 

 should be planted in the autumn, in a shady 

 border, taking the opportunity of showery 

 weather, if possible, for the business : tliey 

 should be cut off with a small part of the old 

 wood, where practicable, and be planted in rows 

 a foot asunder, closing the earth well about 

 them : they will be properly rooted in one year 



