328 



DESCRIPTIONS OF THIO SHRUBS 



an arrangement that is called 2-ranked. The cones are short, under 1 inch, 

 pendulous with smooth scales, found at the tips of the branches. Of the 

 Common Hemlock — Tsuga canadensis, — Sakgent's Weeping Hemlock 

 (587) — var. Sargentiana, or Sargenti pendula — rarely grows over 3 feet 

 high and has short drooping branchlets forming a dense flat-topped mass 

 of foliage; Dwarf Hemlock — mina — is a dwarf with spreading branches 

 and short branchlets forming a depressed shrub under 3 feet high. There 

 is also a variety n^na of the Japanese Hemlock, Tsuga Si^boldi. The 

 latter can be separated from the common American one by a close exami- 

 nation of the leaves with a lens ; the edge of the American is somewhat 

 notched, while the Japanese is entire. [ Seeds ; twig cuttings ; grafting.] 



Fig. 59o. — Juniper-leaved 

 Arborvitae. 



Fig. 594. — Silver Retinospora. 



Thuja and Chamaecyparis. The Arborvit?e group of evergreens are 

 among the most difficult class of plants to classify. The greatest confu- 

 sion of names both common and scientific occurs with reference to them 

 in books and catalogues. They have two very distinct forms of leaves ; 

 these are properly called the "juvenile" and the "adult." All of this 

 group have opposite sessile leaves ; but the seedlings begin with linear 

 spreading ones about a half inch long ; these are the juvenile leaves ; later 

 these change to scale-shaped leaves, appressed to and completely covering 

 the stems, the adult leaves. Some of the bushy forms, the only ones 



