RAMIFICATION. 17 



of ^sorth America the intervals are strikingly uniform. The general 

 direction of the primary branches is horizontal, but the higher ones are 

 often more or less ascending, while the lower ones are deflexed by the 

 weight of their appendages. Very often single branches are produced 

 between the whorls, but these are adventitious, and their development is 

 generally much weaker than the others. 



Of the branches comprising a single whorl, it often happens that the 

 growth of one or two is more vigorous than that of the others ; a 

 rigorous uniformity of growth is the exception rather than the rule.* 

 In the remaining CONIFERS and in the TAXACE^E, the primary branches 

 are produced around the trunk, usually at close irregular intervals, 

 and their general direction is much the same as in the Abietineee 

 and Araucarineae ; but there are many exceptions, especially where the 

 disproportion between the stem and primary branches is not so marked. 

 The resulting habit from this mode of growth is, that so long as the 

 stem or main axis continues to ascend, the branches gradually decrease 

 in length from below upwards, and those trees that are furnished with 

 branches from the base have the outline of an elongated cone or spire. 



Among the Cupressinese and Taxaceae, and even among the true 

 Pines, instances occur in which the primary branches and their ramifica- 

 tions take an upward direction, either parallel with the principal axis, 

 or at a small angle to it ; the spire-like - habit then becomes modified 

 into the tapering or flame-like, the fastigiate, the globose, or even the 

 bush form. Well-known examples of the flame-like are afforded by the 

 Roman Cypress and the erect variety of Lawson's Cypress. The fastigiate 

 habit is seen in the Irish Yew, the Swedish Juniper, the upright form 

 of Cephalotaxus pedunculata, and others ; in these fastigiate forms of 

 Taxus and Cephalotaxus correlative changes are observable in the leaves 

 which do not become twisted at the base, and consequently not pseudo- 

 distichous. The globose habit is represented in gardens by varieties of 

 TJiuia orientalis, Cupressus obtusa, Juniperus cornmunis and others ; 

 and the bush form by Cephalotaxus, Saxe-gothsea, varieties of the 

 common Yew, many Junipers, several varieties of Cupressus obtusa, C. 

 pisifera, TJiuia occidentalis, etc. When the primary branches are short 

 and nearly of equal length from below upwards, the tree takes a 

 columnar form, such as is often seen .in Pinus Cembra and Cupressus 

 Lawsoniana, and always in Libocedrus decurrens in this country. In a 

 few Junipers, in one or two varieties of the common Yew, in a 

 remarkable variety of Cryptomeria japonica which originated in Japan, 

 in Thuia dolabrata Icetevirens introduced from the same country, and 

 in a few others, the principal axis fails to ascend, while the primary 

 branches and their ramifications spread over the surface of the ground. 

 This prostrate habit is one of the least common amongst the cultivated 

 Taxads and Conifers, but at high altitudes and at the extreme northern 

 limit of arborescent vegetation where the annual periods of growth are 

 short and the temperature low, the prostrate habit is common to well 

 nigh all the species found under those conditions. 



Much variation exists in the amount of branching. In Arauearia 

 imbricata, A. Bidwillii, A. brasiliensis, A. Gookii and probably other 

 species, often conspicuously in the first named,! also in some of the 



*It is most frequent in the Araucarias and some of the Abies during the early period of their life, 

 t Primary brandies of Arauearia imbricata have been noted by the author 710 feet 

 long without a single lateral shoot. 



