32 



JOURNAL OF THE ROYAL HORTICULTURAL SOCIETY; 



popular plants in common use, is always an irritating incoil- 

 venience, but when the inevitable occurs the best course is to 

 accept it. For the nonce let us call this group of Conifers 

 Eetinosporas, and, numerous as they are, they have all been 

 derived from two, and only two, types or species, so surprisingly 

 polymorphous have these species proved under Japanese cultiva- 

 tion. The two species are obtiisa and insifera, and the numerous 

 varieties of Retinospora naturally fall into two groups, of which 

 these two species are the types. In its native country B. obtusa 

 is a lofty tree, often attaining a height of 150 feet where the 

 annual rainfall is greatest ; B. pisif era is a much smaller tree. In 

 Great Britain the proportions thus far are reversed ; the tallest 

 observed specimens of the former do not exceed 30 feet, while 

 specimens of B. pisif era are to be seen 40 feet high. Both in 

 habit and aspect the two species may be readily distinguished 

 from each other ; in B. pidfera the branches, both primary and 

 secondary, are longer and more slender than in B. obtusa, and the 

 tree more open. B. obtusa has a more regular conical outline, 

 denser in aspect, deeper in colour. Neither of them have the 

 massive, almost columnar growth of their North American 

 affinities, Cupressus Laiusoniana and C. nootkatensis [Tliuyopsis 

 borealis). 



The varieties of both species are dwarfer, more compact, and 

 of slower growth than the types. Of the obtusa varieties 

 filicoides and lycopodioides are dense bushes remarkable for the 

 peculiar form of their branchlets and the rich green of their 

 foliage ; the best-coloured form is gracilis aurea, the smallest 

 is pygmcBa, a dense tuft useful for the rockery. Of the pisifcra 

 varieties plumosa is a universal favourite ; its sub-variety aurea 

 said pisif era aurea are the richest-coloured forms to be found 

 among Eetinosporas, while squarrosa, a juvenile form, is almost 

 unique in its grey primordial foliage ; filifera also is a striking 

 form on account of its slender drooping branchlets. The chief 

 drawback attending these Conifers is that they will not grow 

 everywhere ; they fail entirely in a chalk soil and in soils with 

 a limestone substratum. Even amidst the rich coniferous sur- 

 roundings at Eastnor Castle, Mr. Coleman informs me that the 

 Eetinosporas do not thrive. A good retentive soil with a porous 

 substratum suits them, such as we find in the sandy loam at 



