112 BRITISH PERNS. 



ones, and have less inflated sheaths. This species, there- 

 fore, in its habit of growth, holds a middle place between 

 that group in which the fertile and barren stems are suc- 

 cessive and quite dissimilar, and that group in which they 

 are simultaneous and present no appreciable difference of 

 structure. 



The fertile stems, when they first shoot up, are almost 

 quite simple, and a few of them remain so, perfecting their 

 cone-like head, and then perishing. More usually, by the 

 time the catkin has become fully grown, the whorls of 

 branches from the upper.joints will be seen protruded to the 

 length of from half an inch to an inch or rather more. Two, 

 three, or four, rarely more, whorls of branches are thus pro- 

 duced from the uppermost joints of the stem, and above these 

 the oblong-ovate blunt cone is seated on a bare stalk-like 

 portion of the stem. The stems are about a foot high, round, 

 succulent, pale-coloured, with about twelve slender ridges 

 and corresponding shallow furrows, nearly smooth, the sili- 

 cious particles which coat the surface being too minute 

 to impart much roughness ; they terminate in an oblong, 

 ovate cone of fructification. The sheaths are large and loose, 

 and are divided at the margin into three or four bluntish 

 lobes ; their lower half or tubular portion is pale green, 

 the ui 

 whic 

 length, 

 branches, which grow from about half an inch to an inch. 



The barren stems are taller, more slender, and less succu- 

 lent, and also produce more numerous whorls of branches. 

 The sheaths fit closer than those of the fertile stems ; and 

 the whorls of branches are very dense, being compoundly 

 branched. The main branches are three-ribbed, their joints 

 termiiicating in three long pointed teeth ; they are about four 

 inches in length, constantly branched at every joint with a 

 whorl of branchlets averaging two inches in length, and 

 sometimes these branchlets put out another series of shorter 

 branchlets. The oiitline would be pyramidal, were it not 

 that the extreme point becomes so slender as to be unable to 

 retain itself erect. The lateral branches are all drooping or 

 deflexed, and hence the elegant appearance of the full-grown 

 plants. 



The section of the stem shows a series of shallow ridges 

 and furrows ; opposite the latter a ring of largish cavities ; 

 and alternating with these on the inner side, another ring of 

 very minute cavities, these latter again alternating with a 



