39. R. BALFOURIANUS. 257 



tonis oblong ; primordial fruit-stalk scarcely ever as long as 

 the sepals which are patent but bend upwards so as to clasj» 

 the fruit. Nut very broad, roundly i-ovate ; inner edge 

 straight or concave. 



The original It. Balfourianus is usually an exceedingly 

 luxuriant plant, with enormous leaves upon both shoots, 

 and a veiy large and very loose panicle. The first stej> 

 from this is my former R. fusco-ater 8 suhglaher which has 

 a large dilfuse, much more prickly, but less hairy, although 

 finely felted panicle. It has more and stronger but short 

 aciculi on tlie stem, and leaves with fewer and shorter hairs 

 beneath. The next step is formed by a plant having a 

 small diffuse and corymbose panicle. And, lastly, I am 

 unable to separate from the preceding the R. tenuiar- 

 matus (Lees) my authentic specimen of which has a long 

 leafy panicle with a corymbose top, and rather short and 

 slightly racemose branches. The weak and abundant 

 prickles, upon Avhich the name is founded, "broken at the 

 slightest touch," shrink after the specimens are gathered so 

 as to become exceedingly compressed, but seem to spring 

 from a somewhat cushionlike base which is oblong but not 

 compressed : on the older stems this tendency to bhrink 

 cea-ses, but the prickles are very slender and much com- 

 pressed. They are accompanied by plenty of short and 

 strong aciculi. Typical R. Balfourianus has veiy few 

 aciculi and much fewer prickles than R. tenuiarmatus. 



Although the typical forms are very different, it is not 

 always easy to distinguish this plant from R. cori/Hfoliu.s' ; 

 for the R. tenuiarmatus approaches it closely. Usually the 

 hairy but not felted under side of the leaves, the open 

 panicle with scattered flowei-s, together with the long much 

 more hairy and often leaf-pointed erect-patent sepals, will 

 separate the R. Balfourianus from its ally : but sometimes 

 the under side of the leaves of R. corylifolius is scarcely 



22-3 



