299 



AN ESSAY AT A KEY TO BRITISH RUBI. 



By the Rev. W. Moyle Rogers, F.L.S. 



(Continued from p. 272.) 



Group 6. Radulje. — St. for the most part low-arching, and 

 producing rooting branches ; generally as in the Egregii, except in 

 having their faces rough throughout with numerous subequal short 

 pricklets or their tubercular bases, acicles (glandular and eglandular) 

 and shortly stalked glands ; without the series of medium-sized 

 prickles that occur in the Koehleriani. The large prickles nearly 

 confined to the angles, subequal. Pan.-rachis abundantly furnished 

 with rather shortly stalked glands and acicles ; the lateral branches 

 umbellate-racemose or cymose ; the petals usually pale pink or 

 white. In our species the stam. are uniformly longer than the 

 styles, except in Babingtonii and foliosus, where they about equal 

 them ; while in rudis and melanodermis the styles are somewhat ex- 

 ceptionally prominent, though still below the level of the stamens. 



Dr. Focke remarks that in many species of the preceding groups 

 there occur forms with st. rough with tubercles (as, e.g., in A 

 Drejeri), and that these forms probably do not admit of separation 

 from the Radula by definite characters ; while on the other side a 

 sharp separation from the Hystrtces (Koehleriani) is impossible, 

 because in certain species and forms the intermediate medium- 

 sized prickles occur, though rarely. "Still," he adds, ''in the 

 great majority of instances the Raduljs are thoroughly charac- 

 teristic." 



The following subdivisions will, I think, be found fairly reliable, 



so far as they go; but I fear that they are too vague and in- 

 determinate to be of much real value : 



A. Larger prickles usually strong, subequal, almost wholly 

 confined to angles:— (50) radula and vars. ; (52) echinatus ; (53) 

 rudis. 



B. Sub- Koehleriani. — Larger prickles unequal (the largest 

 usually very strong), almost wholly confined to angles : — (51) New- 



bouldii; (54) prceruptorum ; (55) melanodermis ; (56) coynatus ; (57) 

 Babingtonii. 



C. Sub-Bellardiani. — Larger prickles usually not so- strong, 

 rather more scattered and unequal. St. often less angular : — (58) 



scaler; (59) fuscus and var. ; (60) pallidas ; (61) Lintoni ; (62) 

 Lejeunei; (63) Ehenanns ; (<J4) longithyrsiger ; (65) foliosas. 



50. R. radula Weihe. — St. strong ; often rather high-arching, 

 though usually nearly prostrate in S. Engl. ; angular, thinly hairy, 



tvith Jlat faces rough with short tubercles stalked glands and acicles. 



The large prickles strong, subequal, confined to angles, mostly 

 declining. L. chiefly 5-nate-pedate. Lts. long-stalked, and so wide- 

 spread, opaque, plicate, rather pale green above, with close white felt 



(afterwards becoming grey) beneath, doubly sharply dentate-serrate ; 



term, usually ovate-acuminate from nearly entire or subcordate 



