EARLY SPECIFIC NAMES 371 



One of these species I shall now call Bubus invisus (p. 374), it 

 being the plant which I have formerly described as Bubus Cana- 

 densis var. invisus. There can be no doubt, I think, of the distinct- 

 ness of this species from the common dewberry. Of the merits 

 of the other species, I am not so well convinced, although from 

 a study of material from several sources, I have decided to 

 separate it as a species. It is the form which has been described 

 by Torrey and Gray as Bubus villosus var. humifusus (see Fig. 77, 

 page 353). This plant has been recognized by Britton as specifi- 

 cally distinct, and he has named it Bubus Baileyanus. As before 

 said, however, this is the plant which Trattinnick has de- 

 scribed as Bubus Enslenii, and this name must stand. There 

 are still two or three forms of the common dewberry of the 

 North which may need to be separately named, and I suspect 

 that in the near future one or two of them will be elevated to 

 specific rank. One is the plant which I formerly described as 

 var. roribaccus, and the other is now described by Professor 

 Card, from notes in my herbarium, as var. Michiganensis (p. 374). 

 The history of Bubus Enslenii brings up an interesting 

 question in respect to the variation of the high-bush blackberry. 

 Torrey supposed this to be a form of the common blackberry; 

 and it has been generally considered by botanists that the high- 

 bush blackberry has trailing forms (p. 352). As a matter of fact, 

 however, it has not. There are certain hybrids between the dew- 

 berry and high -bush blackberry, but they are so distinct in their 

 characters as to be easily recognized. It was one of these 

 hybrids which Willdenow had when he made the name Bubus 

 lirtrropliHllus. The name was published with no description, 

 so that it is not allowed to stand in botanical nomenclature. 



The following running sketch will enable us to understand 

 the botanical characters of the East-American blackberries and 

 dewberries : 

 A. DEWBERRIES : plants trailing, or at most slightly ascending, 



usually rootiiit/ by means of tips. 

 B. Fruit normally black (soiHrtiincs running into white forms). 



c. Peduncles few- to several -flowered. 

 1. HI-BUS VILLOSUS Alton, Hort. Kew. ii. 210 (1789). B. Cuna- 



/fr/i.sj.s, authors, not Linn. Common dewberry (Figs. 74, 84). 

 A strong- growing prickly plant, mostly with glabrous stems, 



