﻿242 



taxonomic importance. Among the further characters given by 

 Grisebaoh, the broader leaves answer to the form ovata of Detharding 

 and Fischer-Benzon, hence Grisebach's form, and Calvert's, which 

 is identical with it, that is, the coast form from the Sea of Marmora 

 and the Hellespont, and Schweinfurth's form from Sardinia, present 

 a combination of all the three variations of Sherardia arvensis 

 hitherto described. It must be observed that the arrest of growth 

 of the calyx is not in any way connected with the sexual differences 

 in Sherardia first noticed by Hermann Mueller." The specimens 

 examined by Ascherson had bisexual flowers. Wirtgen had 

 remarked that the hairs on the teeth disappear as the reduction 

 increases, and Ascherson points out that is also the case on the 

 ovary and fruit. The specimens from the Hook, from Dresden and 

 Hersek, showed a particularly scanty array of small bristles on 

 the fruit, which is the more striking because all three belong to the 

 var. hirsute of Baguet. Ascherson goes on to say that the chief 

 interest attaching to this form lies in this, that it throws gravest 

 doubt upon the value of the character by which Sherardia has 

 for nearly two hundred years been distinguished from Asperula, 

 especially as the calyx in Asperula and Galium, according to 

 frequent statements in the literature, is sometimes found more 

 distinctly produced than usual. For this reason Hock has sup- 

 pressed Sherardia, and follows Boerhaave and Baillon in restoring 

 the single species to the genus Asperula (under the name of 

 A. Sherardi), from which Dillenius had separated it. In deter- 

 mining the question whether this reduction is admissible, the 

 other genera of Stellate must be considered. 



Of the British genera, Rubia is known by its succulent fruit, 

 but the separation from each other of the genera Galium and 

 Asperula leaves much to be desired in point of clearness and 

 naturalness; the difference in the length of the corolla-tube in 

 many cases is so dubious that not a few European species have 

 been placed in either genus by different or by even the same 

 author. On the whole, there is so great agreement between single 

 species and groups of species in Asperula and Galium, pointing to a 

 real phytogenetic affinity, that a truly natural arrangement should 

 not turn on the character which is derived from the length of the 

 tube, and which is so often uncertain. The close affinity of our 

 Woodruff, Asperula odorata, with Galium triJUmm, which also con- 

 tains coumarin, is undeniable ; between Asperula laevigata and 

 Galium rotimdifolium, and, to omit others, between Asperula 

 Aparine and Galium uUginosum. Scopoli had the same conception 

 of the matter, for in the Flora Carniolica he placed most of the 

 species of Asperula under Galium, not as a separate section or 

 subgenus, but in different places among the species of Galium. 

 Ascherson agrees with Scopoli in the opinion expressed in the 

 Flora Carniolka, i. p. 99, that the characters of the fruit are in this 

 case more important than those of the flower. 



Such being the uncertain state of the delimitation of the genu3 

 Asperula, it is necessary to proceed with especial care in the 

 absorption of Sherardia into it ; and it is right to ask— are there 



