307 



lorous with the internodes : I have faithfully transcribed both of the 

 original descriptions. Moreover, on consulting Professor Vaucher's 

 ' Monographic des Preles,' published in the first volume of the ' Me- 

 moires de la Societe de Physique, etc. de Geneve,' I find that learned 

 author has not only described at length but figured (PI. VI.) Willde- 

 now's plant under Desfontaine's prior name of Equisetum ramosissi- 

 mum : the subduplicato-ramose and verticillate characters of the stem 

 as well as the concolorous sheaths are well represented. Vaucher gives 

 the appropriate name of Equisetum multiforme to a species which ap- 

 pears to include the variegatum of Schleicher's Catalogue and various 

 other forms, among these the present plant is not distinctly charac- 

 terized : his (3. Equisetum multiforme ramosum, which, in other re- 

 spects, comes the nearest, having the sheaths differently coloured. — 

 His description of this variety is quoted below.* 



This author, in his introductory remarks on the genus, aptly cites 

 this species as an instance of characteristic liability to variation. Af- 

 ter mentioning that the Equiseta generally occur on the banks of 

 streams and in damp places, as well as in the water, he says they are 

 occasionally "even met with in sandy places that are not watery, such 

 is the case with Equisetum multiforme : this species appears strongly 

 influenced by the properties of the soil in which it grows, for some- 

 times it throws out but a small number of slender and short branches, 

 at other times, on the contrary, and especially when in a more fertile 

 soil, we find issuing from the principal stem branches not only much 

 longer but much more divided, so much so indeed that it has been 

 thought it could not then be referred to the same species."t 



*^. Equisetum multiforme ramosum. Prele multifoi'me ranieuse. Cette seconde 

 variete est peu connue des Botanistes quoiqu'elle soit assez repandue ; elle emet de sa 

 racine plusieurs tiges courtes semblables a celles de la variete a. dont les gaines sont 

 plus ou moins noiratres ; mais on y observe encore une ou plusieurs tiges principales, 

 qui peu vent s'elever jusqu'a trois pieds et qui sont terminees par un epi plus grand que 

 celui de la variete a. Les gaines sont amples, assez laches, blanches ou brunes, mais 

 rarement noires ; les rameaux sont assez nombreux, plus ou moins reguliers, et quel- 

 quefois proliferes. Cette variete j3. se trouve souvent reunie a la premiere, et Ton 

 pent facilement observer des echantillons qui presentent toutes les nuances intermedi- 

 aires. Ordinaireraent la Prele rameuse se rencontre dans des terrains plus riches et 

 plus favorables a la vegetation. — ' Memoires de la Societe de Physique et d'Histoire 

 Naturelle de Geneve.' i. 379. 



f On en rencontre menie dans les terrains sablonneux et non humectes, comme 

 par exemple la Prele multiforme; mais cette derniere espece paroit elre fortement in- 

 flueucee par la nature du terrain dans lequelle elle croit, car tantot elle ne developpe 

 qu'un petit nombre de tiges greles et fort courtes, tantot au contraire, et surtout lora- 

 qu'elle sort d'un terrein plus riche, on voit sortir de la touffe principale des tiges beau- 



2 c 



