6 Mindeskrift for J. Steenstrup. XXI. 



root, which is slender, and ramified. There is an overwintering rosette of leaves, and 

 the shoot is monopodial as in the species described above. But a notable difference 

 exists in the production of stolons, which are above ground, and which consist of one 

 long internode. In this way the species is better equipped, so far as concerns the vege- 

 tative reproduction, than any of the others of this section. The leaf-structure is dors- 

 iventral with a very open pneumatic tissue, thus illustrating a plant well adapted to 

 an atmosphere charged with excessive moisture, the conditions under which this species 

 is able to thrive. 



Euclaytonia thus contains species of a somewhat different habit, and of a relatively 

 distinct anatomicai structure. However characteristic of all these species is the large 

 development of the root, the monopodial ramification of the shoot, and the simple com- 

 position of the inflorescence, provided with two large foreleaves. 



Limnia. 



Before the publication of "Species plantarum" Linnaeus had Claytonia Sibirica 

 under the genus Limnia; but since then it was referred to Claytonia together with Cl. 

 Virginica. 



Claytonia asarifolia Bong. 



This species is perennial by a horizontally creeping rhizome, and the ramification 

 is monopodial, the apex of the shoot being vegetative. The two prophylla are large, 

 but the inflorescence is simple, mostly a monochasium, and with no bracts to the flowers. 



Claytonia Sibirica L. (Plate III fig. 1). 



This resembles the preceding species very much, but it is mostly annual; however 

 a perennial form does occur, and at this stage stolons become developed. In respect 

 to the inflorescence this is generally very rich-flowered, beginning with a true cyme, 

 the lateral branches of which may continue as cymes or pass gradually into monochasia; 

 the floral bracts are nearly always developed. An interesting form has been described 

 by W. N. Suksdorfi) as Cl. Washingtoniana, which is a small, delicate, annual plant 

 with only a few flowers. 



Of the same habit, but strictly annual are Cl. arenicola Henders., Cl. perfoliata Don., 

 Cl. parviflora Dougl,, and the very narrow-leaved Cl. gypsophiloides Fisch. et Mey., 

 and Cl. spathulata Dougl. In the two last species the flowers are usually destitute of 

 bracts, except the central. Characteristic of the section Limnia is, thus, the very broad 

 prophylla, and the slender roots of short duration. 



») Deutsch. Botan. Monatsschr. 1898, p. 220. 



