310 



h. — A basidium with only one sterizma and one spore. 



1.— Detail of a crop of bristles, showing; manner of extrusion, position, etc. 



^Tichcnera ariocreas^ B.&rC, 



k. — A hypha which has swelled at its tip. The tip is already cut off from the parent 

 hypha by a cross partition. The tip is more granular than the rest of the fila- 

 ment. 



1. — A tip which has broken from the hypha after the lash-like process from its top 



has been developed. The walls are still thin and the spore has not been formed. 

 m, — A tip cell whose much thickened walls enclose a dark granular spore (sp). The 



flagellate tip shows some tendency to curl. The neck of the mother-cell is 



almost completely closed by the thickening of its walls. 

 n.^A section through the hymcnium of AT. artocreas. 



T. — Layer in which filamentous paraphyses are the principal elements. 



11. — Spore-layer, mother-cells of spores lying loosely among filamentous para- 

 physes. 



III. — Layer of spore-bearing hypha: which are separated from each other by 



paraphyses. 

 IV. — Mycelium at base of hymenluni, showing that both paraphyses and sporo- 



phores are continuous with ordinary mycelial hypha?. 



Cryptogam ic Lai^oratort, 



Harvard University, June, iSgo, 



"-1 



New or Noteworthy North American Phanerogams.— III. 



By N. L. Bri'iton, 



Ranunculus Porteri, n. sp. ^Batrachium. Submersed, 

 apparently several feet loni^, freely branching. Leaves petiolcd, 



the petioles y^' to i' long, and dilated at the base, the 

 blade about i^' in diameter repeatedly ternately divided into 

 linear or capillary segments; the upper shorter and broader; 

 flowers white, 3" to 4'' broad, peduncled; achencs 6 to 12 in a 

 head, obhquely oval, compressed, somewhat pubescent, margin- 

 less, very nearly i^' long, beaklcss or with a mere apiculation, 

 \rregularly rugose transversely; receptacle pubescent. 



I noticed this plant in Dr. Porter's Herbarium a year or so 

 ago. The accompanying label has only '' Henry's Fork, No, 

 1062; Ranunculus, entirely immersed." It was collected on the 

 Hayden Survey of the territories, but I cannot place the exact 

 locality. 



The species differs from any form of R. aquatilis \v\^\ which 

 I am acquainted, in its much broader and fewer leaf-segments 

 and larger achenia. I sent it to Mr. Baker at Kew, who thinks it 



r 



not related to any European form of that plant, remarking that 

 ** no European form ever shows so much transition between float- 



