ACHLYA GLOMERATA sp. nov. 



W. C. COKER 



(With Plate 79, Containing 7 Figures) 



Hyphae rather stout, branched, not long. About 40-45 mu in 

 diameter at base and tapering to slender tips about 12 mu in 

 diameter at base and tapering to slender tips about 12 mu in diam- 

 eter. At maturity, the main hyphae strongly incline to segment into 

 elongated sections with dense protoplasm, but the slender apical 

 section is apt to remain almost empty (fig. i). Zoosporangia 

 almost cylindrical, inclined to be somewhat irregular and often 

 opening by a bent papilla (fig. 2). Oogonia abundant, approxi- 

 mately spherical, without pits ; completely covered with short, 

 blunt irregular warts (fig. 3). Oogonia borne on the tips of very 

 slender and delicate, but contorted lateral branches that are either 

 simple, in which case there is but one oogonium (fig. 3), or more 

 or less intricately branched, in which case there are a number 

 of oogonia borne on the tips of the group of branches (figs. 4, 5, 

 and 6) . Oospores single or very rarely two in an oogonium ; their 

 diameter 15-23 mu, averaging about 20 mu. Antheridia absent 

 from a good many oogonia, when present, club-shaped ; borne on 

 the tips of branches from the same glomerulus and one or several 

 on an oogonium (fig. 5). 



This species has been observed several times from two stations 

 at Chapel Hill, North Carolina. The drawings are made from 

 material taken from a cool spring in dense woods (''Lone Pine 

 Spring") on April 30, 1912, and from the springy marsh at the 

 foot of ''Lone Pine Hill" on February 29, 1912. Pure cultures 

 have now been kept for about six months. 



This species does not closely approach any other; but it seems 

 to be nearest the members of the racemosa group. The shape of 

 the antheridia is like those of A. racemosa and its relatives, and 

 there is considerable resemblance to the spiny oogonia of A. race- 

 mosa stelligera and to A. decorata, if these two are really distinct.^ 

 There is also some hint of the habit of A. glomerata in the occa- 

 sional branched oogonial threads of A. decorata. In all the 



* Obel considers A. decorata Peterson the same as A. racemosa var. spinosa 

 Cornu (Annales Mycologici 8: 422. 1910) : and Humphrey gives the latter as a 

 synonym of A. racemosa var. stelligera Cornu. 



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