892 AQUATIC PHYCOMYCETES 



Araiospora streptandra var. streptandra Kevorkian 



Mycologia, 26: 151. 1934 

 (Fig. 70 G, p. 890) 



"Large sub-cylindrical basal cell with many branches arising from 

 the sub-conical apex. Branches separated by constrictions and repeated- 

 ly and umbellately branched, each successive segment becoming more 

 elongate and slender than its predecessor. Sporangia borne singly or in 

 whorls of two to six of two types (1) sub-cylindric or broadly clavate 

 and smooth, 79-1 1 1 < 29-49 u., (2) oval or pyriform and spiny, 60-78 x 

 46-63 [A. Spines numerous, 1 5 to 30 \i in length, elongate conical in shape. 

 Antheridia borne singly on short, stout lateral branches, usually origi- 

 nating near the distal ends of the segments, twisted about the base of the 

 oogonia, irregular in outline. Oogonia spherical, 52-68 u. (av. 60-64 u,), 

 arising similarly to and usually near the antheridia. Oospore spherical, 

 39 to 46 [i (av. 44 to 46 \l), surrounded by a single layer of hexagonal- 

 appearing peripheral cells derived from the periplasm. Germination of 

 the oospore not observed ,, (Kevorkian, loc. cit.). 



On submerged twigs of Primus and Salix (F.), Webster (1943: 31), 

 United States. 



Distinguished from Araiospora pulchra, which it most closely resem- 

 bles, by the twisted unbranched irregular antheridium, which arises as a 

 short lateral branch near the tip of a segment. 



Araiospora streptandra var. echinulosphaera Shanor and Olive 

 Mycologia, 34: 540, figs. 1-11. 1942 



Echinulate sporangia spherical, 29.8-48.7 u. in diameter, the spines 

 many, for the most part 30 to 50 in number, 3.1-20.4 u. long. 



Twigs of birch, United States. 



The antheridia of this variety were larger and more toruloid than 

 Kevorkian's, a feature not included in its diagnosis. 



Some young spinose sporangia were destroyed by an unnamed 

 species of Rhizophydium. 



