FAMILY POLYANGIACEAE 1025 



FAMILY IV. POLYANGIACEAE JAHN 



(Beitrage zur botan. Protistologie. I. Die Polyangiden . Geb. Borntraeger, Leipzig, 

 1924.) 



Diagnosis : In the fruiting bodies the more or less shortened rods lie in rounded 

 cysts of definite form. The well-defined wall is composed of hardened slime, and 

 is yellow, red or brownish. The cysts may be united by a definitely visible slime 

 membrane, the remnant of the vegetative slime, or they may be tightly appressed 

 and cemented by the scarcely visible remnants of the slime, or they may develop 

 singly or in numbers on a stalk. In the more highly developed forms the stalk branches 

 and carries the cysts at the tips of the branches. 



Key to the genera of family Polyangiaceae. 



I. Cysts rounded, not stalked, usually many (one in Polyangiurn simplex) lying 

 loosely in a slime membrane or closely appressed. 



Genus I. Polyangiurn, p. 1025. 

 II. Cysts not as in I. 



A. Cysts pointed at the apex, often completely concrescent, and united to large 



disks or spheres. 



Genus II. Synangium, p. 1032. 



B. Cysts free, single or many on a stalk. 



1. Cysts forming a disk, flattened dorsoventrally, like the cap of a Boletus, 



on a white stalk. 



Genus III. Melittangium, p. 1033. 



2. Cysts not forming a disk. 



a. Cysts rounded or elongate, single on stalks. 



Genus IV. Podangium, p. 1034. 

 aa. Cysts rounded or elongate or pointed, numerous on the ends of stalks 

 which may be branched. 



Genus V. Chondromyces, p. 1036. 



Genius I. Polyangiurn Link. 



(Link, Mag. d. Ges. Naturforsch. Freunde zu Berlin, 3, 1809, 42 ; Cystobacter Schroe- 

 ter, in Cohn, Kryptogamenflora v. Schlesien, S, 1, 1886, 170; Myxobacter Tha.xter, 

 Bot. Gaz., 17, 1892, 394.) 



Etymology : Greek poly, many and angion, vessels, referring to the numerous cysts. 



Diagnosis: Cysts rounded or coiled, surrounded by a well -developed membrane, 

 either free or embedded in a second slimy layer. 



The type species is Polyangiurn vitellinum Link. 



Key to the species of genus Polyangiurn. 



I. Not parasitic on water plants (algae). 

 A. Sorus not white or grayish in color. 

 1. Cysts rounded to spherical. 



a. Ripe cysts yellow, reddish-yellow, orange or light red; not brown, 

 b. Cysts several or numerous and small, 

 c. Not closelj' appressed. 



d. Slime envelope transparent white or colorless. 



e. Usually 10 to 15 cysts. Rods in cysts, 3 microns long. 

 Cysts 75 to 200 microns. 



1. Polyangiurn, vitellinum. 



