COMATRICHA 177 



8. COMATRICHA LAXA Rost. 



Mon. 201. 1875. 

 PI. XII, Figs. 288, 289, 290. 



1877. Lamproderma ellisiana Cooke, Ann. Lye. Nat. Hist. N. Y. 11 : 397. 



1884. Comatricha macrosperma Racib., Rozpr. Akad. Krak. 12 : 76. 



1891. Comatricha ellisiana (Cke.) Ell. & Ev., N. A. Fungi No. 2696. 



1892. Comatricha sommerfeltii Blytt, Bidr. K. Norg. Sop. 3 : 8. 

 1892. Stemonitis laxa (Rost.) Massee, Mon. 79. 



Sporangia scattered, gregarious, subglobose or short-cylindric and 

 obtuse, dusky, stipitate, 1-2.5 mm. tall; stipe short, black, tapering 

 rapidly upward from an expanded base; hypothallus scant or none; 

 columella erect, rigid, sometimes reaching nearly to the apex of the 

 sporangium, sometimes dichotomously branched a little below the 

 summit before blending into the common capillitium; capillitium lax, 

 of slender, horizontal branches, anastomosing at infrequent intervals 

 and ending in short, free tips; spores purplish brown, minutely warted, 



7-11 m- 



A minute, delicate little species; the stipe half the total height. In 

 general appearance the shorter forms resemble C. nigra, but are dis- 

 tinguished by a shorter stipe and more open capillitium. The sporangia 

 of C. nigra mounted on long capillary stipes always droop more or less; 

 the sporangia of the present species stand rigidly erect. The sporangia 

 vary in form and in the branching of the columella. In the more globose 

 phases, the columella almost always shows a peculiar dichotomy near 

 the apex; in the cylindric types, this peculiar division fails. In fact, 

 the shape is determined chiefly by the mode of branching of the colu- 

 mella. Rostafinski's figure, on pi. XIII, does not present the type 

 usually seen in this country, nor even in Europe if we may judge from 

 later illustrations. Celakowsky's illustrations (Myx. Bohm. pi. 2, 

 figs. 7, 8) are better. 



The species with us has received various names, but so far as can be 

 determined, all apply to the same thing, and comparison of specimens 

 from Mr. Ellis with those from Europe shows the correctness of the 

 nomenclature here adopted. 



The var. rigida Brandza is characterized by scanty, rigid capillitium 

 and slightly larger spores. 



Forms with larger spores have been reported, including a form with 

 very minute globose sporangia, a scanty capillitium and spores 12-14 /x 

 in diameter, described by Meylan (Bull. Soc. Vaud. Sc. Nat. 53 : 456, 

 1920) as var. microcarpa. This may prove to be distinct. 



Rare, but widely distributed in North America; also Europe, 

 Malay Peninsula, Manchuria, Japan. 



