I 



90 MEMOIRS OF THE XEW YORK BOTAXICAL GARDEX 



Stigonema cornutum sp. nov. 

 Plate 21, figure 53 



Filaments very irregular in shape and size, the main part 

 usually very blunt, 2->-30 |j (up to 50 m) diam. ; branches of two 

 sorts, one similar to the main frond, sparse, arising without any 

 order, deeply constricted at the base, later completely separated 

 at the constricted base from the parent frond; the other more 

 numerous, arising in a similar manner, smaller, bearing a long, 

 sharp, usually curved, hyaline apex, changing to amber color 

 after the hormogonia disappear, the latter may or may not be 

 deciduous ; cells 4-6-seriate, 8-12 m diam. ; heterocysts small, 

 rather sparse; sheath homogeneous, hyaline, changing to 

 slightly yellowish when old. 



Growing on soil along the road towards Monte Montoro, 

 Maricao, no. 1077, type; on moss, fern roots, etc., between Aibo- 

 nito and Cayey, no. 1975. 



The cornute habit of Stigonema cornutum reminds one of 

 Kuetzing's Stigonema polyceras (1851, pi. 38) in which the 

 attenuated portion contained cells. It was learned later that 

 Kuetzing's plant is a lichen. The attenuated portion of the 

 branches in the above species consists of homogeneous, hyaline 

 tegument, and the plant is a typical Stigonema. The cells in no. 

 1290 are larger than those of the type and more regularly ar- 

 ranged in nodes. 



Stigoxema mixutum parciramosum var. nov. 



Filaments blunt and irregularly bent, not oriented into upper 

 and lower ends, smooth and fairly regular on the surface, very 

 sparsely and irregularly branched, 28-32 u diam. ; hormogon- 

 iferous branches 30-45 |j long, other branches similar to the main 

 filament; cells 4-6-seriate, longer than the diameter, finely gran- 

 ular, bright bluish-green; tegument thin, firm, smooth, homo- 

 geneous, yellowish brown. 



Growing on "Flytteblok," west of Humacao, no. 568, type. 



Stigoxema mixutum tuberculatum var. nov. 



Filaments very crooked and tuberculate, branching very ir- 

 regular, numerous; cells distributed without order; tegument 

 hyaline, changing to yellowish brown, homogeneous. 



Growing on "Flytteblok," west of Humacao, no. 571 a, type, 

 and no. 566 a. 



