676 LOCOPODIACE.E. (club-moss family.) 



cies; macrospores (0".32-0".38 wide) covered with short and twisted crested 

 ridges, which often anastomose ; microspores (0". 01 7-0". 020 long) smooth. — 

 Mountain lakes, Penn., New York, and New England to Lake Superior, and 

 northward often with No. 3. (Eu.) — The American is distinguished from the 

 European plant by the larger macrospores, therefore I. macrospora, Durieu. 



2. I. Tuekermani, Braun, n. sp. Leaves (10-30, 2' -3' long) very 

 slender, awl-shaped, olive-green, the outer ones recurved; sporocarps ovoid or 

 circular, the upper third covered by the velum, the free part sometimes brownish- 

 spotted; macrospores (0".22-0''.28 wide) on the upper segments covered with 

 parallel and anastomosizing ridges, the lower half reticulated ; microspores 

 (0". 013-0''. 015 long) smooth or very delicately papillose. — Mystic and other 

 ponds near Boston, together with the next, Tuckerman, W. Boott. 



3. I. echinospora, Durieu. Leaves slender, awl-shaped; sporocarps 

 ovoid or circular; macrospores (0".20-0".25 wide) beset all over with small 

 entire and obtuse or slightly forked spinules. (Eu.) — In the European form, 

 which has not yet been found in America, the leaves are very slenderly attenu- 

 ated (3' -4' long), the upper margin of the sporocarp only is covered with the 

 narrow velum, the free part is unspotted, and the slightly papillose microspores 

 are larger (0".015-0".016 long). The following are the American forms of 

 this species. 



Var. Braimii. Leaves (15-30 in number, 3'-6' long) dark and often 

 olive-green, straight or commonly recurved, half or two thirds of the sporocarp 

 covered by the velum, the free part often with light brown spots ; macrospores 

 as in the species; microspores smaller (0".013-0".014 long), smooth (I. Braunii, 

 Durieu.) — Ponds and lakes, New England to Western New York and north- 

 ward, often with the two preceding. — Often with a few stomata, especially in 

 Niagara specimens. 



Var. muricata. Leaves (15-30, 6' -10' long) straight or flaccid, bright 

 green ; about one half of the almost circular sporocarp covered by the velum, 

 unspotted ; macrospores (0".22 -0".27 wide) with shorter and blunter spinules ; 

 microspores as in the last variety, or rarely spinvdose. (I. muricata, Durieu.) — 

 In some ponds north of Boston, W. Boott. 



Var. Boottii. Leaves (12-20, 4' -5' high) awl-shaped, stiffly erect, bright 

 green, with stomata; sporocarp as in last; macrospores as in the species, but a 

 little smaller and with very slender spinules. (I. Boottii, Braun, in lift.) — Pond 

 in Woburn, near Boston, partly out of water, W. Boott. 



# * Growing partly out of water, either by the pond drying up, or by the receding of 

 the ebb tide ; leaves with stomata, and in 6 and 7 with four or more peripherical 

 bast-bundles. 



4. I. saceharata, Engelm., n. sp. Leaves (10-15, 2'-3' long) slender, 

 olive-green, curved ; sporocarps small, ovoid, only the upper edge covered by the 

 velum, nearly unspotted; macrospores (0".20-0".22 wide) minutely tubercu- 

 late; microspores (0".012 long) papillose. — On Wicomico River, eastern shore 

 of Maryland, between high and low tide, W. M. Canby. 



5. I. riparia, Engelm. Leaves (15-30, 4' -8' long) slender, deep green, 

 erect ; sporocarps mostly oblong, upper margin to one third covered by the 



