ISOETES. LYCOPODIUM. 535 



1. ISOETES Linn. Quillwort. 



* Xo persistent leaf-bases. Caps, not wholly covered by the 

 membranous edge of the pouch. Back of swollen leaf-base 

 smooth. Aquatic. 



1. 7. lacus'tris (L.) ; 1. subulate roundish-quadrangular with 

 4 longitudinal jointed tubes upright dark green, larger spores 

 bluntly tuber cled rather mealy ^ tubercles overtopped by the 

 valve-edges. # B. 1084. H. F. 55. R. vii. 1. Conn with 

 longitudinal furrows. L. slender, broad and flat at the base, 

 but elsewhere between cylindrical and quadrangular, 2 6 in. 

 long. /. Morei (Moore) is a form with exceedingly long leaves. 

 J. of B. xvi. t. 199. Usually caespitose on the sandy and stony 

 bottom of lakes and pools in hilly districts. P. VI. E. S. I. 



2. 1. echinos'pora(D\\Y. !) ; 1. subulate roundish-quadrangular 

 with 4 longitudinal jointed tubes patent pale green, larger spores 

 very acutely tuber cled, tubercles overtopping the valve-edges. 

 J. of B. i. t. 1. Much like Sp. 1. Conn not furrowed. L. 

 turning yellow, less rigid, flattened and dilated below. Spores 

 covered with long acute spine-like tubercles, not mealv. 

 Usually solitary on the muddy bottom of pools and lakes in hilly 

 districts. Llanberis, N. Wales. Loch of Park near Aberdeen. 

 Ben Voirlich, Dumbartonshire. [Near Tongue, Sutherl.J . Gap of 

 Dunloe, Kerry. Galway. Mayo.] P. VI. E. S. I. 



** Corm more or less covered by the persistent hardened leaf- 

 bases. Caps, wholly covered by the membranous edge 

 of the pouch. Swollen leaf-base with a central longitudinal 

 rugose band on the back. Terrestrial. 



\_L Hys'trix (Dur.) ; 1. filiform plane-convex obscurely tubu- 

 lar, persistent l.-bases short blackish each with 2 long horns and 

 an interm. tooth, larger spores white and bluntly tubercled. 

 /. Duricei H. F. 56. Corm small, rarely if ever quite naked. 

 L. very slender, ultimately very much enlarged at the base to 

 enclose the capsule, 1 2 in. long, annual. Dampish sandy and 

 stony places. L'Ancresse, Guernsey. Mr. G. Wolsey. [Alderney. 

 Mr. k D. Marquand.'] P. V. VI.] 



2. LYCOPO'DIUM Linn. Club-moss. 



* St. creeping, prostrate. Caps in term, spikes, with bractlike 

 leaves. LEPIDOTIS Palis. 



1. L. clavdtum (L.) ; 1. scattered imbricate incurved hair- 

 pointed, spikes stalked 2 or 3 together cylindrical, scales ovate- 



