101. MAESHEACEJil. — 102. LTCOPODIAOBJ!. 465 



19. Ophioglos'sttm Linn. Adder's-tongue. 



1. O. viilgdtum (L.) ; frond ovate Hunt, epidermal cells 

 flexuose, spores tuberoled.— ^. B. 108. H. F. 46. N. 349. 

 — Height 4 — 12 in., erect. Spike clubsliaped, usually rather 

 longer than the frond, sometimes very long. — /3. amhiguum 

 (0. & G.) ; rhizome often producing two fronds from the 

 same joining, frond ohlong-lanceolate narrowed below 2 — 4 in. 

 high.— Pastures. /3. Orkney. Scilly. P. V. VI. E. S. I. 



2. 0. lusitan'icum (L.) ; frond linear-lanceolate, epidermal cells 

 straight, spores smooth.— fi". F. 47. N. ed. 3. 331. S. 47.— 

 Height 1 — 2 inches, erect. — Horn Head, Co. Donegal. Petit 

 Bo Bay, Guernsey. P. I. I. 



Order CI. MARSILEACE^. 



Creeping plants with alternate erect leaves, circinate in bud. 

 Fructification consisting of globular coriaceous axillary bodies 

 with 3 or 4 cells and containing sacs including either other 

 bodies that germinate or loose granules. 



1. PiLTTLAEiA. Oapsules Solitary, nearly sessile, globose, 

 coriaceous, 2 — 4-oelled. Cells containing bodies of two 

 kinds — granules, and membranes containing minute grains. 



1. Piltjia'eia Linn. Pillwort. 



1. P. glohulifera (L.) ; ped. erect, caps. 4-celled. — E. B. 521. 

 H. F. 57. N. 393.— Rhizome slender, creeping, producing leaves 

 and roots at regular intervals. L. very slender, erect. Caps, 

 pubescent, slightly stalked, axillary, nearly spherical, hairy.— 

 Marguis of ponds and lakes. P. VI. VII. E. S. I. 



Order CII. LTCOPODIACE.S. 



Leafy plants with simple imbricate leaves, or stemless with 

 erect subulate leaves. Fructification of axillary sessile capsules 

 with 2 or 3 valves and no ring, including minute powdery 

 matter or spores. 



* Capsules not opening. — Leaves radical. 



1. IsoiJTBS. Caps, in pouches formed of the swollen bases of 

 the leaves. Spores of two kinds attached to filiform 

 receptacles ; those of the outer leaves large, of the inner 

 very small. 



x5 



