392 
MARS1LEACE/E LYCOPODIACEiE. 
Order XCIV. MARSILE ACEjE. 
Creeping plants with alternate erect leaves having a circinate 
vernation. Fructification consisting of globular nearly sessile 
coriaceous bodies with 3 or 4 cells and containing sacks inclu- 
ding either other bodies that germinate or loose granules. 
1. Pilularia. Involucres solitary, nearly sessile, globose, 
coriaceous, 4-celled. Cells containing bodies of 2 kinds, 
granules and membranes containing minute grains. 
1. Pilularia Linn. 
1. P. globulifera (L.). The only species.— E. B. 521— Rhi- 
zoma elongated, creeping, producing leaves and roots at regular 
intervals. L. very slender, erect. Caps, slightly stalked, axil- 
lary, nearly spherical, hairy. — Margins of ponds and lakes. 
P. Pillwort. 
Order XCV. LYCOPODIACE^. 
Leafy plants with simple imbricated leaves ; or stemless with 
erect subulate leaves. Fructification of axillary sessile thecse 
with 2 or 3 valves and no ring, including minute powdery matter 
or sporules. 
* Caps, not opening. 
1. Isoetes. Fructification inclosed within the swollen base 
of the leaves. Sporules of two kinds attached to filiform 
receptacles. 
** Caps, bursting. 
2. Lycopodium. Caps. 1 -celled, 2-valved, containing pow- 
der ; or 3-valved, containing 1 — 4 granules. 
1. Isoetes Linn. 
1. I. lacustris (L.) ; 1. subulate roundish-quadrangular with 4 
longitudinal jointed tubes. — E. B. 1084. Hook. Lond. t. 131. — 
Rhizoma a blunt tuber. L. slender, broad and flat at the base 
but elsewhere between cylindrical and quadrangular. There is 
still some doubt about the internal structure of the capsules. — 
Bottom of lakes and ponds in hilly districts. P. Quill-wort. 
2. Lycopodium Linn. 
1. L. clavatum (L.) ; 1. scattered incurved with a filamentous 
point, spikes stalked 2 or 3 together cylindrical, scales ovate- 
triangular membranous finely inciso-serrate. — E. B. 224. — St. 
prostrate, many feet long. Branches short, ascending. Spikes 
