FERN FAMILY. 33 
2. Polypodium polypodioides (L,. ) 
A. S. Hitchcock. 
Gray Polypody. (Fig. 72.) 
Acrostichum poly podioides I.. Sp. Pl. 1068. 1753. 
Polypodium incanum Sw. F1. Ind. Oce. 3: 1645. 
Polpodin m polypodioides A. §S. Hitchcock, 
Rep. Mo. Bot. Gard. 4: 156. 1893. 
Rootstock widely creeping, woody, cov- 
ered with small brown scales. Stipes dense- 
ly scaly, 1/-3/ long; leaves oblong-lanceo- 
late in outline, acute, coriaceous, evergreen, 
1/-6/ long, 1-134’ wide, cut very nearly or 
quite to the rachis into entire oblong or lin- 
ear-oblong obtuse segments, glabrous or 
nearly so on the upper surface, the lower 
densely covered with gray peltate scales 
with darker centres, as are also the rachises; 
veins indistinct, unconnected and usually 
once forked. 
On trees or rarely on rocks, Virginia to Flor- 
ida, west to Illinois, Missouri and Texas. As- 
cends to 4ooo ft. in North Carolina. Widely 
distributed in tropical America. July—Sept. 
Family 6. MARSILEACEAE R. Br. Prodr. Fl. Nov. Holl. 1: 166. 1810. 
Perennial herbaceous plants rooting in mud, with slender creeping root- 
stocks and 4-foliolate or filiform leaves. Asexual propagation consisting of 
sporocarps borne on peduncles which rise from the rootstock near the leaf-stalk 
or are consolidated with it, containing both macrospores and microspores. The 
macrospores germinate into prothallia which bear mostly archegonia, while the 
microspores grow into prothallia bearing the antheridia. 
Two genera and some 45 species of wide geographic distribution. 
1. MARSILEA L,. Sp. Pl. 1099. 1753. 
Marsh or aquatic plants, the leaves commonly floating on the surface of shallow water, 
slender-petioled, 4-foliolate, Peduncles shorter than the petioles, arising from their bases 
or more or less adnate tothem. Sporocarps ovoid or bean-shaped, composed of two vertical 
valves with several transverse compartments (sori) in each valve. [Name in honor of Gio- 
vanni Marsigli, an Italian botanist, who died about 1804. ] 
About 40 species, widely distributed. Besides the following 2 or 3 others occur in Texas. 
Sporocarps glabrous and purple when mature. 1. M. quadrifolia. 
Sporocarps densely covered with hair-like scales. 2. M. vesttta. 
Dy 
lug, 
Ss 
1. Marsilea quadrifolia L,. 
European Marsilea. (Fig. 73.) 
Marsilea quadrifolia J, Sp. Pl. 1099. 1753. 
Rootstock slender, buried in the muddy bot- 
toms of shallow lakes or streams. Petioles us- 
ually slender, 2’-5’ high, or when submerged 
sometimes elongated to 1° or 2°. Leaflets mostly 
triangular-obovate, variable in outline, 3//-8/’ 
long, 2’’-6’’ wide, glabrous or rarely with scat- 
tered hairs when young, the margins entire; 
sporocarps 2 or rarely 3 on a branching peduncle 
which is attached to the petiole at its base, 
covered with short yellowish-brown hairs when 
young, becoming glabrous and dark purple 
when mature; sori § or 9 in each valve. 
Along the shores of Bantam Lake, Litchfield Co., 
Conn., whence it has been introduced into various 
parts of the country, notably into eastern Massachu- 
setts. Native of Europe and Asia. 
3 
