200 A TEXT-BOOk OF BOTANY 
loosen and uncoil; when moistened, they close around the 
spore. The coiling and uncoiling movements of these bands 
as they are wet 
c or dry entan- 
gle the spores, 
and they fall in 
clumps, a num- 
ber of them 
thus germinat- 
ing close to- 
Fic. 192.—A, a sporophyll of Eguisetum, bearing sporangia gether. 
beneath the shield-like top; B and C, spores, showing 
the unwinding of the two bands forming the outer coat. 114. Gameto- 
phyte.— When 
the spores of an Equisetum germinate they give rise to 
gametophytes that in all general features resemble those of 
the ferns; that is, they are small, green thallus bodies pro- 
ducing antheridia and archegonia. From the odspores pro- 
duced in the archegonia the large sporophyte arises, with 
its roots, rootstock, branches, leaves, and strobili. 
It is evident that, although an Equisetum does not 
seem to resemble a fern in the least, the life-history and 
the character of the alternating generations are the same. 
CLUB-MOSSES 
115. General characters.—The club-mosses often look 
like coarse mosses, as the name suggests. Some of the 
larger ones are called also ground pines, because of a cer- 
tain resemblance to miniature pines. They are slender 
branching plants, with the prostrate or erect stems com- 
pletely clothed with small leaves (Fig. 193). The larger 
and coarser forms are abundant in the Northern woods, the 
prostrate stems often trailing extensively and giving rise to 
erect branches. The more delicate forms are abundant 
in the tropics, and are very common in greenhouses as 
decorative plants. 
