SEA-WEEDS. 



191 



Fig. 161 rep- 

 resents a species 

 of the Junger- 

 mannia compla- 

 nata^ as repre- 

 sented under a 

 magnifier, a^ a 

 plant of natural 

 size, in fruit. 5, 



the fruit magnified, showing the sheath, the pedunch 

 from it, and the theca at toj), not yet burst. (?, the open cap- 

 sule splitting and discharging the seeds. cZ, the theca empty, 

 showing its lour valves. 



288. Order Algce includes the sea-weeds and green mosses. of 

 vegetable cells seen floating on stagnant water, and sometimes 

 vulgarly called frog-spittle ; they are almost always aquatics ; 

 generally green or reddish. One genus of this family is the 

 Fucics. The Fucus natans^ sometimes called the gulf-weed, 

 is very abundant in the Gulf of Florida, and is found in vari- 

 ous parts of the ocean, forming masses or floating fields 

 many miles in extent. The plant seems to possess no distinct 

 root, though it perhaps originally vegetated on some sea-beaten 

 shore from whence it was by accident thrown upon the ocean's 

 wave. The Fucus giganteus has a frond of immense length. 

 Fig. 162-^ repre- 

 sents three kinds 

 of Fuci.f a is 

 Fucus nodosus 

 (knobbed fucus) ; 

 this has forked 

 fronds; the knobs 

 appearing in the 

 fronds are air- 

 bladders, which 

 render the plant 

 buoyant upon the 

 water ; it is often more than six feet in length. J, Fucus ve- 

 siculosxis (bladder fucus) ; here the air-bladders are mostly axil- 

 lary, and at the sides of the midrib ; in some parts of Lapland 



. it is boiled with meal, and given for food to cattle. <?, Fucus 

 serratus ; it has a beautiful serrate frond. The Fuci wlien 

 burnt aflbrd an impure soda, called help. 



289. Order Lichenes. — According to Linnaeus, \hQ fifth Order 

 of Cryptogamous plants contains tfie Lichens ; these are various 



* See also Appendix, Plate viii., Figs. 8, 9, 10, 11. 



t Fuci is the plural of Fucus. 



3. Sea-weeds— Fuci— Gulf-weed— Three Itinds of Fuci.— 389. Lichens. 



