ARTIFICIAL KEY TO THE FAMILIES. 75 



c. Leaves oblong, lanceolate, or ovate-lanceolate. 



Juice of stem milky Poppy, 97 



Juice of stem watery and colourless. 



Leaves serrated moi'e or less Rocket, 571 



Entire or very nearly so. 



Glabrous Wall-floiocr, 121 



Hoary with fine white hairs Stock, 121 



Leaves opposite. 



Stems semi-ti'ansparent Balsam, 99 



Stems opaque. 



Glaucous Pink and Carnation, 147 



Green Lychnis and Soapwort, 



143, 144 

 Viscid, especially above Petunia, 223 



Flowerless Plants. 



Plant with distinct roots or rootstocks, and leaves or 

 green branches. 



Fructification on the back of the leaf Ferns, 469 



Fructification in terminal spikes. 



Stem leafless, or with whorled branches, or with 



sheaths at the joints Horsetails, 485 



Stem clothed with abundance of small green 



leaves LycopocUum, 483 



Stem with one large leaf below the spike Adders-tongue, 476 



Fructification in terminal panicles Ferns, 476 



Fructification in the axils of minute leaves, or upon 

 the general surface of the plant. 



Thecse sessile, land plants Lycopodium, 483, Riccia, 



507 



Thecse sessile, pondside plant Pillwort, 484 



Thecse stalked. 



Opening with a lid Mosses, 488 



Opening with 4 or 8 valves Marchantia family, 50(5 



No distinct roots or rootstocks. 

 Water-plants (usually) and green (usually ) Chara and Sea-weed fami- 

 lies, 519, 529 

 Land plants, scarcely ever green. 



Usually dry and crisp Lichens, 510 



Usually spongy or watery Mushroom family , 520 



