102 HOW PLANTS ARE CLASSIFIED AND STUDIED. 
Turn now to the account of this family, and read over the descriptive marks 
given, to see if you have been led to a right conclusion. The description agrees, 
as far as it goes. Knowing the family, you now ask,— 
To what genus of this family does the plant belong? ‘The genus gives the 
principal name of the plant; so this is the same as asking, What is the plant’s 
name? Now, in every family which has several genera or kinds under it, we have 
a key to the genera, like that which we have just used under the class to find out 
the family. Try the key, then, under this family, to find out the genus. 
This key begins with a pair of lines, viz. “Climbing plants,” &c., and “ Not 
climbing,” &c. Our plant agrees with the latter. Under this, in the next rank, 
is a pair of lines, beginning with “ Pistils” (the second line of the pair is the sixth 
on p. 113). You perceive that our plant falls under the first. Under this is the 
line beginning “ Petals none.” Our flower has petals; so pass on to the other one 
of the pair, which is the fifth line on p. 113. ‘This reads “Petals present as well 
as sepals, the latter falling off early” (which agrees) ; and leads to the name of 
the genus, i. e. “ (Ranunculus) CRowFoor.” 
The first name, in parentheses and in Italic type, is the scientific or Latin name 
of the genus; the other, in small capitals, is the popular English name of the genus. 
When we have only one species to the genus, we do not in this book proceed 
farther. But there are many Crowfoots, so you next inquire, — 
What is the species? ‘Look on, till you come to the name of the genus in dark 
kétters, on p. 114. Here a few more marks of the Crowfoot genus are given; and 
then the marks of ten common species of Crowfoot follow, under several heads. We 
are supposed to have in our hands one of the two large yellow-flowered species, com- 
monly called Buttercups. Compare the specimens with the divisions marked by 
stars. It cannot belong to that with one star, for the petals are not white; it does 
belong to that with two stars, for the petals are yellow, and bear a little scale on 
the inside just above the bottom. Under this are two divisions, marked with dag- 
gers. Not growing under water, our plant belongs to that marked + +. Under 
this are two further divisions, marked ++ and ++ ++: our plant, having the “petals 
much longer than the calyx,” belongs to the second of these. 
Under this head are four species. The English name is given at the beginning 
of the line, in small capital letters; a short description follows, and the scientific or 
Latin name is appended, in Italic letters, at the end. Here the R. of course stands 
for Ranunculus. A comparison with the description will show which species it is 
