Ee ee er ye 
THE STRUCTURE OF PLANTS. 15 
rked. Sometimes it is expanded into a wing, and at others, as in the 
Milkweed, furnished ee tuft of hairs which serve to waft it from 
place to place The mark left by the separation of the peed stall or 
Paniculus is called Ae ‘Hitom, which is conspicuous in the Bean and 
Horse-chestnut. 
§3. SysTEMATIC Borany i is that branch of the ’ science which groups 
toget ether Individual 
plants that are so much like each other that they se be conceived to 
he head of Species. Plants 
ities fi 
which our cultivated plants furnish numerous examples. Those species 
which have many points of resemblance though differing i in minor char- 
acters, are grouped together in Genera, and genera again are collected 
into Families or Orders, these into Cldeass a upon re dif. 
ferences in the structure of the embryo, stem, &c. The next group in 
—— — “ahered is that of Series, where the whole round avi so 
spars 0 great series, the one comprising the Flowering and 
the Mtoe th the ‘Flossie Plants. 
54. In the ce of plants, ma account given of the Order should © 
apply to all the genera incl proaeee that of the Genus should include 
the important skesmacters: of all Seapets it comprises ; and that of a 
Species should present those silat which distinguish it it from other 
pecies in the same Genus. 
watt e names given to plants are double, rate rp to the surname 
baptismal names of persons. The nameo ofthe ee i placed et 
followed by that of the species; the latter is usually in t 
orm. 
course all the lants that one meets with will not be found i in 
ten found — 
55: 
this eon: it it being i inten 
in cultivated sec In order the name and deseri ription of any 
y : 
r, at any rate, it may be ascertained gow ig ie cut across — 
stat: it it be an exogenous stem, then it mG 
wheter the corolla is present, and if a whethor it is composed of 
many pieces or is a more or less entire single 
being settled, a reference to the Key and a tee patience will soon nes ae 
the re Bent.) is, to which class to refer it; this is usually indicated by 
