2 86 SYSTEMATIC BOTANY 



blights, rusts, mildews, etc., by their effects upon the vegetation of his 

 neighborhood. Learn to know at a glance whether a given field or or- 

 chard is suffering from leaf curl, scab, the yellows, bunt, smut, mildew, etc. 

 A systematic study of mushrooms will be found very interesting from 

 both a scientific and a dietetic point of view for those who have leisure 

 to undertake it and means to expend on the rather costly literature that 

 deals with the subject. 



SYSTEMATIC BOTANY 



409. Now that some knowledge has been obtained of 

 the structure of plants, their analysis and classification can 

 be taken up with both profit and pleasure. To know the 

 place of a species in the great scheme of life, and under- 

 stand what is to be expected of it in its normal family 

 relations is necessary before we can appreciate justly its 

 adaptations to the surrounding conditions in its struggle 

 for existence. It is not advisable to spend too much time 

 in the mere identification of species, but enough should be 

 examined and described to familiarize the student with the 

 distinctive characteristics of the principal botanical groups. 



410. Botanical Terminology is in a very unsettled state at 

 present, owing to disagreements among botanists as to the 

 use of certain terms, but this does not affect the general prin- 

 ciples of classification and nomenclature. All the known 

 plants in the world, varied and multitudinous as they are, 

 numbering not less than one hundred and twenty thousand 

 species of the seed-bearing kind alone, are ranged accord- 

 ing to certain resemblances of structure, into a number of 

 great groups known as families or orders. The names 

 of these families are distinguished by the ending acece ; 

 the rose family, for instance, are the Rosacea ; the pink 

 family, Caryophyllacea ; the walnut family, Juglandacecz, etc. 



411. Genera and Species. Each of these families is 

 divided into lesser groups called genera (singular, genns\ 

 characterized by similarities showing a still greater degree 

 of affinity than that which marks the larger groups or 

 orders; and finally, when the differences between the 

 individual plants of a kind are so small as to be disre- 



