194 HOW TO STUDY PLANTS. [LESSON 32. 



species will be met with, having dull-green and petioled leaves 

 rounded at the base, and rather narrow, wavy, white petals, marked 

 with pink or purple stripes at the base : this the student will refer 

 to T. erythrocarpum. But the species principally found in the east- 

 ern parts of the country has a short peduncle recurved under the 

 leaves, so as nearly to conceal the much less handsome, dull white 

 flower : this, it will be seen, is T. cernuum, the Nodding Trillium 

 or Wake Robin. 



565. Whenever the student has fairly studied out one species of 

 a genus, he will be likely to know the others when he sees them. 

 And when plants of another genus of the same order are met with, 

 the order may generally be recognized at a glance, from the family 

 resemblance. For instance, having first become acquainted with the 

 Convolvulus family in the genus Calystegia (555), we recognize it 

 at once in the common Morning- Glory, and in the Cypress- Vine, 

 and even in the Dodder, although these belong to as many different 

 genera. Having examined the common Mallow (552), we immedi- 

 ately recognize the Mallow family (Malvaceae) in the Marsh-Mallow, 

 sparingly naturalized along the coast, in the Glade Mallow, and the 

 Indian Mallow, in the Hibiscus or Rose-Mallow, and so of the rest : 

 for the relationship is manifest in their general appearance, and in 

 the whole structure of the flowers, if not of the foliage also. 



566. So the study of one plant leads naturally and easily to the 

 knowledge of the whole order or family of plants it belongs to : 

 which is a great advantage, and a vast saving of labor. For, 

 although we have about one hundred and thirty orders of Flowering 

 Plants represented in our Botany of the Northern States by about 

 2,540 species, yet half of these species belong to nine or ten of these 

 orders ; and more than four fifths of the species belong to forty of 

 the orders. One or two hundred species, therefore, well examined, 

 might give a good general idea of our whole botany. And students 

 who will patiently and thoroughly study out twenty or thirty well- 

 chosen examples will afterwards experience little difficulty in determin- 

 ing any of our Flowering Plants and Ferns, and will find the pleasure 

 of the pursuit largely to increase with their increasing knowledge. 



567. And the interest will be greatly enhanced as the student, 

 rising to higher and wider views, begins to discern the System of 

 Botany, or, in other words, comprehends more and more of the Plan 

 of the Creator in the Vegetable Kingdom. 



