184 HOW TO STUDY PLANTS. [LESSON 30. 



Our plant clearly belongs to the first subclass. The second subclass 

 comprises only Piues, Spruces, Cedars, and the like. 



530. We have no less than 110 orders under this subclass. To 

 aid the unpractised student in finding his way among them, they are 

 ranked under three artificial divisions ; the Polypetalous, the Mono- 

 petalous (page xx), and the Apetalous (page xxi). The flowers 

 of the last are destitute of any corolla ; those of the second have the 

 petals more or less united into a tube or cup ; the first alone has a 

 corolla of separate petals. Our plant accordingly belongs to the 

 POLTPETALOUS division. 



531. This division comprises fifty-four orders in the Northern 

 United States. The Artificial Key analyzes them by certain easy 

 characters, arranged, as we perceive, under a series of headings, 

 which lead by successive steps down to the order. The first is 

 marked A, and has its counterparts B and C on the next page. It 

 relates to the number of the stamens. In our plant the stamens are 

 more numerous than the petals : so it falls under the head A. 



532. The head under this, marked 1, with its counterpart on 

 the next page, marked 2, relates to the calyx, whether free (269), 

 or coherent with the ovary (271). If we have any doubt about this, 

 the best way is to split the blossom through from top to bottom, just 

 as in Fig. 358. Here the calyx is entirely and widely separate 

 from the pistils ; so we refer our plant to the head No. 1. 



533. The next step under this is marked with a star ( * ), and has 

 its alternatives on the next page, marked one with two stars, the 

 other with three. It directs us to examine the stamens, and see 

 whether they grow directly on the receptacle (that is, are hypogy- 

 nous, 269), or are united with the base of the petals, or else are 

 borne on the calyx. The first is plainly the case in the present in- 

 stance ; so we read on down the page. 



534. The next line reads, " Pistils numerous, but cohering over 

 each other on a long receptacle." In our plant they are numerous, 

 but are entirely separate, only crowded together. We pass therefore 

 to the next line, which reads, "Pistils several, immersed in the upper 

 surface of a top-shaped receptacle " ; which by no means accords 

 with our plant, So we proceed to the third line, which does accord, 

 viz. : " Pistils more than one, wholly separate and distinct." The 

 six lines which follow this, and which are set further in, rank under 

 it. The first two give an alternative, relating to the length of the 

 filaments. Our plant falls under the second, the " filaments " being 



