190 HOW TO STUDT PLANTS. [leSSON 31. 



at the three sections, marked with stars. The second answers to 

 our plant; and the annual root, pointed sepals, and blue petals deter- 

 mine it to be the Common Flax, Linum dsitatissimum. 



550. By the Manual, the same plant would be similarly traced, 

 along a somewhat different order of steps, down to the genus on 

 p. 104, and to the species, which being a foreign cultivated one, and 

 only by chance spontaneous, is merely mentioned at the close. 



551. After several analyses of this kind, the student will be able 

 to pass rapidly over most of these steps ; should ordinarily recog- 

 nize the class and the division at a glance. Suppose a common Mal- 

 low to be the next subject. Having flowers and seeds, it is Phseno- 

 gamous. The netted-veined leaves, the structure of the slem, and 

 the leaves of the flower in fives, refer it to Class I. The pistils, of 

 the ordinary sort, refer it to Subclass I. The five petals refer it to 

 the Polypetalous division. Turning to the Key in the Field, Forest, 

 and Garden Botany, and to the analysis of that division, commencing 

 on p. 14, the numerous stamens fix it upon A, under which the 

 very first line, " Stamens monadelphous, united with the base of 

 the corolla; anthers kidney-shaped, one-celled," exactly expresses 



-the structure of these organs in our plant, which is thus determined 

 to be of the Mallow Family, — for which see page 70. 



652. After reading the character of the family, and noting its 

 agreement in all respects, we fix upon § 1, in which the anthers are 

 all borne at the top, and not down the side of the tube of filaments. 

 We pass the subdivision with a single star, and choose the alternative, 

 with two stars, on account of the ring of ovaries, &c. ; fix upon the 

 division -•-, on account of the stigmas running down one side of the 

 slender style, instead of forming a little head or blunt tip at their 

 apex ; and then have to choose among five genera. The three 

 separate bracts outside of the calyx, the obcordate petals, and the 

 fruit determine the plant to be a Malva. Then, referring to p. 71 

 for the species, the small whiti-^h flowers point to the first division, 

 and a comparison of the characters of the two species under it, 

 assures us that the plant in hand is Malva rotundifolia. 



553. For the sake of an example in the Monopetalous Division, 

 we take a sort of Morning-Glory which is often met with climbing 

 over shrubs along the moist banks of streams. Its netted-veined 

 leaves, the sepals and the stamens being five, — also the structure of 

 the stem, if we choose to examine it, ancl the embryo with two leafy 



