LESSON 32.] HOW TO STUDY PLANTS. 193 



LESSON XXXII. 



HOW TO STUDY PLANTS : FURTHER ILLUSTRATIONS. 



.560. THE foregoing illustrations have both been taken from the 

 subclass Dicotyledons. We will take one from Monocotyledons, 

 selecting a very common and beautiful Lily-like plant of the plains 

 and foot-hills, the " Beautiful Grass," or " Sego" of the natives. 



561. With specimens in hand, and the Manual open at the Ana- 

 lytical Key (p. ix.), seeing at once that the plant is a PH^ENOGAM, 

 and also an ANGIOSPERM, we proceed to determine the subclass. 

 Nothing in Subclass I. accords with our plant, while its parallel- 

 veined leaves and flowers in threes agree exactly with Subclass II., 

 MONOCOTYLEDONS (p. xv.). Dissection of a matured seed would 

 onfirm this decision by revealing an embryo with but one coty- 

 ledon. 



562. The superior ovary at once fixes our choice upon the group 

 B, " Ovary superior or nearly so," etc. 



Five propositions are now presented, unusually dissimilar in 

 their wording, but well characterizing the groups to which they 

 lead. Beginning with the last, the stems of our plant are not 

 hollow, and there are neither sheaths nor glumes. The fourth 

 group does not answer, on account of its calling for " no evident 

 perianth." In the third, the perianth is glumaceous ; in the second, 

 the carpels are distinct and the plants mostly aquatic, which plainly 

 is not the case with ours. Choice must thus be mttde of the first 

 group, with " Carpels united into a compound ovary : perianth 

 corolla-like : terrestrial plants." 



Under this, the choice between " woody climbers " and " herbs " 

 is easily made. Under the latter, the fact that our plant has a 

 perianth with divisions colored somewhat alike and neither of them 

 deliquescent, and that the stems come from a bulb, determines the 

 selection of the order LILIACE^, No. 79, p. 345. 



563. Under this order we find 21 genera, arranged in three 

 great groups, I., II., and III. The deciduous perianth, hypogy- 

 nous stamens with extrorse anthers, and absence of styles, would 

 lead us to choose group II., under which the bulb or corm and 

 capsular fruit would decide in favor of the group marked with 

 a single asterisk. 



