6 



SYSTEMATIC BOTANY. 



Cl 



genus Scoliopus. Turning to the description of the only species de- 

 scribed, we find it satisfactory. Upon referring to the Glossary of 

 Generic and Specific Names in the back part of the book, we find why the 

 plant was named Scoliopus Bigelovii- 



58. Special Directions. Do not decide 

 anything concerning the ovary by the outside 

 appearance of the flower only, but carefully 

 examine it. Otherwise you may even mis- 

 take an inferior ovary for a pedicel, or a 

 calyx tube" for a peduncle. For example, 

 some Onagraceoz have slender sessile ovaries; 

 CEnothera ovata has the ovaries under ground 

 in the axils of radical leaves, and the slender 

 calyx tubes exactly mimic scapes. To deter- 

 mine whether an ovary is inferior ov.snpe.rior, 



it is often necessary to cut the flower verti- 



11 1-1 -, ,-, i TT 61. A flower of" wmppiea, magnmea, cnt acnrn 



cally through the center, as is shown in Fig. through the center, showing the partly inferior 

 represents the partly inferior ovar y a ud the iutrorse anthers. 

 ovary of Whipplea modexta. (Fig. 62 shows a few flowers, natural size.) 

 The number of cells in the ovary may be shown by cutting across the 

 middle. To determine whether the placenta is central or parietal, it is best 

 to get the partly grown fruit (pods). If you find the seeds growing fast 

 to the sides of the pod the placenta is parietal. The number of ovules in 

 the ovary of a Lupine flower may be easily seen by scraping off the downy 

 coating of the sides and holding it up to the light. 



59. The side of an anther, from which the pollen escapes, is called its face. If this 

 is toward the pistil the anther is introrse (Fig. 61); if toward the corolla, extrorse (Fig. 

 60.) Wheu the stamens of a gamopetalous flower are inserted low down it is often diffi- 

 cult to tell whether they are opposite or alternate, with the corolla lobes. In such cases 

 you can generally decide by tracing the midveins of the corolla lobes downward. If they 

 go between the bases of the filaments, the latter must be alternate with the lobes of the 

 corolla. 



In the Order Cruciferce, you have frequently to decide whether fa 

 an embryo is incumbent or accumbent. Fig. 63 shows at a an incum- a 

 bent embryo; at b an accumbent embryo. 



