180 CLASS GYNANDRIA. 



class are poisonous ; for though milky plants ai'e generally so, those of this class arc 

 exceptions. The lettuce contains a narcotic principle, and opium may be made 

 from it. The dandelion, thoroui^hwort, chamomile, and wormwood, with many 

 other plants of thia class, are valued for medicinal properties. The Coynpositce arc 

 abundant in our own country, and the botanical student can never find dilhculty in 

 procuring specimens of this natural order. In commencing botanical studies with 

 the flowers of spring, nature gradually presents us with those that are more and 

 more difficult to investigate. The Composite bloom mostly in the latter part oi 

 the season. Being previously prepared by a knowledge of the general principles 

 of classification, and observations of plants, this great natural order may be studied 

 with satisfaction ; whereas, if a course of botanical study were to be commenced 

 with these plants, the student would find himself thrown amidst a chaos of facts 

 with no clew to their arrangement. 



LECTURE XXXY. 



GYNANDEIA, STAI^IENS ADHERING TO THE PISTIL. 



267. We shall now examine a class in which an entirely 

 new circumstance from any yet considered, is regarded as form- 

 ing its essential character : this is the situation of tJie stamens 

 ^ijpoii tlie pistil I the stamens adhering to that organ. In some 

 cases the stamens proceed from the ovary, in others from the 

 style. There is sometimes difficulty in deciding as to the num- 

 ber of stamens, for they are not here, as in other classes, distinct 

 organs, but in some cases mere collections of glutinous pollen, 

 called pollinia. The column formed by the union of the sta- 

 mens to the pistil is called a gynostaniiim^ from gune^ pistil, and 

 a7ier^ stamen. 



268. Order Monandrla, one stamen. — The orders in this class, as in Monadelphia 

 and Diadelphia, depend on the number of stamens or pollhiia. The first order 

 contains such plants as have but one stamen, or two masses of glutinous j)ollen, 

 equal to one stamen ; this order is divided into sections, with reference to the man- 

 ner in ichich the anther is attached to the style ; wliether easily separated, whether 

 the anther coheres to the top of the stigma, and also to the shape of the masses of 

 pollen which are called the anther. 



269. The type of the natural order Oi'diideaceoi is the orcMs 

 genus, consisting of many species of perennial plants which 

 grow in shady, moist places ; some are parasites, adhering to the 

 bark of trees by their fleshy, tuberous stems, and fibrous roots. 

 The corolla shows a division into six parts as in lilies, but these 

 are of different forms, and in several combinations; five of 

 these parts are always external, but frerptently in two ranges, 

 as in orchis, where the three external resemble a calyx ; and 

 there are then two internal divisions like petals, closing together 

 beneath one of the external segments, so as to resemble a hood 

 or helmet. The sixth segment or lip (for these flowers always 



ffi. Plants of this class valued for medicinal properties— Found in the latter part of the season.— 2f)7. 

 Clnss G-nandria — 2C<?. 1st order. — 269. Natural ordar Orchidacere. 



