112 



THE STAMENS. 



[lesson 17. 



Triadefpkoits, in three sets or 2>art'els, as in the common St. Johns- 

 wort ; or 



Polyadelphous, when in more numerous sets, as in the Loblolly 

 Bay, where they are in five clusters. On 

 the other hand, stamens are said to be 



Syngenesious, when united by their an- 

 thers (Fig. 229, 230), as they are in Lobelia, 

 in the Violet (slightly), and in what are 

 called compound Jlowers, such as the Thistle, 

 Sunflower, Coreopsis (Fig. 220), and Suc- 

 cory (Fig. 222). In Lobelia, and in the 

 Squash and Pumpkin, the stamens are 

 united both by their anthers and their filaments. 



287. Their Number in the flower is sometimes expressed by terms 

 compounded of the Greek numerals and the word used to signify 

 stamen ; as, monandrous, for a flower having 



only one stamen ; diandrous, one with two 

 stamens ; triandrous, with three stamens ; te- 

 trandrous, with four stamens ; pentandrous, 

 with five stamens ; and so on, up to pohjan- 

 drous (meaning with many stamens), wlien 

 there are twenty or a larger number, as in a 

 Cactus (Fig. 197). All such terms may be 

 found in the Glossary at the end of the book. 



288. Two terms are used to express particular numbers with mi- 

 equal length. Namely, the stamens are didynamous when only four 

 in number, two longer than the other two, as in the Mint, Catnip, 

 Gerardia (Fig. 1J94), Trumpet-Creeper, &c. ; and tetradynamous, 

 when they are six, with four of them regularly longer than the 

 other two, as in Mustard (Fig. 188), and all that family. 



289. Their Parts. As already shown (233), a stamen consists of 

 two parts, the Filament and the Anther (Fig. 231). 



290. TIlC Filament is a kind of stalk to the anther : it is to the 

 anther nearly what tlie petiole is to the blade of a leaf. Therefore 

 it is not an essential part. As a leaf may be without a stalk, so 

 the anther may be sessile, or without a filament. When present, 



FIG. 207. Diadelphous stamens of the Pea, &c. 228. Monadelplious stamens of tlio 

 Lupine. 



FIO. 229. Synccnesioiis stamens of Coreopsis (Fig. 220, a), &c. 230. Same, witli tin 

 tube of anthers split down on one side and sjiread open. 



