COTYLEDONS AND LEAVES OF CERTAIN PAPILIONACEAE 241 



Sialics of Cotyledons and Leaves. The cotyledons are sessile 

 in most of the plants studied but they are stalked in Psoralea hypo- 

 gaea^ Glycyrrhisa lejoidota, TrifoUum dasypfvyllum and Petaloste- 

 mon candidus. In these four cases a comparative study was made 

 of the anatomy of the stalks of the cotyledons and foliage leaves. 

 Great differences were observed in all cases. The stalk of the 

 cotyledon is not so cylindrical as that of the leaf (Figs. 1 and 3). 

 The vascular tissue is placed near the center of the stalk, in a single 

 bundle, or in two which are close together. In the leaf-stalk there 

 are three or five bundles (Figs. 2 and 4), arranged in a partial 

 circle. The writer has previously^') noted just this same difference 

 between the stalks of cotyledons and leaves in Delphinium. 



Epidermal Cells. The epidermal cells, seen in surface view, 

 sometimes have a very wavy outline (Fig. 6). This is especially the 

 case with the foliage leaves. In the cotyledons cells with this wavy 

 appearance occur in only a few species. More usually the walls are 

 nearly straight (Fig. 5). The following plants conform to the gen- 

 eral rule just stated: Astragalus crassicarpus^ Astragalus racemo- 

 sus, Rohinia pseudacacia, Amorpha canescens, Aragallus deflexus^ 

 Aragallus spicatus, Petalostemon camdidus., Hedysarimi mackenzli, 

 and Glycyrrhiza lepidota. In the following plants there is some- 

 times a tendency for the respective parts to be like those named 

 above, but more usually the epidermis of both the leaves and cotyle- 

 dons is wavy: Astragalus adsurgens, A. caroliniaiius, A. flexuosKS, 

 A. hypoglottis^ Psoralea hypogaea. Trifoliurfi dasyp}hyllum and 

 Lupinus pusillus have the epidermis similar in the leaf and cotyle- 

 don but in this case the cells are not wavy. 



Stomata. There are no stomata on the upper surface of the leaf 

 in Pohinia pseudaoacia and Amorpha canescens, thouo-h they are 

 present on both surfaces of the cotyledon. All other plants exam- 

 ined have stomata on both surfaces of leaves and cotyledons. 



Trichomes. No trichomes were found on any of the cotyledons 

 studied. It must not be supposed from this statement that they are 

 never found on cotyledons for they are present on the cotyledons of 



(') Ramaley. The Seed and Seedlingof the Western Larkspur. Minn. Bot. Stud. 3:417. 1900. 



