A KET BASED MAINLY UPON THE FLOWERS, 



Designed as an Aid in the Identification of the Species represented in 

 Parts I to VII, inclusive. 



EXOGENOUS PLANTS those having stems formed of bark, wood (in 

 annual layers) and pith; cotyledons two or more. 



a. Angiospermae seeds in a closed ovary. 

 b. Polypetalous petals present and distinct. 

 c. Stamens numerous, more than 10, and 



d. Calyx inferior wholly free from the pistil or pistils. 

 e. Pistils numerous and cohering in a cone-like mass. ( Magnoliacice) . 

 f. Anthers opening inward: leaves folded lengthwise in the bud (Mag- 

 nolia], pointed at both ends and 

 ff. Thick 



Glaucous beneath 51. M. GLAUCA. 



Rusty tomentose beneath 101. M. GRANDIFLORA. 



f/ 2 . Thin, green beneath 1. M. ACUMINATA. 



/ 2 . Anthers opening outward and leaves folded crosswise in the bud. 



2. LlRIODENDRON TULIPIFERA. 



e 2 . Pistils more than one, separate (or nearly so); stamens inserted on re- 

 ceptacle and filaments shorter than anthers (Anonacece) . 



76. ASIMINA TRILOBA. 



e*. Pistil solitary and 



/. One-celled, style single, flowers perfect; fruit 

 g. A drupe with stone bony (Prunus) and 

 h. Compressed, with ridged margin; calyx-lobes glandular-serrate. 



81. P. NIGRA. 



7i. 2 . Marginless; flowers in 

 . Racemes 



Terminal ; leaves deciduous 29. P. SEROTINA. 



Axillary leaves persistent 156. P. ILICIFOLIA. 



1 2 . Corymbose umbels 55. P. PENNSYLVANICUM. 



1 3 . Umbles; leaves 



Acuminate, hairy beneath 56. P. AVIUM. 



Acute, nearly smooth beneath 82. P. CERASUS. 



gr 2 . An achenium tipped with elongated style 



130. CERCOCARPUS PARVIFOLIUS. 



/*. Compound as shown by the styles and cells of ovary; leaves 

 </. Punctate with pelucid dots (Aurantiacece); stamens about 



20; fruit globose, flattened at end 103. CITRUS AURANTIUM. 



35; fruit globose- oblong, pointed 104. CITRUS LIMONUM. 



gr 2 . Not punctate. 

 h. Simple and calyx 



Valvate in the bud, deciduous (Tiliacece) stamens polydel- 

 phous (Tilia) and with 5 petal-like scales opposite the petals. 



3. TILIA AMERICANA. 



Imbricated in the bud, persistent; stamens at the base of 

 petals ( Temstrcemiacece) ; calyx simple; stamens 5-adel- 

 phous (Gordonia); leaves coriaceous, evergreen. 



102. G. LASIANTHUS. 

 7* 2 . Compound (Meliacece) 105. MELIA AZEDARACH. 



