A KEY, BASED MAINLY UPON THE FLOWERS, 



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

 Parts I to VI inclusive. 



Angiospermae seeds in a closed ovary. 

 . 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 

 g. Thick 



Glaucous beneath 51. M. GLAUCA. 



Rusty tomentose beneath 101. M. GRANDIFLORA. 



gr 2 . Thin, green beneath 1. M. ACUMINATA. 



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



2. LlRIODENDRON TULIPIFERA. 



e 8 . Pistils more than one, separate (or nearly so) stamens inserted on re- 

 ceptacle and filaments shorter than anthers (AnonacecB). 



76. ASIMINA TRILOBA. 

 6*. 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 

 i. Racemes terminal 29. P. SEROTINA. 



1 2 . Corembose umbels 55. P. PENNSYLVANICUM. 



1 3 . Umbels; 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. 



/ 8 . Compound as shown by the styles and cells of ovary; leaves 

 g. Punctate with pelucid dots (AurantiaceoB)', stamens about 



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



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



gr 9 . Not punctate. 

 h. Simple and calyx 



Valvate in the bud, deciduous (Tiliacew) stamens polydelphous 

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



3. TILIA AMERICANA, 



