ARTIFICIAL KEY TO THE 

 FAMILIES 



N.B. This Key has been adapted mainly from that in Sir D. Prains 

 ' Bengal Plants,' with the author's kind permission. The necessary 

 modifications make it applicable only to the present flora. Dr. J. 

 Hutchinson's ' Families of Flowering Plants ' has also been of help. 



Ovules naked, not enclosed but borne on an open carpel, devoid of 



stigma. Wood usually with no true vessels (except in Gnetaceae) ; 



cotyledons 2-many ; flowers always 1 -sexual (Gymnospermae) : 



Large climbers ; leaves simple ; flowers monoecious, whorled in 



the axils of bracts on solitary or panicled spikes ; perianth present 



CXLIII. GNETACEAE. 



Trees or shrubs ; flowers in cones or quasi cones ; perianth : 

 Leaves simple, scale-like, needle-like or flat and lanceolate, up to 



8 in. long CXLIV. CONIFERAE. 



Leaves pinnate, resembling palm leaves, 3-9 ft. long ; petioles 



more or less spiny CXLV. CYCADACEAE. 



Ovules enclosed in the carpels, crowned by a style and stigma. Wood, 

 when present, consisting of true vessels ; cotyledons 1-2 (ANGio- 

 SPEBMAE) : 



Stem with a central pith surrounded by one or more concentric 

 rings of woody vascular tissue enclosed in a separable bark ; leaves 

 usually articulated on the stem and usually with branched or 

 reticulated veins ; cotyledons usually 2, opposite, the young stem 

 arising between them (Dicotyledones) : 



Calyx and corolla usually both present ; flowers mostly bisexual 

 (Dichlamydeae) : 



Petals usually free ; stamens often numerous (Polypetalae) : 

 Stamens hypogynous, arising apart from the calyx direct 

 from the receptacle or from a disk crowning the pedicel ; 

 segments of calyx usually free (Thalami florae] : 



Sepals usually imbricate in bud ; if valvate, then sepals 

 free, leaves opposite, stamens many and fruitlets separate ; 

 or with paripinnate leaves and arillate seeds : 



