A GENERAL SYSTEM OF FLORAL DIAGRAMS. 



JOHX H. SCHAFFNER. 



Diagramatic representations of flowers are of great con- 

 venience in assisting one's memory in respect to floral structions, 

 especially when comparative and evolutionary studies are 

 undertaken. Such diagrams have been in use for a long time 

 and are found in most botanical text books and systematic 

 works. However, as usually constructed they are rather 

 vague and of various designs, which makes it difficult to employ 

 them in any exact way. The writer has devised a system by 

 which most of the essential structures of any flower may be 

 represented by a single transverse diagram, which at the same 

 time indicates in a general way the degree of advancement of 

 the flower in the evolutionary series. 



There are five general types of flowers which call for definite 

 diagramatic representation, as follows: 



1. Hypogynous flower, as in the lily. 



2. Perigynous flower with a free hypanthium, as in the rose. 



3. Perigynous flower with adnate hypanthium, as in the 

 apple. 



4. Epigynous flower without hypanthium, as in the 

 honeysuckle. 



5. Epigynous flower with hypanthium, as in the evening 

 primrose. 



The various signs used are as follows: carpel, a small circle 

 (Fig. 1 a) ; vestigial carpel, the same in black (Fig. 1 b) ; axis 

 of inflorescence, a circle with a dot in the center (Fig. 1 c) ; 

 stamen, a pair of circles or figure eight without a line through 

 the center if the anther has but two microsporangia or with a 

 line through the center if it has four microsporangia (Fig. 1 d) ; 

 vestigial stamen, the same in black (Fig. 1 e) ; united carpels, 

 a large circle with radii to represent the partition walls, (Fig. 

 1 f) ; united carpels forming a unilocular ovulary, a similar 

 circle with points on the inside to represent the place of union 

 of two contiguous carpels (Fig. 1 g) ; sepal, a curved line, 

 thickened in the middle (Fig. 1 h) ; petal, a curved line thickened 

 in the middle and with a prominent point (Fig. 1 i). A necter 

 pit or spur is represented as shown in Fig. 1 j. Bracts are 



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