1957] 



ANATOMY OF GUAYANA MUTISIEAE 



453 



DRAWING CONVENTIONS 



All the species in this study are discoid (although the flowers of Glossarion 

 are ligulate in form from the standpoint of gross morphology). The accompanying 

 drawings of floral parts, therefore, represent the venation of a particular disk 

 flower. Although the parts of a flower have been separated for purposes of draw- 

 ing, they may be interpreted as being intercontinuous. This separation was 

 .necessary because of the great complexity of venation. The proportions of the 

 parts and the locations of veins within them reflect as accurately as possible 

 the actual condition in the material studied, but an effort has been made to 

 render the drawings simpler by avoiding the crossing of bundles over one another, 

 such as is seen when viewing a given preparation of a style or achene. In species 

 where variable numbers of lesser veins may be found in flowers, a more compli- 

 cated flower is usually represented, and simpler conditions, if they were found 

 to occur, are described in the text. 



The corollas, which appear first in each figure, are shown to be cut the 

 length of the tube and spread flat. This cut, which corresponds to the manner in 

 which whole mounts of corollas were prepared, is made slightly to one side of 

 the adaxial sinus of the corolla tube, and is indicated by the portion of the 

 corolla outline drawn in lines broken at wide intervals. Stamen traces are indi- 

 cated by lines broken at narrow intervals* Because stamen traces may vary in 

 length depending on the state of development of the flower, they are of interest 

 only in respect to the point in the corolla tube at which they depart (indicated 

 by a curving away from the adjacent veins) and in respect to their union with 

 corolla veins (mostly in the achene, just beneath the base of the corolla). For 

 reasons of simplification, stamen traces are not shown in the drawings of entire 

 achenes, but they are shown in the transection of the corolla base in each figure. 



Styles and achenes are viewed laterally, i.e. in the position in which they 

 would be seen in a radial section of a head. Thus the two stigmatic branches at 

 the apex of a style, which are disposed adaxially and abaxially, are shown at 

 right and left in each drawing. Bundles of the style which continue into the 

 achene are extended beyond the outline of the style. The styles drawn do not 

 include the nectary, which would be beneath the base of the style in the taxa 

 in which a nectary is present. 



The Mutisieae investigated in this study have two series of bundles in the 

 achene. The exterior bundles are connected above with veins of the corolla or 

 terminate freely in the top of the achene; the interior bundles are continuous 

 with the style bundles or terminate freely in the upper portion of the achene. 

 These two reries of bundles are considered to represent perianth and carpellary 

 bundles respectively, and a distinction is consequently made. The exterior 

 bundles of the achene are shown in unbroken lines; the interior bundles and 

 ovule trace are represented by broken lines. In many of the drawings, these two 

 sets of bundles are shown in complementary pairs of drawings, because to show 

 both of them in a single drawing would be too complicated. Since the style bundles 

 are a continuation of the interior bundles, they are shown in broken lines in the 

 achene drawings. Where the two sets of bundles are separate, portions of the 

 exterior bundles are shown on the carpellary bundle drawing if interior bundles 

 connect with them, and may be distinguished from the interior bundles since 

 they are drawn in unbroken lines. Portions of the bundle or bundles which ex- 

 tend from the achene into the receptacle are shown in order to indicate the nature 

 of vascular connections between these two structures. 



A series of selected transections, starting from the corolla base and going 

 to the achene base, is shown for most of the figures. This series is intended to 

 show the disposition of exterior and interior bundles, and to aid in interpreting 



