APPENDIX OX PRACTICAL WORK. I 5 I 



6. Andrcecium. — When the stamens are double the number of the 

 petals, both the typical whorls are present (p. 82). If equal in number, 

 the inner stamens have generally been suppressed (see above, formulae 

 for carrot and grasses). More rarely (see formula for primrose) the 

 outer stamens are suppressed. It is easy to tell which whorl is left, for 

 the outer stamens alternate with the petals, while the inner ones are 

 superposed to them. If the stamens are fewer than the petals, they 

 usually represent part of the outer whorl (see formula for orchis). 



7. Gynceciwm. — This is typically composed of two whorls of carpels, 

 but do not put o to represent the usually suppressed whorl, as it is 

 not possible in many cases to tell easily which whorl is suppressed. 

 Thus the formula for gorse is properly (p. 103; — 



Ca (5), Co 5, An (5 4- 5), Gn 1 +0, 



but it is enough to write Gn 1. 



Superior and Inferior. — If, as in hypogynous and perigynous flowers, 

 the ovary is free, term it superior ; if, as in epigynous flowers, adherent 

 to the cup-shaped receptacle, inferior. 



Placentation.—lu most cases a transverse cut will show this. If not, 

 divide another specimen longitudinally. This will show erect and 

 ascending ovules. Determine the number of ovules if a few only are 

 present. When they are very numerous, write indefinite (00 ). 



8. Xectaries. — These vary immensely in size, nature, and position. 

 They may be mere points, streaks, or surfaces where nectar is excreted, 

 but, on the other hand, may be conspicuous projections. They are so 

 placed that the stigma, or anthers, or both, must be touched before an 

 insect can reach them. The chief situations are : — (a.) on receptacle 

 (wallflower, willow, mignonette) ; (b.) as a spur to calyx (garden nas- 

 turtium) ; (c.) on corolla, as glandular spots (buttercup), or spurs (lark- 

 spur) ; (d.) on andrcecium (pansy, fig. 51) ; (e.) on ovary (dead nettle). 



9. Protection and Pollination. — Note characteristics of wind-pollinated 

 and insect-pollinated flowers (pp. 115, 118). Do not immediately con- 

 clude that an inconspicuous flower is wind-pollinated, for it may make np 

 for want of brilliancy by the possession of nectar (e.g., willow and lime; 

 or scent (e.g., lime). If flowers are present in all stages, it is easy to 

 determine whether proterandry or proterogyny obtains. The stamens 

 will be dehiscing, in the former case, in very young flowers ; vice versa in 

 the latter case. 



VIII. Fruits and Seeds. — First master the main divisions of the 

 table on pp. 136-139, and then attack the sub-divisions, examining for 

 yourself as many of the examples as you can get. For dehiscence very 

 ripe fruits are necessary. 



Spurious fruits will give little trouble. All the common kinds art' 

 described on pp. 136-139. 



Arrangement of seeds in the fruit is determined like that of ovules in 

 the ovary (see above). 



For the structure of seeds examine the types described on pp. 

 132-134. 



IX. Classification. — First determine the sub-division, class, sub- 

 class, and series, by means of the following table. Remember that 

 here are no sharp boundary-lines in Nature, so that a plant need not 



