36 



ROSACEA 



[CH. 



Another instructive series of fruits is afforded by the 

 natural order Rosacea?. 



The simplest form here is the Follicle which may be 

 single (Neillia, Stephanandra) or grouped (Spiraea) or 

 joined below and so forming an imperfect Capsule 

 (Sibircm, Lindleya) or completely fused into a capsule 

 until dehiscence {Exochorda, Fig. 33). 



In Ei'iogynia and Quillaia (Fig. 34) the carpels open 

 by both valves, and are practically Legumes, at first more 

 or less joined by their ventral sutures below into an im- 

 perfect Capsule. 



Next we find forms with only one seed in each carpel, 

 which is indehiscent i.e. an Achene (e.g. Holodiscus). 



Next we have a series of forms in which the single 

 carpel obtains a fleshy mesocarp and more or less bony 

 endocarp, as in the Drupes of the Almond (Fig. 35) 

 where the mesocarp is as yet only leathery, and retains 



Fig. 35. Almond, Primus Ainygdalus, Stokes. A, drupe. B, drupe 

 opened to show the stone (E and P). 



the power of dehiscing partially Plums, Cherries, &c. 

 (Fig. 22). In Prinsepia the endocarp is leathery, and 

 in some Chrysobalanoideaa the mesocarp is mealy, while 



