254 BOTANY OF CROP PLANTS 



The staminate inflorescences are long, cylindrical catkins. 

 They soon fall. The calyx of the staminate flowers is deeply 

 divided into four rounded lobes. The three or four stamens 

 are inserted at the base of the calyx, beneath the rudimentary 

 pistil. The filaments are thread-like, inflexed in the bud 

 and uncoil like a spring at the moment of anther dehiscence. 

 The two-celled anthers open lengthwise and shed their 

 pollen toward the inside of the flower (introrse dehiscence). 



The pistillate inflorescences are short, dense catkins. The 

 flowers in these have a deeply four-lobed calyx, the two outer 

 lobes being the broader. All the calyx lobes are persistent, 

 become fleshy, and enclose the ovary in the fruit. The 

 sessile ovary possesses one cell, and a single style divided 

 almost to the base into two very slender, hairy stigmas. 



Fruit. — Each ovary develops into a nutlet bearing rem- 

 nants of the styles at the tip and enclosed by the thickened, 

 juicy calyx lobes. There is a single seed within each fruit. 

 However, the mulberry "fruit" as commonly understood, 

 is not a single drupe-Uke structure, as given above, but an 

 aggregate of these, i.e., an entire pistillate flower cluster. 

 The single fruits are very much crowded together, making up 

 a collection, which commonly goes by the name "mulberry." 



Other "Mulberries." — The so-called paper mulberry 

 (Papyrus papyrif era), Sinsitiyeoi eastern Asia and now planted 

 for ornament in many parts of eastern and southern United 

 States, may be easily distinguished from the true mulberries 

 (Morus) by its non-edible globular fruit and the occurrence 

 of its pistillate flowers in heads. In some sections of the 

 country, the "flowering raspberry" {Rubus odoratus) is 

 confused with and often called a "mulberry." It is true that 

 the fruit of this has some resemblance to a mulberry "fruit," 

 but instead of bearing its single drupe-like fruits along an 

 axis, the true drupes of the raspberry are borne on a receptacle. 



