362 The Mulberries 



bark and roots of some are ven,' yellow and are used as dyestuff, and the wood is 

 valuable as lumber. 



They have a milky sap. The leaves are alternate, membranous, 3-nerved, 

 often deeply lobed, and deciduous. The flowers appear in early spring in the 

 axils of the lower leaves, on different branches (monoecious), or rarely on different 

 trees (dioecious). The staminate flowers are in elongated cylindric catkins, con- 

 sisting of numerous short-stalked flowers; the perianth is deeply parted into 4 

 ovate blunt lobes; the stamens, 3 or 4, inserted at the base of the perianth under 

 the rudimentary ovary; filaments thread-hke, incurved in the bud, straight and 

 exserted where the flower opens; anthers 2-celled, borne on a very broad con- 

 nective, and opening lengthwise. The pistillate flowers are in shorter, stouter, 

 dense catkins; the perianth is sessile, irregularly deeply 4-lobed, the lobes ovate or 

 obovate, the two outer much the largest, accrescent, and enclosing the ovary; the 

 ovar}' is sessile, i-celled, terminated by a ver}^ short style divided into 2 thread- 

 like hairy stigmas; ovule soHtary, suspended from the top of the cell. The fruit 

 is a juicy syncarp, an aggregation of crowded more or less united and compressed 

 drupelets, consisting of the thickened juicy perianth enclosing the nutlets, which 

 are tipped with the remnants of the stigmas. 



Morus is the old classic name of the Mulberry tree, the type species being 

 Morus nigra Linnaeus. 



Our species are: 



Leaves glabrous beneath, or sparingly pubescent on the veins. 

 Leaves 6 to 20 cm. long, smoothish above; introduced Old World trees. 



Fruit white or pinkish. i. M. alba. 



Fruit black. 2. M. nigra. 



Leaves 2 to 6 cm. long, scabrous above; southwestern tree. 3. M. niicrophylla. 



Leaves softly pubescent beneath; fruit red or purplish; eastern tree. 4. M. rubra. 



I. WHITE MULBERRY Morus alba Linnsus 



This rapidly growing tree is of Asiatic origin and has come to us from Europe, 

 where it is very generally naturahzcd. With us it is frequently naturahzed from 

 New England southward, and attains a maximum height of 12 meters, with a 

 trunk diameter of i m. It was originally introduced as food for silkworms in an 

 early attempt to establish silk-culture in this country. 



The trunk is usually very short and low-branched; the bark is about 8 mm. 

 thick, broadly furrowed into Hght brown ridges. The twigs are round, slender, 

 hairy at first, becoming smooth, Hght grayish brown. The leaves are thin and 

 firm, ovate or ovate-oval, 6 to 15 cm. long, sharp or taper- pointed, rounded or 

 somewhat heart-shaped at the base, doubly toothed, sometimes lobed, slightly 

 hairy when unfolding, becoming smooth and Hght green above, paler and hairy 

 along the prominent venation beneath; the leaf-stalk is slender, somewhat hairy, 

 2 to 3 cm. long. The staminate catkins are slender, drooping, i to 2 cm. long, on 



