4:64 URTICACE^E. (NETTLE FAMILY.) 



5. HUMULTJS, L. HOP. 



Flowers dioecious ; the sterile in loose axillary panicles, with 5 sepals and 5 

 erect stamens. Fertile flowers in short axillary and solitary spikes or catkins ; 

 bracts foliaceous, imbricated, each 2-flowered, in fruit forming a sort of mem- 

 branaceous strobile. Calyx of a single sepal, embracing the ovary. Acheue 

 invested with the enlarged scale-like calyx. Embryo coiled in a flat spiral. 

 Twining rough perennials, with stems almost prickly downward, and mostly 

 opposite heart-shaped and palmately 3 - 7-lobed leaves, with persistent ovate 

 stipules between the petioles. (A late Latin name, of Teutonic origin.) 



1. H. LupulllS, L. (COMMON HOP.) Leaves mostly 3 - 5-lobed, com- 

 monly longer than the petioles ; bracts, etc., smoothish ; the fruiting calyx, 

 achene, etc., sprinkled with yellow resinous grains, which give the bitterness 

 and aroma to the hop. Alluvial banks, N. Eng. to western N. Y., the Great 

 Lakes and westward, and south in the mountains to Ga. July. (Eu., Asia.) 



6. MACLURA, Nutt. OSAGE ORANGE. Bois D'ARC. 



Flowers dioecious; the staminate in loose short racemes, with 4-parted calyx, 

 and 4 stamens inflexed in the bud ; the pistillate in a dense globose head, with 

 a 4-cleft calyx enclosing the ovary. Style filiform, long-exserted ; ovule pern 

 dulous. Fruit an achene, buried in the greatly enlarged fleshy calyx. Albu- 

 men none. Embryo recurved. Trees with milky juice, alternate entire 

 pinnately veined leaves, caducous stipules, axillary peduncles, and stout axil- 

 lary spines. (Named for the early American geologist, William Maclure.) 



1. M. aurantiaca, Nutt. A tree 30-50 high; leaves ovate to oblong- 

 lanceolate, pointed, mostly rounded at base, green and shining ; syncarp glo- 

 bose, yellowish green, 2-3' in diameter. E. Kan. and Mo. to N. Tex.; 

 extensively used for hedges. Wood bright orange. 



7. MORTIS, Tourn. MULBERRY. 



Flowers monoecious or dioecious ; the two kinds in separate axillary and 

 catkin-like spikes. Calyx 4-parted ; lobes ovate. Stamens 4 ; filaments elas- 

 tically expanding. Ovary 2-celled, one of the cells smaller and disappearing ; 

 styles 2, thread-form, stigmatic down the inside. Achene ovate, compressed, 

 covered by the succulent berry-like calyx, the whole spike thus becoming a 

 thickened oblong and juicy (edible) aggregate fruit. Trees with milky juice 

 and broad leaves ; sterile spikes rather slender. (The classical Latin name.) 



1. M. rubra, L. (RED MULBERRY.) Leaves heart-ovate, serrate, rough 

 above, down// beneath, pointed (on young shoots often lobed) ; flowers frequently 

 dioecious ; fruit dark purple, long. Rich woods, W. New Eng. to S. Ont., 

 the Dakotas, E. Kan., and southward. May. Large tree, ripening its black- 

 berry-like fruit in July. 



M. ALBA, L. (WHITE MULBERRY.) Leaves obliquely heart-ovate, acute, 

 serrate, sometimes lobed, smooth and shining ; fruit whitish. Spontaneous 

 near houses. (Adv. from Eu.) 



8. URTICA, Tourn. NETTLE. 



Flowers monoecious, or rarely dioecious, clustered, the clusters mostly in ra- 

 cemes, spikes, or loose heads. Ster. Fl. Sepals 4. Stamens 4, inserted around 



