444 URTICACE^E. (NETTLE FAMILY.; 



4 . MORUS, Tourn. Mulberry. 



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

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

 ly expanding. Ovary 2-celled, one of the cells smaller and disappearing : styles 2, 

 thread-form, stigmatic down the inside. Achenium ovate, compressed, covered 

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

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

 rounded leaves : sterile spikes rather slender. (Mope'a, the ancient name.) 



1. M. rubra, L. (Red Mulberry.) Leaves heart-ovate, serrate, rough 

 above, downy underneath, pointed (on young shoots often lobed) ; flowers frequently 

 dioecious ; fruit dark purple, long. — Rich woods, NeAV England to Illinois and 

 southward. May. — Small tree, ripening its blackberry-like fruit in July. 



2. M. Alba, L. (White Mulberry.) Leaves obliquely heart-ovate, 

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

 near houses : introduced for feeding silk- worms. (Adv. from Eu.) 



5. TJ It TIC A, Tourn. Nettle. 



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

 cemes, spikes, or loose heads. Sler. FL Sepals 4. Stamens 4, inserted around 

 the cup-shaped rudiment of a pistil. Fert. FL Sepals 4, in pairs ; the 2 outer 

 smaller and spreading ; the 2 inner flat or concave, in fruit membranaceous and 

 enclosing the straight and erect ovate flattened achenium. Stigma sessile, cap- 

 itate and pencil-tufted. — Herbs armed with stinging hairs. Leaves opposite : 

 stipules in our species distinct. Flowers greenish ; in summer. (The classical 

 Latin name; from uro, to burn.) 



* Perennials : flower-clusters in branching panicled spikes, often dioecious. 



1. U. gracilis, Ait. Sparingly bristly, slender (2° -6° high); leaves ovate- 

 lanceolate, pointed, serrate, 3 - 5-nerved from the rounded or scarcely heart-shaped 

 base, almost glabrous, the elongated slender petioles sparingly bristlu ; spikes slender 

 and loosely panicled. (XL prbcera, Willd.) — Fence-rows and moist ground: 

 common. Stings few. 



2. U. dioica, L. Very bristly and stinging (2° - 3° high) ; leaves ovate, heart- 

 shaped, pointed, very deeply serrate, downy underneath as well as the upper part of 

 the stem ; spikes much branched. — Waste places and roadsides, chiefly eastward. 

 (Nat. from Eu.) 



* * Annuals: flower-clusters chiefly axillary and shorter than the petiole, androgynous. 



3. U. urens, L. Leaves elliptical or ovate, very coarsely and deeply serrate 

 with long spreading teeth, the terminal not longer than the lateral ones ; flower- 

 clusters 2 in each axil, small and loose. — Waste grounds, near dwellings, east- 

 ward : scarce. Plant 8'- 12' high, with sparse stings. (Nat. from Eu.) 



4. IT. Chamsedryoides, Pursh. Leaves ovate and mostly heart-shaped, the 

 upper ovate-lanceolate, coarsely serrate-toothed ; flower-clusters globular, 1 - 2 in 

 each axil, and spiked at the summit. (XJ. gracilis & U. verna, Raf XT. purpu- 

 rascens, Nutt.) — Alluvial shaded soil, Kentucky and southward. — Slendej. 

 6' - 30' high, sparsely beset with stings. 



