FLOWERING PLANTS AND FERNS OF ARIZONA 229 



Key to the genera 



1. Plant a small tree; pistillate and staminate flowers both in catkins: perianths 

 of the pistillate flowers becoming thick, succulent, and fused, the inflores- 

 cence as a whole becoming a juicy oblong aggregate fruit 1. Morus. 



1. Plant climbing, perennial, herbaceous or suffrutescent ; staminate flowers in 

 loose panicles, the pistillate flowers in short catkinlike spikes; bracts of the 

 pistillate inflorescence foliaceous, imbricate, becoming much enlarged 

 and membranous in fruit _ 2. Humulus. 



1. MORUS. Mulberry 



A tree or large shrub; leaves alternate, crenate-serrate or palmately 

 lobed (especially on young shoots); perianth 4-parted; stigmas 2, 

 linear, spreading. 



1. Morus microphylla BuckL, Acad. Nat. Sci. Phila. Proc. 1862: 8. 

 1863. 



Greenlee County to Yavapai County, south to Cochise, Santa Cruz, 

 and Pima Counties, 3,500 to 5,200 feet, usually along streams. 

 Western Texas to Arizona and northern Mexico. 



Texas mulberry. The stems seldom exceed 4.5 m. (15 feet) in 

 height. The tart, palatable fruits are gathered by the Papago 

 Indians and are greedily eaten by birds and other animals. It is 

 reported that the Havasupai Indians in the Grand Canyon cultivate 

 the native mulberry. There is great variation in the shape of the 

 leaves, and, largely on this basis, several segregate species founded on 

 Arizona types were described by E. L. Greene. These are: M. con fin is 

 (type Pringle in 1881, Santa Catalina Mountains); M. crataegifolia 

 (type Hough in 1905, Blue River, Graham County); M. radulina 

 (type Fernow in 1896, Beaver Creek, Yavapai County) ; and M. grisea 

 (type Palmer in 1869, Hell Canyon, Yavapai County). The last is an 

 exceptionally pubescent form. 



2. HUMULUS. Hop 



Plant twining, perennial, herbaceous or nearly so; leaves opposite 

 palmately 3- to 7-lobed; perianth 5-parted in the staminate flowers, 

 entire in the pistillate flowers; stigmas 2, filiform. 



1. Humulus americanus Nutt., Acad. Nat. Sci. Phila. Jour. ser. 2, 1: 

 181. 1847. 



Humulus lupulus L. var. neomexicanus A. Nels. and Cockerell, 

 Biol. Soc. Wash. Proc. 16: 45. 1903. 



Apache, Navajo, and Coconino Counties, south to Graham and 

 Pima Counties, 5,500 to 9,500 feet, mountain woods. Rocky Moun- 

 tain region, south to New Mexico and Arizona. 



The pistillate inflorescences of the closely related European species 

 (H. lupulus) are used in the brewing of malt beverages to impart the 

 bitter flavor, and in medicine as a tonic and soporific. The south- 

 western form apparently was utilized by the Indians, the Apache 

 name being stated to mean to "make bread with it." Rare cases of 

 dermatitis from contact with the plant have been reported. 



28. URTICACEAE. Nettle family 



Plants herbaceous; leaves simple, opposite or alternate, with or 

 without stipules; inflorescences axillary; flowers perfect or unisexual; 



