FLOWERING PLAXTS AND FERNS OF ARIZONA 639 



Key to the species 



1. A shrub, up to 2.5 m. high; leaves mostly simply pinnate, with o to 9 leaflets, 

 these crenulate or crenate with obtuse or acutish, often glandular-mucron- 

 ulate teeth, light or yellowish green, commonly rather thick, persistently 

 and usually copiously puberulent beneath, lance-ovate or oblong-ovate; 

 peduncles and pedicels sparsely puberulent or glabrate__ 1. A. humilis. 



1. A large herb, 1 to 2 m. high; leaves (all except the uppermost) ternate or 

 biternate, the ultimate divisions pinnate with 3 to 5 leaflets, these doubly 

 crenate-serrate with setose-cuspidate teeth, deep green, very thin, puber- 

 ulent only on the veins beneath when mature, lance-ovate to broadly 

 ovate; peduncles and pedicels copiously puberulent 2. A. racemosa. 



1. Aralia humilis Cav., Icon. PL 4: 7. 1797. 



Cochise, Santa Cruz, and Pima Counties, 3,500 to 5,000 feet, 

 canyons, August and September. Southern Arizona and Mexico. 



The stems reach a height of 3 m. (10 feet) and a diameter at base of 

 5 cm., and the older bark is rough. 



2. Aralia racemosa L., Sp. PL 273. 1753. 



Aralia bicrenata Woot. and Standi., Contrib. U. S. Natl. 



Herbarium 16: 157. 1913. 

 Aralia arizonica Eastw., Calif. Acad. Sci. Proc. ser. 4, 20: 148. 



1931. 



Apache and Coconino Counties to Cochise County, 7,300 to 9,500 

 feet, rich soil of coniferous forests, preferring shade, July and August, 

 type of A. arizonica from the Chiricahua Mountains (Kusche in 1929). 

 Canada to Georgia, Arizona, and northern Mexico. 



American spikenard. The plants reach a height of 2 m. (7 feet). 

 The form occurring in Arizona (A. bicrenata Woot. and Standi.) 

 should perhaps be regarded as a variety, having more deeply serrate 

 margins of the leaflets and a more ample inflorescence than in most 

 specimens from the eastern United States. The fruits are eaten by 

 various birds. 



91. UMBELUFERAE. Parsley family 



Contributed by Mildred E. Mathias and Lincoln Constance 



Plants herbaceous, annual or perennial, with commonly hollow 

 stems; leaves alternate or basal, usually compound, with usually 

 sheathing petioles; flowers small, regular, in simple or compound 

 umbels, or the umbels sometimes proliferous or capitate; rays some- 

 times subtended by bracts forming an involucre; umbellets usually 

 subtended by bracelets forming an involucel; calyx tube wholly adnate 

 to the ovary, the calyx teeth obsolete or small; petals 5, usually with 

 an inflexed tip; stamens 5, inserted on an epigynous disk; ovary in- 

 ferior, 2-celled, with 1 anatropous ovule in each cell; styles 2, some- 

 times swollen at base to form a stylopodium; fruit consisting of 2 

 mericarps united by their faces (commissure), each mericarp with 5 

 ribs, 1 down the back (dorsal rib), 2 on the edges near the commissure 

 (lateral ribs), and 2 between the dorsal and lateral ribs (intermediate 

 ribs), with oil tubes usually present in the intervals (spaces between 

 the ribs), and on the commissural surface: mericarps 1-seeded, splitting 

 apart at maturity, usually suspended from the summit of a slender 

 prolongation of the axis (carpophore) ; embryo small, the endosperm 

 cartilaginous. 



286744°— 42 11 



