FLOWERING PLANTS AND FERNS OF ARIZONA 167 



2. Spikelets few in loose umbels with unequal rays, or solitary (3). 



3. Umbels mostly simple; spikelets commonly more than 5 mm. long; achenes 



fully 1 mm. long, the ribs noticeably tuberculate_ 3. F. baldwiniana. 

 3. Umbels compound; spikelets less than or barely 5 mm. long; achenes less 



than to barely 1 mm. long, not or obscurely tuberculate. 



4. F. ALAMOSANA. 



1. Fimbristylis thermalis S. Wats, in King, Geol. Expl. 40th Par. 5: 



360. 1871. 

 Grand Canyon, Coconino County, foot of Bright Angel Trail 

 (Tourney, Wooton, Leiberg). Nevada, northern Arizona, and Cali- 

 fornia. 



2. Fimbristylis vahlii (Lam.) Link, Hort, Berol. 1: 287. 1827. 



Scirpus vahlii Lam., Tabl. Encycl. 1: 139. 1791. 



Yuma, in sand along the Colorado River, "very abundant, forming 

 small dense cushions" (Thornber in 1912). North Carolina to Florida, 

 westward to California. 



3. Fimbristylis baldwiniana (Schult.) Torr., Ann. Lye. N. Y. 3: 344. 



1836. 



Scirpus balduinianus Schult., Mant. 2: 85. 1824. 



Bowie, Cochise County (Jones 4317), Sycamore Canyon near 

 Ruby, Santa Cruz County (Kearney and Peebles 14476), September. 

 Pennsylvania to Florida, west to Kansas and southeastern Arizona. 



4. Fimbristylis alamosana Fernald, Amer. Acad. Arts and Sci. Proc. 



36: 491. 1901. 

 Sycamore Canyon near Ruby, Santa Cruz County (Goodding 6633, 

 Kearney and Peebles 14475), in moist sand, August to September. 

 Southern Arizona and Sonora. 



6. BULBOSTYLIS 



Plants annual or perennial; stems and leaves filiform; spikelets 

 terete, in small umbels or heads, or solitary; scales spirally imbricate; 

 achenes triangular, more or less distinctly rugose transversely, the 

 apical tubercle persistent. 



Key to the species 



1. Stems up to 40 cm. long, becoming hardened and bulblike at base; spikelets in 

 a small cluster, or sometimes solitary, at the apex of the culm, none strictly 

 basal; achenes 1 to 1.2 mm. long 1. B. juxcoides. 



1. Stems not more than 8 cm. long, not becoming bulblike at base; spikelets 

 both at the apex of the culm and at the base of the plant among the Leaves, 

 usually solitary; achenes less than 1 mm. long 2. B. punckii. 



1. Bulbostylis juncoides (Yahl) Kukenthal ex Osten., An. Mus. Hist. 

 Nat. Montevideo ser. 2, 3: 185. 1932. 



Schoenus juncoides Vahl, Enum. PL 2: 211. 1806. 



In moist sand, Yavapai, Cochise, Santa Cruz, and Pima Counties. 

 3,000 to 6,000 feet. Western Texas to Arizona and Mexico; South 

 America. 



The Arizona form is var. ampliceps Kukenthal, with more expanded 

 inflorescence than in the typical form. Small apparently annual 

 specimens, from the northern limits of the range, with stems not 

 hardened and bulblike at base, simulate B. capUlaris (L.) C. B. Clarke 



