FLOWERING PLAXTS AND FERXS OF ARIZONA 77 



Key to the species 



1. Achenes with a conspicuous, horizontal, straight or slightly curved beak, not 

 winged or crested on the faces, the marginal wing broad, especially at top; 

 terminal leaf lobe commonly equaling or longer than the basal lobes. 



1. S. LATIFOLIA. 



1. Achenes minutely or inconspicuously beaked (2). 



2. Basal leaf lobes not longer, usually shorter, than the terminal lobe; achenes 

 with an erect or nearly erect beak, not winged or crested on the faces, the 

 marginal wing broad and rather thick; terminal leaf lobe commonly 

 ovate or broadly lanceolate, acute or slightly acuminate. 



2. S. CUXEATA. 

 2. Basal leaf lobes much longer than the terminal lobe; achenes with a minute 

 horizontal or ascending beak (3). 

 3. Leaf blades not more than 25 cm. long, the terminal lobe linear or lanceo- 

 late, usually long-acuminate, commonly less than half as long as the 

 basal lobes; scape usually simple; bracts 6 to 8 mm. long; achenes 



without facial wings 3. S. loxgiloba. 



3. Leaf blades 20 to 40 cm. long, the terminal lobe ovate to broadly lanceo- 

 late, acute or short-acuminate, more than half as long as the basal 

 lobes; scape sometimes branched; bracts 10 to 30 mm. long; achenes 

 with facial wings 4. S. greggii. 



1. Sagittaria latifolia Willd., Sp. PL 4: 409. 1806. 



Near Tucson, Pima County (Thornber 250), 2,400 feet. Throughout 

 most of North America. 



2. Sagittaria cuneata Sheld., Torrey Bot. Club Bui. 20: 283. 1893. 



Sagittaria arifolia Nutt. ex J. G. Smith, Sagit. and Lophot. 6 

 1894. 

 Sacaton, Pinal County (Harrison and Peebles 1999), 1,270 feet. 

 Ontario to British Columbia, south to Michigan, New Mexico, 

 southern Arizona, and California. 



3. Sagittaria longiloba Engelm. in Torr., U. S. and Mex. Bound. Bot. 



212. 1859. 



Bonita, Graham County (Shreve 5217), 5,200 feet. Kansas to 

 Colorado, Arizona, and Mexico. 



4. Sagittaria greggii J. G. Smith, Sagit. and Lophot. 17. 1894. 

 Forty miles southwest of Tucson, Pima County (Harrison 8937), 



about 3,000 feet. Arizona, California, and Mexico. 



This form apparently intergrades with S. longiloba, but the material 

 available is too scanty to permit a decision as to the validity of the 

 species. 



7A. HYDROCHARITACEAE. Frogs-bit family 



After this work went to pr^ss, there came to the attention of the 

 authors an unidentified species of Anacharis, collected in water near 

 Williams, Coconino County (M. Wetherill in 1938). This adds 

 another family to the known flora of Arizona, distinguished) from all 

 other aquatic monocotyledons of this State by the inferior ovary. In 

 the genus Anacharis the stems are submersed and very leafy, with 

 thin, opposite or whorled, 1-nerved leaves. The small, mostly uni- 

 sexual flowers are solitary in the axils and are subtended by a tubular, 

 sessile spathe. The perianth of the pistillate flowers consists of a 

 remarkably long, slender tube and a small 6-parted limb. 



