782 MISC. PUBLICATION 4 2 3, U. S. DEPT. OF AGRICULTURE 



Key to the species 



1. Calyx teeth connivent at maturity, closing the tube, the whole calyx thus 



tapering from the middle of the tube to the apex 4. H. deummondii. 



1. Calyx teeth usually spreading, the upper ones more or less reflexed, the calyx 

 thus clearly bilabiate (2") . 

 2. Tube of the calyx notably distended at base at maturity, the pouch forming 

 more than half of the length of the tube, the latter about one-third as 



wide as long 2. H. nanum. 



2. Tube of the calyx only slightly distended, about one-fourth as wide as long (3) . 

 3. Leaves clearly and sharply dentate, at least in the upper half (4). 



4. Leaves serrate, with several or numerous teeth, the veins apparent; 

 corolla tube retrorsely hairy within; early leaves villous. 



5. H. DENTATUM. 



4. Leaves inconspicuously dentate, with 4 to 6 teeth, or entire, the veins 



inconspicuous; corolla tube glabrous within; early leaves glabrous. 



6. H. OBLONGIFOLIUM. 



3. Leaves entire or essentially so (5). 



5. Leaves linear-lanceolate, pointed, strict, stiffish, the lateral veins 



straight, rather prominent, parallel 1. H. hyssopifolium. 



5. Leaves elliptic-lanceolate, oblong, or oval, usually spreading, the lateral 

 veins not markedly straight and parallel (6). 

 6. Stems prostrate, wiry, 5 to 20 cm. long; corolla tube hirtellous within 



and somewhat annulate near the middle 3. H. diffusum. 



6. Stems erect, 25 to 50 cm. long, stiffish; corolla tube glabrous within or 

 essentially so 6. H. oblongifolium. 



1. Hedeoma hyssopifolium A. Gray, Amer. Acad. Arts and Sci. Proc. 



11: 96. 1876. 

 Southern Apache and Coconino Comities to Cochise, Santa Cruz, 

 and Pima Counties, 5,000 to 8,000 feet, slopes and canyons, May to 

 October, type from Mount Graham (Rothrock 418). New Mexico, 

 Arizona, and northern Mexico. 



2. Hedeoma nanum (Torr.) Greene, Pittonia 3: 339. 1898. 



Hedeoma dentata var. nana Torr., U. S. and Mex. Bound. 



Bot, 130. 1859. 

 Hedeoma thymoides A. Gray, Syn. Fl. 2 *: 362. 1C78. Not of 



Persoon. 



Key to the subspecies 



1. Calyx tube 3.5 to 4 mm. long; corolla tube 5 to 7 mm. long; basal leaves present, 



purple beneath, more than 1 cm. long subsp. macrocalyx. 



I. Calyx tube 2.5 to 3 (rarely 4) mm. long; basal leaves usually deciduous (2). 

 2. Stems forming a close bunch or tuft, 10 to 15 cm. high, sparingly covered 

 with retrorse pubescence above, glabrous below; leaves about 5 mm. long. 



Subsp. CALIFORNICUM. 



2. Stems loose, 10 to 35 cm. high, with downward-curling pubescence; leaves 

 usually 5 to 10 mm. long subsp. typicum. 



Subsp. macrocalyx Stewart occurs in Yavapai, Gila, Maricopa, 

 Pinal, and Pima Counties. Subsp. calijornicum Stewart is known in 

 Arizona only from Toroweap Valley (northern Mohave County). 

 Subsp. typicum Stewart ranges from Coconino and Mohave Counties 

 to Cochise, Pima, and Yuma Counties. The species as a whole ranges 

 from western Texas to southeastern California and northeastern 

 Mexico. 



3. Hedeoma diffusum Greene, Pittonia 3: 338. 1898. 



Hedeoma blepharodonta Greene, ibid. p. 339. 



Navajo, Coconino, and Yavapai Counties, commonly 6,000 to 7,000 

 feet, May to July, type from Flagstaff (Rusby in 1883). Known only 

 from northern Arizona. 



