1498 COXTKIBUTIONS FROM THE K^ATIONAI, EEKBARIUM 



6. Aster spinosus Benth. PI. Hartw. 20. 1839. 

 Leucot>yris spinosn Greene, Pittonia 3: 244. 1897. 



Aster spi7iosus spinossisirtnis T. S. Brandeg. Univ. Calif. Publ. Bot. 6: 375. 

 1917. 



Baja California and northern Mexico to Oaxaca; type from Aguascalientes. 

 Texas to Arizona and California; Guatemala, Costa Rica. 



Woody below, up to 2.5 meters high, much branched; stem and branches 

 striate-angled, usually bearing stout, subterete or flattened, axillary or supra- 

 axillary spines up to 5 cm. long; leaves subulate t-o linear, 4 cm. long or usually 

 much less, deciduous; heads 1 to 1.5 cm. wide, sohtary at tips of branchlets; 

 involucre 3 to 5 mm. high, of lanceolate narrowly thin-margined phyllaries; 

 rays white; achenes glabrous. 



7. Aster frutescens S. Wats. Proc. Amer. Acad. 24: 55. 1889. 



Central western Baja California and adjacent islands; type from Los Angeles 

 Bay. 



Shrub about 90 cm. high, white-barked; young parts hirtellous-glandular; 

 leaves sessile. 1.5 to 2.5 cm. long, 5 to 12 mm. wide, repandly spiny-toothed, 

 sessile; heads 1.5 to 2 cm. wide, solitary at tips of branchlets; involucre 7 to 10 

 mm. high, graduate, of lanceolate glandular phyllaries with attenuate greenish 

 tips; rays lilac. 



8. Aster leucelene Blake in Tidestrom, Contr. U. S. Nat. Herb. 25: 562. 1925. 

 Inula ericoidesToTT. Ann. Lye. N. Y. 2: 212. 1828. Not Aster ericoidesL. 1753. 

 Aster ericaefoJius Rothr. Bot. Gaz. 2: 70. 1877. Not A. ericaefolius Forsk. 



1775. 



Aster ericaefolius tenuis A. Gray, Syn. Fl. 1^: 198. 1884. 



Leucelene ericoides Greene, Pittonia 3: 148. 1896. 



Chihuahua to San Luis Potosi. Kansas to Texas and Utah; type collected 

 "on the Canadian"? 



Slender, many-stemmed, suffruticulose, the stein strigose; lowest leaves usually 

 spatulate, strigose and often hirtellous-ciliate, the upper subulate to linear, 2 to 

 10 mm. long; heads about 1.5 cm. wide; involucre 5 to 7 mm. high, graduate, 

 the appressed, linear or linear-lanceolate phyllaries acute, scarious-margined, 

 strigose to subglabrous; rays white, often turning purplish red. 



28. ERIGEBON L. Sp. PI. 863. 1753. 



Characters of Aster, but involucre obscurely or not at all graduate, rays usually 

 more numerous and narrow, and style branches with short obtuse tips. 



The English names '"fleabane" and "daisy" are frequently applied to the 

 species of this genus occurring in the LTnited States. 



Rays 1 to 1.5 mm. long; involucre 2 to 3 mm. high 1. E. socorrensis. 



Rays 3 to 6 mm. long; involucre 3 to 5 mm. high. 



Involucre finely glandular-puberulous, otherwise essentially glabrous. 



2. E. exilis. 

 Involucre sparsely or densely strigose or hirsute, sometimes also glandular- 

 puberulous. 

 Stem and peduncles pubescent with spreading or refiexed hairs. 



3. E. calcicola. 

 Stem and peduncles strigose or pubescent with ascending hairs. 



Involucre more or less densely glandular-puberulous as well as hirsute. 



4. E. ervendbergii. 

 Involucre sparsely or densel}' strigose or strigillose, not glandular- 

 puberulous 5. E. karvinskianus. 



