!907] Hall Compositae of Southern California. 263 



at apex, crowned with an entire or denticulate border, 10 to 15- 

 ribbed, terete or 4 or 5 of the ribs stronger than the others ren- 

 dering the achene somewhat 4 or 5-angled. Pappus-bristles soft, 

 scabrous, more or less united at base and falling away together, 

 or with 1 to 8 stronger ones which are more persistent. 



Involucre imbricated in several series, all but the innermost bracts (which 

 vary from oval to linear) orbicular or ovate and very obtuse, all 



silvery-scarious with a dark medial line 1. M. Coulteri. 



Involucre much less imbricated, its bracts lanceolate to linear, all acute. 

 Annuals, less than 6 dm. high. 



Scapose: leaves all basal: peduncles monocephalous 



2. M. Calif ornica. 



Caulescent: stems branching and bearing leaves, at least below. 

 Leaves and their lobes filiform, elongated: persistent pappus- 

 bristles 2 or more 3. M. glabrata. 



Leaves and their lobes broader and shorter: persistent bristles 

 only one or lacking. 



Ligules about 1 cm. long: desert species 4. M. sonchoides. 



Ligules 2 mm. long: stems leafy only below: montane species. 

 Flowers yellow: one pappus-bristle and a crown of setulose 



teeth persistent 5. M. Clevelandi. 



Flowers pale: pappus all deciduous 6. M. obtusa. 



Ligules short: stems very leafy throughout. 



Involucres 10 to 12 mm. high : leaves and their lobes acute 



7. M. foliosa. 



Involucres 6 or 7 mm. high: lower leaves with obtuse lobes 

 8. M. indecora. 



Perennials, mostly with suffrutescent base (the herbaceous species with 



stems 1 m. or more high). 

 Herbage white-tomentose when young: inner bracts of the involucre 



obtuse 9. M. incana. 



Herbage essentially glabrous: involucral bracts attenuate. 



Stems several, much branched from the base 10. M. saxatilis. 



Stem solitary, usually simple below 11. M. altissima. 



1. M. Coulteri Gray, PL Fendl. 113 (1849). Malacolepis 

 Coulteri Heller, Muhlenbergia ii. 147 (1906). SNAKE'S HEAD. 



Annual, 1 to 6 dm. high : stem simple from the base, panic- 

 ulately branched above: herbage glabrous and glaucescent: cau- 

 line leaves sinuately pinnatifid, broad or somewhat auriculate at 

 the sessile base and with an elongated terminal lobe : heads sub- 

 globose : involucre 12 to 15 or 18 mm. high ; its bracts silvery- 

 scarious with a linear central portion green, regularly imbricated 

 in several ranks, the short outer ones orbicular, the inner ones 



