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



beautiful flowers. Species of the genera Phlox, Gilia, and Polemonium 

 and the climbing Cobaea scandens are garden favorites. 



Key to the genera 



1. Calyx in fruit not becoming ruptured by the capsule; corolla regular; leaves 

 alternate, not prickly (2) . 

 2. Leaves simple; calyx tube scarious and whitish between the ribs, with a 

 short toothlike fold in each sinus 2. Collomia. 



2. Leaves pinnately compound with numerous leaflets; calyx entirely herba- 



ceous and green, the tube not distended or folded between the ribs. 



4. Polemonium. 

 1. Calyx in fruit becoming ruptured by the capsule or, if not so (in Gilia, sub- 

 genus Navarretia), then the plant annual, the leaves prickly, the inflores- 

 cence involucrate, and the sepals unequal (3) . 



3. Corolla regular, salverform or, if somewhat funnelform, then the plant 



suffrutescent, the stems tall and weak, and the corolla whitish, 1.5 to 

 2 cm. long; stamens included, inserted at different levels in the corolla 



tube ; leaves entire, narrow, mostly opposite 1. Phlox. 



3. Corolla regular or irregular, funnelform, campanulate, nearly rotate or, 

 if salverform, then the stamens all inserted at the same level; stamens 

 often exserted (4). 

 4. Bracts (when present) and the calyx only partly scarious; corolla regular 

 or only slightly bilabiate; stamens included or moderately exserted, 

 the filaments erect or slightly declined; leaves usually lobed or dis- 

 sected 3. Gilia. 



4. Bracts and calyx wholly scarious except the midrib; corolla usually dis- 

 tinctly bilabiate; stamens long-exserted, the filaments strongly 

 declined and incurved; leaves entire, or merely serrate or dentate. 



5. Loeselia. 

 1. PHLOX 



Contributed by Edgar T. Wherry 



Perennial herbs or the plants somewhat woody; leaves opposite, 

 entire; inflorescence cymose, often reduced to a solitary flower; corolla 

 salverform or rarely funnelform; stamens 5, irregular; ovules 1 to 3 

 in each carpel. 



Flowering occurs twice a year, in spring and occasionally again after 

 summer rains. The species are in many cases not well defined. Some 

 have been renamed more than once, and names are often applied to 

 specimens not closely related to the type material on which those 

 names were originally founded. 



The phloxes are popular garden plants, especially where a mass of 

 blooms is desired. Several of the native species of Arizona have been 

 brought under cultivation. Phlox tenuifolia grows naturally in the 

 chaparral and may do well under cultivation in desert regions. The 

 flowers of phlox are relished by sheep. 



Key to the species 



1. Shoots tending to be short and branched, and the inflorescence to be simple: 

 Depressed phloxes (2) . 

 2. Pubescence more or less glandular (3). 



3. Glandular pubescence extending throughout the herbage and even on to 

 the corolla tube 1. P. gladiformis. 



3. Glandular pubescence limited to the inflorescence-herbage; corolla tube 



glabrous 2. P. caespitosa. 



2. Pubescence wholly eglandular (4). 



4. Leaves thickish, gray green, more or less acerose (5) . 



5. Leaf outline linear-subulate; pubescence sparse; calyx intercostally 



carinate 3. P. austromontana. 



5. Leaf outline ovate; pubescence copious; calyx intercostally flat. 



4. P. covillei. 



