976 



POLEMONIACEAE 



FAMILY 5. POLEMONIACEAE Vent. PHLOX FAMILY. 



Annual or usually perennial herbs or shrubby plants. Leaves alternate or 

 opposite, often crowded : blades entire or pinnately compound. Inflorescence 

 paniculate, corymbose, sometimes clustered. Flowers perfect, regular or nearly 

 so. Calyx of 5 partially united sepals. Corolla regular : limb five-lobed : lobes 

 convolute in aestivation. Androecium of 5 often unequal stamens adnate to 

 the corolla-tube. Anthers opening lengthwise and introrsely. Gynoecium of a 

 single carpel. Ovary 3-celled with a thick axis. Styles united. Stigmas 3. 

 Ovules solitary, erect, anatropous, or several in two series, ascending, amphitro- 

 pous. Fruit a 3-celled loculicidal capsule : valves usually separating from the 

 central axis to which the seeds are attached. Seeds solitary or several in each 

 cavity, with a spongy or mucilaginous testa. Endosperm fleshy or horny. 

 Embryo straight, axile. 



Calyx-tube distended and ruptured by the capsule at maturity. 



Corolla salverform : leaves opposite ; blades entire. 1. PHLOX. 



Corolla funnelform or rotate (in our species) : leaves often alternate ; blades 



commonly pinnatifid. 2. GILIA. 



Calyx-tube neither distended nor ruptured at maturity. 3. POLEMONIUM. 



1. PHLOX L. 



Annual or usually perennial, sometimes shrubby herbs, with erect or diffuse and creep- 

 ing stems. Leaves opposite, or sometimes alternate above : blades entire. Flowers in 

 terminal corymbose or panicled cymes. Calyx pedicelled : tube narrow, 5-ribbed : lobes 

 5, often tooth-like. Corolla white, blue, purple or red, salverform : tube slender : lobes 

 spreading, obovate to orbicular, or obcordate. Stamens 5, included. Filaments, unequally 

 adnate to the corolla-tube. Ovules 1-5 in each cavity. Capsule included in the calyx- 

 tube which it ruptures at maturity. Seeds sometimes narrowly winged, not emitting spiral 

 threads when wetted. 



Calyx-lobes fully as long as the tube or much longer. 

 Annual plants. 



Corolla-tube not surpassing the calyx, glabrous : ovules 4 or 5 in each cavity. 1. P. Roemeriana. 

 Corolla-tube surpassing the calyx, pubescent : ovule 1 in each cavity. 

 Leaves mostly alternate ; blades thin. 



Stems mostly less than 10 cm. long : leaf-blades narrowed at the base : 



corolla-lobes about 6 mm. long. 2. P. tennis. 



Stems mostly over to cm. long: leaf-blades broadest at the base: 



corolla-lobes about 10 mm. long. 3. P. Drummondii. 



Leaves mostly opposite ; blades thick. 



Stems villous-hirsute : leaf-blades bristly : capsules oblong. 4. P. vittosissima. 



Stems scabrous-pubescent : leaf-blades slightly pubescent : capsules 



subglobose. 5. P. aspera. 



Perennial plants. 



Plants with prostrate or creeping sterile shoots. 



Leaf-blades of thelsterile shoots of a spatulate^type, petioled. 6. P. reptans. 



Leaf-blades of the sterile shoots of an elliptic or oblong type, sessile. 7. P. divaricata. 



Plants without prostrate or creeping sterile shoots. 



linear-subulate, the tips not bristle-like. 



Calyx-lobes linear-subulate. 



Cymes compact, involucrate : capsules less than 4 mm. long. 



Upper leaves with blunt or merely acute blades. 8. P. amoena. 



Upper leaves with somewhat acuminate blades. 9. P. Lighthipei. 



Cymes open, not involucrate : capsules fully 5 mm. long. 10. P. Floridana* 



Calyx-lobes- with bristle-like tips. 



Calyx copiously pubescent : branches of ithe inflorescence closely pubes- 

 cent. 11. P. pilosn. 

 Calyx glabrous or nearly so : branches of the inflorescence glabrous or 



with few scattered hairs. 12. P. detonsa. 



Calyx-lobes shorter than the tube, sometimes apparently.longer by the splitting of 



the sinuses. 

 Stems prostrate, spreading, forming large mats. 



Leaves little if at all clustered : corolla-lobes cleft to the middle or below it. 13. P. biflda. 

 Leaves conspicuously or densely clustered : corolla-lobes entire or notched. 

 Calyx 4-6 mm. long : plants forming dense mats. 



Upper part of plant glandular : corolla-lobes deeply notched. 

 Upper part of plant not glandular : corolla-lobes shallowly notched. 

 Calyx 8-10 mm. long : plants not in dense mats. 

 Stems erect or ascending, not forming mats. 



A. Calyx-lobes lanceolate, subulate-lanceolate or nearly triangular, 

 a. Calyx-lobes % or % as long as the tube. 



Upper leaf-blades with broadly rounded or cordate bases ; lower leaves 



with petioled blades. 



Upper leaf-blades obtuse or acute at the base ; lower leaves with sessile 

 blades. 



14. P. Brittmii. 



15. P. subulata. 



16. P. Hentzii. 



17. P. ovata. 



18. P. glaberrima^ 



