GENUS I. 



MADDER FAMILY. 



251 



or less concave, not angled. Seed-coat reticulate or roughened ; endosperm horny ; embryo 

 club-shaped. [Named in honor of Dr. William Houston, botanist and collector in South 

 America, died 1733.] 



About 25 species, natives of North America and Mexico. Type species : Houstonia coerulea L. 

 * Plants i '-7' high; peduncles i -flowered. 



t Peduncles filiform, i'-2j^' long. 



Erect; leaves obovate or spatulate, narrowed into petioles. i. H. coerulea. 



Diffuse or spreading; leaves nearly orbicular. 2. H. serpyllifolia. 



tt Peduncles 3"-i8" long, stouter. 



Calyx-lobes narrow, about equalling the capsule. 3. H. patens. 



Calyx-lobes broad, much exceeding the capsule. 4. H. minima. 



** Plants 4'-i8' high; flowers cymose. 



Calyx-lobes lanceolate-subulate, 2 to 3 times as long as the capsule. 5. H. lanceolata. 



Calyx-lobes linear-subulate, scarcely longer than the capsule. 



Leaves broad, ovate, or ovate-lanceolate. 6. H. purpurea. 



Leaves oblong or spatulate, ciliate. 7. H. ciliolata. 



Leaves linear-lanceolate or oblanceolate, not ciliate. 8. H. longifolia. 



Leaves filiform or narrowly linear. 



Flowers loosely cymose on filiform pedicels ; leaves not fascicled. 

 Flowers densely cymose on very short pedicels ; leaves usually fascicled. 



9. H. tenuifolia. 

 10. H. angustifolia. 



i. Houstonia coerulea L. Bluets. 



Innocence. Eyebright. Fig. 3912. 

 Houstonia coerulea L. Sp. PI. 105. 1753. 

 Hedyotis coerulea Hook. Fl. Bor. Am. i : 286. 



1833. 

 Oldenlandia coerulea A. Gray, Man. Ed. 2, 



174. 1856. 



Erect, 3'-7' high, glabrous, or nearly so, 

 perennial by slender rootstocks and form- 

 ing dense tufts. Lower and basal leaves 

 spatulate or oblanceolate, about 6" long, 

 sometimes hirsute or ciliate, narrowed into 

 a petiole, the upper oblong, sessile ; flowers 

 solitary on filiform terminal and axillary 

 peduncles ; corolla salverform, violet, blue, 

 or white with a yellow center, 4" -6" broad, 

 its tube slender and about the length of the 

 lobes or longer ; capsule didymous, com- 

 pressed, about 2" broad and broader than 

 long, the upper half free from the calyx 

 and shorter than its lobes. 



In open grassy places, or on wet rocks, 

 Miquelon and Nova Scotia to Quebec, New 

 York, Michigan, Georgia, Alabama, Tennessee 

 and Missouri. April-July, or producing a few 

 flowers through the summer. Includes several 

 races. Called also quaker-ladies, quaker- 



i rjrfyb. i^ 



bonnets, Venus'-pride. Bright eyes. Angel- 

 eyes. Blue-eyed-grass or -babies. Wild forget- 

 me-not. Nuns. Star-of-Bethlehem. Little 

 washerwoman. 



2. Houstonia serpyllifolia Michx. 



Thyme-leaved Bluets. 



Fig. 39I3- 



Houstonia serpyllifolia Michx. Fl. Bor. Am. 



i: 85. 1803. 



Hedyotis serpyllifolia T. & G. Fl. N. A. 2 : 39. 

 ' 1841. 



Perennial ; stems prostrate or diffuse, 

 slender, glabrous, 4'-io' long. Leaves or- 

 bicular or broadly oval, abruptly petioled, 

 3"-4" long, sometimes hispidulous ; or those 

 of the flowering stems narrower, distant; 

 flowers on terminal and axillary filiform 

 peduncles ; corolla usually deep blue, 4"-6" 

 broad, its tube rather shorter than the 

 lobes ; capsule similar to that of the pre- 

 ceding species but usually slightly larger, 

 nearly as long as the calyx. 



Somerset County, Pennsylvania, to the high 

 mountains of Virginia and West Virginia, 

 South Carolina, Georgia and east Tennessee. 

 May. 



