120 Iloustonia ccerulea. 



Root perennial, sending up numerous, slender, twisted, obscure- 

 ly square green stems, about four or six inches high, forked above. 

 Radical leaves numerous, spathulated, ciliated, and slightly pubes- 

 cent; those of the stem opposite, fewer, ovate, ending in a broad 

 petiole, and becoming narrower as they approach the top of the 

 stem, until they are sometimes linear obtuse, and glabrous. Calix 

 obtusely quadrangular, four-toothed, an eighth of an inch long, acute. 

 Germ purplish. Flower-buds yellow, and nodding before the flower 

 expands. Tube of the corolla externally pale, and internally dark- 

 yellow. Segments of the limb four, ovate, terminating in an abrupt 

 point, curved backwards, flax-flower-blue, sometimes white, with the 

 centre white, variegated on each segment by two spots of bright 

 yellow. Stamens included, pistil just perceptible above the throat 

 of the corolla, sometimes white. Grows in grassy places on way 

 sides, the grassy borders of fields, edges of woods, from the northern- 

 most to the most southern extremity of the Union. Flowering from 

 April till September. It prefers rich soils, and in such is more ro- 

 bust than in sandy and shady places, where it becomes tall and more 

 slender, with smaller leaves and flowers. 



The genus to which this pretty little plant belongs, was named by 

 Gronovius and Linnseus after Dr. William Houston, who died in 

 1733. He was a botanist of eminence who resided many years in 

 the West Indies, and visited South America between the years 1728 

 and 1732. He rendered essential services to the science he culti- 



