80 Rhodora [Aran 



tion are natives of Texas, where S. vernalw was originally collected, 

 and if they inter-cross readily there is no reason to doubt the proba- 

 bility of the type of S. vernalis having been of hybrid origin. In 

 the north, at least, it seems to be true that S. vernalis is usually 

 found associated with 8, eernua and S. gracilis and is unknown where 

 these species fail. So far as Texas is concerned, however, there 

 is one serious objection to the theory that the original S. vernalis 

 was a hybrid and that is the season of anthesis of the supposed 

 parents. In Texas S. vernalis, as the name implies, is a vernal spe- 

 cies that blooms in April-June. S. eernua, from my records, blooms 

 in October in Texas. S. gracilis blooms there in spring and autumn. 

 Throughout its range S. ccrnua is an autumn or early winter bloomer. 

 Experimental evidence is much needed in connection with this prob- 

 lem and it would be well worth while to make crosses, between the 

 species that are suspected, during the next flowering season. 



Spiranthes eernua x gracilis. Plant 40-43 cm. tall. Stems wand- 

 like, about 3 mm. in diameter, pale green. Roots stout, up to (i 

 mm. in diameter, 1 dm. or more long. Leaves 4-0, the lowermost 

 ones withered at flowering time, 3-nerved, obliquely erect, alternate, 

 distichous, linear-lanceolate, 2 dm. long, 8 mm. wide, acute, margin 

 involute. Above the leaves are four or five closely appressed bracts 

 of which the lower ones are tubular and sheathing at base. Racemes 

 densely flowered, 8-13.5 cm. long, 1.7 cm. in diameter. Floral 

 bracts about mm. long, strongly concave, lanceolate, acuminate, 

 exceeding the ovary, margin inconspicuously scarious, tip appressed 

 to the flower. Flowers 7 mm. long, white with yellow lip, at right 

 angles to the rachis. Bracts and rachis pubescent, yellowish green 

 in hue. Stem sparingly pubescent below, densely and shortly so 

 above. Lateral sepals 7 mm. long with the margin strongly inrolled 

 forming a tube at the middle, wide-spreading as in 8. gracilis, not, as 

 in S. eernua, appressed to the lip with the points above its tip and 

 touching the petals, base strongly concave; upper sepal 8 mm. long, 

 closely appressed to the petals. Petals lightly adherent to the upper 

 sepal and equal to it in length, smooth, oblong, obtuse. Labellum 

 about 8 mm. long, sharply decurved above the middle, deeply grooved 

 along the median line beneath and in part covered with microscop- 

 ically minute spherical emergences, oblong, obtuse, the apical margin 

 Jacerate-dentate, disc papillose near the apex. Calli prominent, 

 smooth and glistening above, glandulose on the basal half; claw 



