Spiranthes pubicaulis is not closely allied to any pre- 
viously described species, but is somewhat related to JS. 
tenella L.. Wms. which is described below. 
Spiranthes tenella L. O. Williams sp. nov. 
Herbae terrestres, graciles, erectae, usque ad 35 cm. 
altae. Inflorescentia brevis, pauciflora. Sepalum dorsale 
elliptico-lanceolatum, acutum, trinervium. Sepala later- 
alia lineari-lanceolata, acuta, uninervia. Petala linearia, 
acuta, arcuata vel leviter sigmoidea, uninervia. Labellum 
oblongo-subpanduratum. Columna generis. 
Slender, erect, terrestrial herbs, up to about 35 cm. 
tall. Stems very slender, about 1—-1.5 mm. in diameter, 
with several semiamplexicaul, scarious, striated, acumi- 
nate sheaths. Inflorescence short, lax, few-flowered. 
Dorsal sepal about 8-10 mm. long and 2-3 mm. broad, 
elliptic-lanceolate, acute, 3-nerved. Lateral sepals about 
7-8 mm. long and 1.5-2 mm. broad, linear-lanceolate, 
acute, l-nerved. Petals 8-9 mm. long, about 1.5 mm. 
broad, linear, acute, arcuate or slightly sigmoid, 1-nerved. 
Lip about 9-10 mm. long and 5-6 mm. broad, oblong- 
subpandurate when expanded, both the apical and basal 
halves more or less rounded; terminal half squarrose 
above; basal half with pubescence extending from the 
base through the middle; claw about 1 mm. long. 
Mexico: near Guadalupe y Calvo, Chihuahua, longitude 105°36/ 
west, latitude 26°28’ north, at 2000-2500 meters altitude, lip snow 
white with yellowish brown veining, sepals and petals pink, veined 
Vandyke red, April 13, 1936, Juan G. [onzdles | 5027 (Tyrer in Herb. 
Ames No. 51244). 
Spiranthes tenella is more closely allied to Spiranthes 
pubicaulis than to any species previously described. 
Spiranthes tenuissima L. O. Williams sp. nov. 
Herbae terrestres, graciles, erectae, usque ad 30 cm. 
altae. Inflorescentia elongata, plusminusve densa. Sepa- 
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