lateralibus obliquis, lineari-oblongis, obtusis, usque ad 11 mm. 
longis, 2.3 mm. latis; petalis e cuneata basi dolabriformibus, 
obtusis, usque ad 9 mm. longis, 2.8 mm. latis; labello carnoso, 
rhombeo, angulis rotundatis, antice obtuso, supra basin margine 
incrassato, pubescenti, usque ad 10 mm. longo, 5 mm. lato; 
columna cylindrica, 4 mm. longa; ovario ovoideo, pubescenti, 
sessili, torto, usque ad 5 mm. longo. 
Mexico: Morelos, near Tlayacapan. Coll. Juan Gonzales 
2163! Type! (AMES). 
This new species is well represented in herbaria under the 
name of Spiranthes Arseniana Krz\. This confusion is due prim- 
arily to the material originally distributed under Arsene, 6671, 
the type number of S. Arseniana. | have examined the holotype 
which is in Montpellier, and it represents Pelexia Schaffneri 
(Rchb.f.) Schltr. A duplicate of the holotype number however, 
in the United States National Herbarium, Washington, D.C., is 
a specimen identical with the present new species. Obviously the 
Washington material is responsible for the previous misap- 
plication of the binomial, Spiranthes Arseniana. 
Mesadenella angustisegmenta Garay, sp. nov. 
Plantae terrestres, elatae, usque ad 30 cm. alta; radicibus 
fasciculatis, carnosis, pubescentibus; foliis basilaribus, plurimis, 
distincte petiolatis, petiolis canaliculatis, usque ad 6 cm. longis; 
lamina oblique ovato-elliptica, acuta vel subacuminata, usque 
ad 11 cm. longa, 5 cm. lata; scapo erecto, dimidio inferiori 
vaginato, dimidio superiori satis laxe spicato; bracteis lanceo- 
latis, acuminatis, usque ad 15 mm. longis, sursum decrescenti- 
bus; floribus virescentibus, parvulis, extus pubescentibus; sepalo 
postico anguste ovato, acuto, usque ad 5 mm. longo, 1.2 mm. 
lato; sepalis lateralibus oblique lineari-oblongis, obtusis, usque 
ad 7 mm. longis, 1.5 mm. latis; petalis lineari-oblanceolatis, 
acutis, usque ad 4.5 mm. longis, | mm. latis; labello anguste 
pandurato, parte superiori elliptico, subcrenulato, carnosulo- 
tuberculato, parte inferiori sagittato, disco in medio pubescenti; 
toto labello usque ad 6 mm. longo, 2 mm. lato; columna gracill, 
facie pubescenti, usque ad 3 mm. longa, basi in pedem 
285 
