A NEW PLEUROTHALLIS FROM MEXICO 
BY 
CHARLES SCHWEINFURTH 
AmonG the interesting orchids collected by EK. Matu- 
dain the south of Mexico is the following one belonging 
to the large group of rather closely allied species center- 
ing around Pleurothallis cardiothallis Reichb.f. Its floral 
characters, however, apparently do not permit of its in- 
clusion in any known species. 
Pleurothallis Matudiana C.Schweinfurth sp.nov. 
Herba mediocris, caespitosa. Caules numerosi, basi 
et infra medium vagina tubulari ornati. Folium singu- 
lum, saepissime erectum, oblongo-ovatum vel ovatum, 
basi cordatum. Inflorescentiae uniflorae, fasciculatae. 
Flores parvi, ringentes, bilabiati. Sepalum dorsale valde 
concavum, ovatum. Sepala lateralia in laminam acriter 
bidentatam late ovatam connata. Petala anguste linearia, 
inferne crenulata. Labellum ovato-oblongum, crassissi- 
mum, acutum. Columna subgeneris. 
Plant medium-sized, up to about 82 cm. tall to the 
tip of the erect leaf. Roots fibrous, numerous, filiform, 
glabrous. Stems caespitose, numerous, up to about 24 
cm. tall, slender, provided at the base and below the mid- 
dle with a tubular-cylindrie scarious evanescent sheath. 
Leaf solitary, erect or spreading, oblong-ovate or ovate, 
strongly cordate at the base, about 7.7-11 em. long in- 
cluding the basal auricles, up to 8.7 cm. wide, acute or 
acuminate with a minutely tridenticulate tip, coriaceous. 
Flowers in the sinus between the basal lobules of the leat, 
surrounded by asmall conduplicate spathe. Flower small, 
ringent, bilabiate. Dorsal sepal concave, ovate, acute, 
about 8.7 mm. long in natural position and 5.7 mm. wide, 
3-nerved. Lateral sepals connate into a sharply bidentate 
{ 102 | 
