1914] : PFEIFFER—THISMIA AMERICANA 123 
this, the finding in the Chicago region of a form closely allied with 
these last is of decided interest. 
Thismia (BAGNISIA) americana, nov. sp.—Herbae saprophy- 
ticae, tenerae, hyalinae, caulibus simplicibus erectis, radicibus 
elongatis glabris foliis bracteiformibus. Pedunculi uniflori, erecti 
vel curvati, o.3-1cm. longi. Flores subtiliter virides 0o.8- 
1.5 cm. longi, circiter 6mm. diametro. Perianthii tubus superus, 
obovoideo-oblongus, ore constrictus, lobis 6, quorum interiores 
tres apice conniventes, calyptram 3-stipitatam formantes; lobi 
alterni equales sed liberi. Stamina 6, fauci affixa; intra tubum 
deflexa filamentis brevissimis, connectivis maximis membranaceis 
in tubum deflexum connatis; antherae biloculares, loculis parvis 
distinctis parallelis, rima longitudinale dehiscentis. Ovarium 
breve, latum, 1-loculare, placentis 3 parietalibus, in cavo ovarii 
a pariete solutis. Stylus brevis, crassus, apice trifidus. Ovula 
humerosa, minuta, anatropa. Fructus turbinato-cupulatus, peri- 
anthii circumscisse deciduo truncatus, margine parum elevato 
cinctus. Semina numerosa, parva, oblonga, albuminosa; testa 
tenuis, hyalina, reticulata. Embryo parvissimus, in albumine 
inclusus. 
Chicago, Ill., in open prairie, N. E. PFEIFFER. 
The plant consists of a white root system, from which arise erect 
simple floral axes. The roots are about 1mm. in diameter and 
vary greatly in length. The flowers are 0.8-1.5 cm. high, borne 
n an axis 0.3-1.0cm. high. The perianth tube is conspicuously 
G-nerved and with 6 minor nerves. The 3 petals, approximately 
equal in length to the 3 sepals, are connate at the apex. The 
mouth of the perianth tube is closed by a disk of tissue, with a 
central circular aperture surrounded by araised ring. To this ring 
the 6 stamens are affixed, and are united into a tube which hangs 
downward inside the perianth tube. This stamen tube, largely 
made of the broadened connectives, bears the pollen sacs on the 
Side toward the perianth wall. 
The inferior ovary is one-celled, with three placentae which 
Soon become free from the walls, appearing in a central plane as 
three free columns. The ovules are anatropous, numerous, and 
