316 



ORCHIDACEAE (ORCHIS FAMILY) 



10. LISTERA R. Br. TWAYBLADE 



Sepals and petals nearly alike, spreading or reflexed ; lip mostly drooping, 

 longer than the sepals, 2-lobed or 2-cleft at the summit. Column wingless. 

 Stigma with a rounded beak ; anther borne on the back of the column at the 

 summit, erect, ovate ; pollen powdery, in two masses, joined to a minute gland. 

 Roots fibrous. Stem bearing in the middle a pair of nearly opposite sessile 

 leaves. The small flowers greenish or madder-purple in a terminal raceme. 

 (Dedicated to Martin Lister, 1038-1711, a celebrated English naturalist.) 



* Column very short (0.5 mm. or less) lip not dilated above. 

 *- Lip with a tooth on each side at base ; raceme glabrous. 



1. L. cordata (L.) R. Br. Leaves round-ovate, somewhat heart-shaped, 

 12-25 mm. long; stem pubescent just above the leaves; flowers about 3 mm. 

 across, on pedicels not longer than the ovary ; lip narrowly oblong, 

 2-cleft. Mossy woods and swamps, Lab. to N. J., w. to Mich., 

 Col., and Cal., north w. to the Arctic coast. (GreenL, Iceland, 

 Eu., and Japan.) FIG. 630. 



630 L cordata 

 x J 2 / 



*- *- Lip not toothed at base ; raceme glandular. 



2. L. australis Lindl. Leaves ovate ; raceme loose and slen- 

 der ; flowers small, on minutely glandular-pubescent pedicels which 

 equal or exceed the glabrous ovaries; lip linear, 6-10 mm. long, 

 cleft one third to two thirds the way down into linear-setaceous divisions. 

 Shady woods, La. and Fla. to N. J. ; Oswego Co., N. Y. ; Ottawa, Out. 



* * Column 2-3 mm. long. 

 - Lip auriculate at base, more or less ciliate. 



3. L. auriculata Wiegand. Leaves elliptic-oval or elliptic-ovate, 35-50 mm. 

 long, inserted above the middle of the stem ; flowers numerous, in a loose raceme ; 

 rhachis pubescent ; pedicels glabrous, mostly shorter than the 



glabrous ovaries ; lip 6-8 mm. long, slightly ciliate, oblong, cleft 

 one third to one fourth of its length, auricles incurved. Cedar 

 swamps and mossy banks, e. Que. to n. N. II. and n. Vt. 

 FIG. 631. 



-t- -i- Lip not auriculate at base. 



-< Ovary glandular. * i%- 



4. L. convallarioides (Sw.) Torr. Leaves oval or roundish and sometimes 

 slightly heart-shaped, 3-5 cm. long; raceme many-flowered, loose; rhachis 

 densely glandular-pubescent ; pedicels glandular, slightly longer than the ovaries ; 



lip 9-11 mm. long, ciliate on the margin, narrowly cuneate, 

 retuse, lobes rounded, on each side of base a short triangular 

 tooth. Moist woods, Nfd. to n. N. E., Mich., and the Kocky 

 Mts., westw. and northw. FIG. 632. 



. -M. Ovary glabrous. 



5. L. Smallii Wiegand. Leaves borne at or below the middle 

 of the stem, 15-25 mm. long, ovate-reniform, mucronate, often 

 apiculate ; raceme loose, few-flowered; rhachis glandular: pedicels glabrous, 

 (imaling or exceeding the ovaries in length ; lip 9mm. long, not ciliate, broadly 

 obovate, cleft at the apex, on each side of base a curved oblong obtuse tooth. 

 Damp woods in the nits., Pa. to N. C. (E. Asia.) 



631. L. auriculata 



L. convalla- 

 rioides xl. 



11. CORALLORRHiZA [Iluller] R. Br. CORAL ROOT 



Perianth somewhat ringrnt. gibbous or obscurely spurred at base. Sepals 

 and petals oblong-lanceolate, nearly alike, 1-.>-nerved ; lateral sepals ascending, 

 forming with the lip the gibbosity or short spur which is mostly adnate to the 



