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. 

 Sticrma 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., northw. to the Arctic coast. (Greenl, Iceland, 

 Eu., and Japan.) Fig. 630. 



L. cordata 

 X 12/3. 



•*- -t- 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, Ont. 



* * Column 2-3 mm. long. 



-t- 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 ; jjedicels 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. H, and n. Vt. 

 Fig. 631. 



•*- •»- Lip not auriculate at base. 



++ Ovary glandular. 



631. L. auriculata 



4o 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 Rocky 

 Mts., westw. and northw. Fig. 632. 



++ -^ Ovary glabrous. 



632. L. convalla- , ,, 



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



of the stem, l.')-20 mm. long, ovate-reniform, mucronate, often 

 apiculate ; raceme loo.se, few-flowered ; rhachis glandular : pedicels glabrous, 

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

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

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



11. CORALLORRHIZA [Ilaller] R. Br. Coral Root 



Perianth somewliat riiigent, gibbous or obscurely spurred at ba.se. Sepals 

 and petals oblong-lanceolate, nearly alike, l—'Vnerved ; lateral sepals ascending, 

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



