506 ORCHIDACE^E. (ORCHIS FAMILY.) 



at the base nipple-shaped. (Also S. Beckii, LindL, at least as to the Northern 

 plant.) — Hilly woods and sandy plains: common. July -Oct. — Perianth 

 barely l£"- 2" long. 



6. S. simplex, n. sp. Root a solitary oblong or spindle-shaped tuber ; no 

 leaves at flowering time; scape 5' -9' high, bearing a small narrow (rarely 1- 

 sided) spike of very small flowers (perianth 1"-H" long) ; lip thin, white, obo- 

 vale-oblong, the apex eroded and crisped, the callosities at the base slender. — 

 Dry, sandy soil, E. Mass. (Nantucket, Dr. Bobbins), New Jersey, and Delaware, 

 Wm. M. Canby. Aug., Sept. — Spike 1 ' - 3' long. 



5. LISTERA, R. Brown. Twatblade. 



Sepals and petals nearly alike, spreading or reflexed. Lip mostly drooping, 

 longer than the sepals, 2-lobed or 2-cleft. Column wingless : stigma with a 

 rounded beak. Anther borne on the back of the column at the summit, erect, 

 ovate : pollen powdery, in 2 masses, joined to a minute gland. — Roots fibrous. 

 Stem bearing a pair of opposite sessile leaves in the middle, and a spike or ra- 

 ceme of greenish or brownish-purple small flowers. (Dedicated to Martin Lister, 

 an early and celebrated British naturalist.) 



* Column very short. (Sepals ovate, reflexed : plants delicate, 4' - 8' high.) 



1. L. COrdata, R. Brown. Leaves round-ovate, somewhat heart-shaped 

 (J'— 1' long) ; raceme smooth; flowers minute, crowded, on pedicels not longer than 

 the ovary ; lip linear, twice the length of the sepals, 1 -toothed on each side at the 

 base, 2-cleft. — Damp cold woods ; from Penn. northward. June, July. (Eu.) 



2. L. australis, Lindl. Leaves ovate; raceme loose and slender; flowers 

 very small, on minutely glandular-pubescent pedicels twice the length of the ovary ; lip 

 linear, 3-4 times the length of the sepals, 2-parted, the divisions linear-setaceous. 

 — Damp thickets, New Jersey to E. Virginia and southward. June. 



* * Column longer, arching or straightish. 



3. L. COnvallarioides, Hook. Leaves oval or roundish, and sometimes 

 a little heart-shaped (l'-lj* long) ; raceme loose, pubescent; flowers on slen- 

 der pedicels ; lip wedge-oblong, 2-lobed at the dilated apex, and 1 -toothed on 

 each side at the base, nearly twice the length of the narrowly lanceolate spread- 

 ing sepals, purplish, $' long. (Epipactis convallarioides, Swartz.) — Damp 

 mossy woods, along the whole Alleghany Mountains, to Penn., also Maine to 

 Lake Superior, and northward. — Plant 4' -9' high. 



6. ARETHUSA, Gronov. Arethusa. 



Flower ringent ; the lanceolate sepals and petals nearly alike, united at the 

 base, ascending and arching over the column. Lip dilated and recurved spread- 

 ing towards the summit. Column adherent to the lip below, petal-like, dilated 

 at the apex. Anther lid-like, terminal, of 2 approximate cells : pollen-masses 

 powdery-granular, 2 in each cell. — Beautiful low herbs, consisting of a sheathed 

 scape from a globular solid bulb, terminated usually by a single large rose-pur- 

 ple flower. Leaf solitary, linear, nerved, hidden in the sheaths of the scape, 

 protruding after flowering. (Dedicated to the Nymph Arethusa.) 



