324 ORCHIDACEAE 
all free and separate. Lip free, concave below, constricted below the dilated and petal-like 
upper portion. Column short, erect. Anther erect, operculate, its sacs contiguous. Pollen- 
masses granulose, 2-parted, becoming attached to the glandular stigma-beak. Capsules 
oblong, beakless. 
1. Epipactis gigantéa Dougl. Stems 3-12 dm. tall, simple, often slightly zigzag : 
leaf-blades lanceolate to ovate-lanceolate or ovate near the base of the stem, 1-1.5 dm. long, 
or shorter above, the lower ones clasping or sheathing the stem, the upper merely sessile : 
bracts similar to the leaves but much smaller: raceme pubescent: perianth greenish, pur- 
ple-veined : sepals lanceolate to ovate-lanceolate, 12-18 mm. long: lateral petals somewhat 
smaller than the sepals: lip about as long as the sepals, the concave portion with erect 
margins and callous-thickened nerves below, the upper portion ovate or lanceolate-ovate, 
entire: capsules oblong, 15-20 mm. long. 
In damp shaded places, British Columbia to California and Texas. Summer. 
23. ARETHUSA L. 
Caulescent herbs, with corm-like rootstocks. Leaves mostly reduced to scales, one with 
a linear blade sometimes near the top of the stem. Flowers usually solitary and terminal. 
Sepals cohering at the base, converging and hooded. Lateral petals similar to the sepals. 
Lip broadly dilated, recurved, spreading above, crested on the inner face. Column nar- 
row, coherent to the lip below, winged and dilated at the apex. Anther incumbent on the 
column: sacs approximate.  Pollen-masses 4, two in each sac, powdery-granular. Capsule 
elongated, erect, angled or ribbed.  Rosr-rir. 
1. Arethusa bulbósa L. Corm 1-2 cm. in diameter: stems scape-like, 1-3 dm. 
tall: leaves various, one basal with a linear blade, 1-1.5 dm. long, others mostly mere 
sheathing scales: flowers solitary or rarely 2, subtendéd by 2 small unequal bracts : peri- 
anth showy, rose-purple, 3-6 mm. long, erect: sepals linear or oblong, 3-4 cm. long ; lat- 
teral ones curved : lateral petals often slightly shorter than the sepals: lip drooping, 2.5- 
3 mm. long, dilated to the toothed or fringed apex, the face often blotched, bearded, 
crested with 3 white hairy lines: capsule 2-2.5 em. long, strongly 6-ribbed. 
In bogs, Newfoundland to Minnesota, the mountains of North Carolina, and Indiana. Spring. 
24. VANILLA Sw. 
Vines climbing by aerial roots. Stems elongated, often with very long internodes. 
Leaves fleshy or leathery : blades sessile or slightly petioled, jointed at the base, rarely 
wanting. Flowers in axillary racemes. Perianth showy.  Sepals and lateral petals 
nearly similar, distinct, spreading. Lip dilated above, adnate to the naked column. 
Anther large, hemispheric, or conic, incumbent.  Pollen-masses rather granular. Capsule 
fleshy, often elongated, sometimes very fragrant, dehiscent, or indehiscent. 
1l. Vanilla planifólia Andr. A vine climbing to a height of several m. Stems 
terete, branching: leaf-blades leathery, oblong or elliptic-oblong, 10-18 cm. long, acute, 
sessile or nearly so: bracts ovate, acute: perianth green, 5-6 em. long, not showy : sepals 
linear-spatulate, slightly involute: lateral petals rather similar to the sepals but shorter 
and narrower, more delicate : lip shorter than the sepals ; blade cornucopia-like, toothed, 
crested : column extending to the toothed portion of the lip: capsules'cylindric, elongated, 
1-2 dm. long, very fragrant when partially dry. 
In forests, peninsular Florida and tropical Ameriea. Also widely cultivated. 
25. ACHROANTHES Raf. 
Caulescent herbs, with short corms. Leaves mostly reduced to scales, and one normally 
with an expanded blade and sheathing base. Flowers ina terminal raceme. Perianth white 
or greenish, not showy. Sepals distinct, spreading, the 2 lateral equal. Lateral petals very 
narrow or filiform, spreading. Lip broad, cordate or auricled at the base. | Anther 2- 
celled, erect or between the auricles of the lip. Pollen-masses 4, two in each sac, waxy, 
tailless and without glands, cohering at the apex. Column embraced by the lip. Capsule 
ribbed, beakless. [Microstylis Nutt.] The plants flower in the summer. ADDER’s MOUTH. 
Lip 3-toothed at the broad apex. 1. A. unifolia. 
Lip entire at the acute apex 
Leaf solitary : pedicels shorter than the capsules. 2. A. monophylla. 
Leaves 2: pedicels as long as the capsules. - 3. A. Floridana. 
