ORCHIDACEAE. 87 



1. P. ophioglossoid.es (L.) Ker. Stem 2-5 dm. tall: blades of the cauline 

 leaves oblong-lanceolate to elliptic, 3-8 cm. long: lateral sepals linear-elliptic 

 or narrowly oblong, 16-20 mm. long, acute: petals elliptic or oblong-cuneate, 

 14-16 mm. long, obtuse : lip longer than the petals, blunt at the rounded fringed 

 apex. E. S. Bare, in swamps. Schists. Sum. 



11. TRIPHORA Nutt. Caulescent herbs, with fleshy tubers. Leaves 

 several, with relatively br.oad blades. Flowers several, axillary to leaf-like 

 bracts. Perianth mainly purple. Sepals nearly equal, about as long as the 

 petals. Petals about as broad as the sepals, but narrower at the base. Lip 

 dilated above the claw, 3-lobed, crestless. Capsules drooping. 



1. T. trianthophora (Sw.) Rydb. Stem 5-30 cm. tall: leaf -blades suborbicular 

 to ovate, 520 mm. long: flowers nodding: lateral sepals linear-oblong to 

 linear-elliptic, 13-15 mm. long: lip 12-14 mm. long, the claw shorter than the 

 blade: capsules 10-14 mm. long. W. Rare, in rich woods near Shenk's 

 Ferry. Limestones. Sum. NODDING- CAP. 



12. ARETHUSA [Gronov.] L. Scapose herbs with corms. Leaves mere 

 elongate sheathing scales, or the upper one sometimes with a narrow blade. 

 Flower usually solitary at the top of the scape. Perianth mainly rose-purple. 

 Lateral sepals slightly curved. Petals similar to the lateral sepals but shorter. 

 Lip dilated, recurved, crested. Capsule erect. 



1. A. bulbosa L. Leaf with a linear blade 10-15 cm. long: scape 1-3 dm. 

 tall: lateral sepals broadly linear to narrowly oblong, 35-43 mm. long, acute: 

 lip 25-30 mm. long, with 2 shallow lateral lobes and a larger middle lobe, 

 toothed or fringed at the apex: capsule 20-25 mm. long. E. S. Rare, in 

 swamps, near Beartown and Smithville. Schists, quartzite. Spr. 



13. IBIDIUM Salisb. Caulescent herbs. Leaves various, the basal and 

 lower cauline with narrow blades, the upper cauline leaves mere sheathing scales. 

 Flowers in a terminal spiral spike. Perianth pale. Median sepal and petals 

 coherent: lateral sepals erect. Lip erect, or spreading at the tip, bearing 2 

 basal callosities, the lower portion folded around the very short column. Stigma 

 with a 2-f orked beak. LADIES '-TRESSES. 



Flowers merely alternate, apparently secund from the spiral twisting of the rachis. 

 Stem scaly : leaves basal ; blades short, broad, fugaceous. 



Root solitary : lip white, of an ovate type, erose-crisped from below the 



middle to the apex. 1. /. Beckii. 



Roots clustered : lip green, except the crisped margin, of 



an oblong type, wavy-crisped at the apex. 2. /. gracile. 



Stem leafy below : blades of the leaves narrow, elongate, 



persistent. 

 Lip of an ovate type, dilated at the base, pubescent 



without. 3. /. vernale. 



Lip of an oblong type, not dilated, glabrous without. 4. /. praecox. 



Flowers 3-several-ranked, the rachis not conspicuously twisted. 

 Lip of an ovate type, the callosities prominent, usually 



curved : plants usually fall-flowering. 5. I. cernuum. 



Lip of a quadrate type, the callosities imperfect, mostly in 



the edge of the lip-base: plants usually vernal-flowering. 6. /. plantagineum. 



1. I. Beckii (Lindl.) House. Stem 1-3 dm. tall, from a single root: blades 

 of the basal leaves ovate or oblong, 1-3 cm. long, early decaying: perianth 

 white: lateral sepals broadly lanceolate, about 3 mm. long: petals broadly 

 spatulate or oblong-spatulate : lip ovate to orbicular-ovate, 2.5-3 mm. long, 

 the callosities directed backward. Occasional, in dry or sandy soil. Sum. 

 and fall. 



2. I. gracile (Bigel.) House. Stem 2-6 dm. tall, from a cluster of roots: blades 

 of the basal leaves oblong, elliptic, or ovate-lanceolate, 1.5-5 cm. long, early 



