302 FLORA. 



appearing above the anther. In moist woods, Lab. to Alaska, N. J. and Ore. 

 Also in Europe and Asia. June-Aug. 



5. Listera australis Lindl. SOUTHERN TWAYBLADE. (I. F. f. 1130.) Stem 

 slender, 1-2.5 dm. high, more or less pubescent above. Leaves ovate, acutish, 

 mucronate, glabrous, shining, 14-25 mm. long, 3-7 -nerved; raceme 5-7 cm. long, 

 loosely 8- 1 5 -flowered; flowers yellowish green with purplish stripes; sepals and 

 petals minute; lip 6-iomm. long, 2-parted, split halfway to the base or deeper, 4-8 

 times as long as the petals, its segments linear-setaceous; column very small. In 

 bogs, N. Y. and N. J. to Fla., and Ala. and La. Feb. -June. A third leaf is rarely 

 borne below the flowers. 



19. PERAMIUM Salisb. 



Herbs with bracted erect scapes, the leaves basal, tufted, often blotched with 

 white, the roots thick fleshy fibres. Flowers in bracted spikes. Lateral sepals 

 free, the upper one united with the petals into a galea. Lip sessile, entire, round- 

 ish ovate, concave or saccate, without callosities, its apex reflexed. Anther with- 

 out a lid, erect or incumbent, attached to the column ^by a short stalk; pollinia I 

 in each sac, attached to a small disk which coheres with the top of the stigma, com- 

 posed of angular grains. About 25 species, widely distributed in temperate and 

 tropical regions. 



Lip evidently saccate. 



Spike loosely flowered ; lip with recurved margins. 



Spike i-sided ; beak shorter than the stigma proper. 



Blotches white, mostly along the cross- veins ; galea strongly recurved. 



1. P. ophioides. 

 Blotches pale, mostly along the ribs ; galea not strongly recurved. 



2. P. repens. 

 Spike spiral ; beak as long as the stigma proper or longer. 3. P. tessellatum. 



Spike dense, not i-sided ; margins of the lip not recurved. 4. P. pubescens. 



Lip scarcely saccate, with incurved margins. 5. P. Menziesii. 



1. Peramium ophioides (Fernald) Rydb. WHITE-BLOTCHED RATTLESNAKE 

 PLAINTAIN. Scape 1-2 dm. high, glandular-pubescent. Leaf-blade 1-2 cm. 

 long, broadly ovate, abruptly contracted into a short winged petiole, dark green, 

 generally with the white blotches most conspicuous along the cross-veins; flowers 

 greenish white, 4-5 mm. long; galea concave with a short strongly recurved tip; 

 lip deeply saccate, with recurved margins and tip; anthers blunt. In cold, mossy 

 woods from Prince Edward Island to Man. and N. Car. July-Sept. [Goody era 

 repens ophioides Fernald.] 



2. Peramium repens (L.) Salisb. NORTHERN RATTLESNAKE PLAINTAIN. 

 (I. F. f. 1131.) Scape 1-2.5 dm. high. Leaves ovate, the blade 1-3 cm. long, 

 somewhat reticulated with pale blotches, tapering into a sheathing petiole; spike 

 short, i-sided; flowers greenish white, 5-6 mm. long; galea concave, ovate, with a 

 short spreading or slightly recurved tip; lip saccate, with a narrow recurved or 

 spreading apex; column very short; anther 2-celled, blunt.* In woods, N. S. to 

 Alaska (?), south to Mass, and Colo. Also in Europe and Asia. July-Aug. 



3. Peramium tessellatum (Lodd.) Rydb. CHECKERED RATTLESNAKE PLAN- 

 TAIN. Scape 2 dm. high or more. Leaves from 2 to 7 mm. long, ovate to oblong- 

 lanceolate, dark green with pale blotches, or sometimes not blotched; spike about 6 

 cm. long; flowers 6-8 mm. long; galea with a slightly recurved tip; lip less saccate 

 than in the preceding and with the tip less recurved ; anthers acuminate; beak as 

 long as the body of the stigma or longer. In woods, seldom in bogs, from Newf. 

 to Lake Superior, south to N. Y. Aug. [Goody era tessellata Lodd.] 



4. Peramium pubescens (Willd.) MacM. DOWNY RATTLESNAKE PLANTAIN. 

 (I. F. f. 1132.) Usually larger than the preceding species, scape 15-60 cm. high, 

 densely glandular-pubescent, bearing 5-10 lanceolate scales. Leaves 2-5 cm. long, 

 15-25 mm. wide, strongly white-reticulated, oval or ovate; spike not i -sided; 

 flowers 6-8 mm. high, greenish white; lateral sepals ovate; galea ovate, its short 

 tip usually not recurved; lip strongly saccate with a short broad obtuse recurved 

 or spreading tip. In dry woods, Newf. to Ont. and Minn. , south to Fla. and Tenn. 

 July-Aug. 



