194 CYPERACEAE 
achenes plump-lenticular, orbicular-obovoid, pale, 0.5-0.8 mm. long, reticulated, pinched 
at the base, each with a depressed sessile tubercle. 
In moist pine lands, South Carolina to Florida. Also in the Bahamas and the West Indies. Spring 
and summer. 
7. Rynchospora Chapmánii M. A. Curtis. Perennial, pale green. Stems densely 
tufted, 2-6 dm. tall, filiform: leaves resembling the stem but more slender : spikelets ag- 
gregated into a solitary terminal cluster 1-1.5 em. broad, spindle-shaped, 3-4 mm. long, 
whitish, 1-flowered : scales 5, acuminate or awn-tipped, the upper one fertile: perianth- 
bristles wanting: achenes lenticular, oval, barely 1.5 mm. long, smooth and shining, each 
with a depressed-deltoid tubercle i-i as long as the achene. 
In low pine lands, South Carolina to Florida and Louisiana. Spring to fall. 
8. Rynchospora pallida M. A. Curtis. Rootstocks slender: stems triangular, 5-6 
dm. tall: leaves various, the lower reduced to scales; blades 1-2.5 mm. wide, nearly 
smooth : spikelets numerous, spindle-shaped, 4-6 mm. long, aggregated in a compound 
terminal head, or occasionally also in a cluster from the upper axil: bracts with subulate 
blades: scales pale greenish brown, lanceolate, acuminate: perianth-bristles minute and 
early deciduous, or wanting : stigmas 2 : achenes lenticular, obovoid-oblong, smooth, brown, 
shining, 2 mm. long, or nearly so, each with a minute depressed tubercle. 
In pine-land bogs, New Jersey to North Carolina. Summer and fall. 
9. Rynchospora oligántha A. Gray.  HRootstocks short: stems almost thread-like, 
leafy toward the base, 1.5-4 dm. tall: leaves few; blades filiform: spikelets solitary or 
2-4 together, terminal, narrowly oblong, acute, 6-8 mm. long, subtended by 1 or 2 filiform 
bracts: scales ovate, pale brown, acute, cuspidate: perianth-bristles usually 6, densely 
plumose below the middle: stigmas 2: achenes obovoid, 2 mm. long or nearly so, obtuse, 
pale brown, dull, transversely wrinkled ; tubercle with a flat depressed border and a 
flattened conic acute projection. 
In wet sandy soil, Delaware to Florida and Texas. Summer. 
10. Rynchospora plumósa Ell. Perennial, bright green. Stems tufted, 1.5-3.5 
dm. tall, slender and wiry : leaves few ; blades filiform, curving in age: spikelets oblong- 
ovoid, 2.5-3.5 mm. long, in 3 or 4 lax clusters at the top of the stem: scales broadly ovate 
or oval : perianth-bristles 6, plumose nearly or quite to the top : achenes orbicular-obovoid, 
nearly 2 mm. long, including the depressed conic glabrous tubercle, strongly wrinkled. 
In dry pine lands, South Carolina to Florida and Louisiana. Spring to fall. 
11. Rynchospora intermédia (Chapm.) Britton. Perennial, bright green. Stems 
tufted, 3-7 dm. tall, stout: leaves numerous at the base of the stem; blades 1-2 mm. 
broad, more or less involute, with roughish margins: spikelets 3-4 mm. long, in 4-6 
clusters, forming a more or less interrupted terminal spike-like inflorescence : perianth- 
bristles plumose nearly or quite to the top: achenes obovoid, transversely wrinkled, more 
or less grooved, fully 2 mm. long; tubercle depressed, conic, pubescent. [R. plumosa var. 
intermedia Chapm. ] 
In pine lands, Florida. Spring to fall. 
12. Rynchospora semiplumósa A. Gray. Perennial, bright green. Stems tufted, 
2.5-7 dm. tall, rather rigid: leaves rather numerous at the base of the stem; blades 
1.5-2.5 mm. wide, often with roughish margins : spikelets crowded into a solitary terminal 
head, or with an additional cluster farther down the stem : perianth-bristles plumose below 
the middle or only near the base : achenes globose-obovoid, wrinkled, 1.5 mm. long ; tuber- 
cle broadly conic, glabrous. 
In pine lands, Georgia and Florida to Louisiana and Texas. Spring to fall. 
13. Rynchospora alba (L.) Vahl. Pale green. Rootstocks short: stems slender 
or filiform, glabrous, 1.5-5 dm. tall : leaves bristle-like or slender, 0.5-1 mm. wide, shorter 
than the stem : spikelets in 1—4 dense corymbose clusters, narrowly oblong, acute at both 
ends, 4-6 mm. long : scales ovate or ovate-lanceolate, white or pale green, acute: perianth- 
bristles 9-15, downwardly barbed, slender, about as long as the achene and tubercle: 
achenes obovoid-oblong, fully 1.5 mm. long, smooth, pale brown, lenticular ; tubercle lan- 
ceolate, flat, $ as long as the achene. 
In bogs, Newfoundland to Alaska, Florida, Kentucky, Minnesota and Oregon. Also in northern 
Europe and Asia. Summer.—A variety ranging from Georgia and Florida to Texas, with stouter stems, 
15-24 bristles and clusters of spikelets sometimes 3 em. broad, is R. alba mácra Clarke. 
14. Rynchospora glomeràta (L.) Vahl. Deep green. Rootstocks slender: stems 
smooth, 3-10 dm. high: leaves shorter than the stem ; blades flat. 2-4 mm. wide, rough- 
margined: spikelets in 3-7 corymbose-capitate axillary clusters, oblong, narrowed at both 
ends, 3-4 mm. long: scales lanceolate, dark brown: perianth-bristles 6, downwardly 
