GENUS 3. ACANTHUS FAMILY. 
1. Dianthera americana L. Dense- 
flowered Water Willow. Fig. 3893. 
Dianthera americana L. Sp. Pl. 27. 1753. 
Perennial, glabrous; stem erect, grooved and 
angled, slender, usually simple, 1°-3° high, or 
sometimes 6° long when growing in water. 
Leaves lanceolate or linear-lanceolate, grad- 
ually acuminate, 3’-6’ long, 3-8” wide, entire, 
narrowed at the base into short petioles, or 
sessile; flowers violet, or nearly white, capi- 
tate-spicate at the ends of slender axillary 
peduncles which are shorter than or equal to 
the leaves; bractlets linear-subulate, shorter 
than the flowers; corolla 5-6” long, its tube 
shorter than the lips, the base of the lower 
lip rough and palate-like; capsule 6” long, 
exceeding the calyx, its stipe about the length 
of the slightly compressed body. 
In water_and wet places, Quebec to Ontario, 
Michigan, Georgia and Texas. May—Aug. 
2. Dianthera ovata Walt. Loose-flow- 
ered Water Willow. Fig. 3894. 
Dianthera ovata Walt. Fl. Car. 63. 1788. 
Perennial, glabrous; stem ascending or erect 
from a horizontal base, slender, 6-20’ high, 
simple, or sparingly branched. Leaves short- 
petioled, or sessile, ovate, oblong or oval, 1’-3’ 
long, 8-18” wide; flowers opposite in loose 
slender-peduncled axillary spikes, which be- 
come 17-3’ long; peduncles shorter than or 
but little exceeding the leaves; calyx-segments 
narrowly linear, much longer than the bracts 
and bractlets; corolla pale purple, 4’-5” long; 
capsule about 6” long. 
In wet soil, especially along streams, southern 
Virginia to Florida. Records from Arkansas and 
Texas apply to the following species. June~Aug: 
y 
3. Dianthera lanceolata (Chapm.) Small. 
Narrow-leaved Water Willow. Fig. 3895. 
D. ovata lanceolata Chapm. Fl. S. States 304. 1860. 
D. lanceolata Small; Britton, Man. 855. 1901. 
Perennial, puberulent; stem erect or spreading, 
more or less branched, 4-12’ long. Leaves linear 
to linear-elliptic or elliptic-lanceolate, 13-4’ long, 
more or less acuminate, undulate, sessile or nearly 
so; flowers in interrupted slender spikes 13’-4’ 
long; calyx-segments narrowly linear, 23’-3%” 
long; corolla whitish or pale-purple, about 5” 
long, the lips nearly as long as the tube, which 
is saccate near the base, the upper lip truncate 
or retuse, the lower one 3-lobed, the middle lobe 
truncate or retuse, the lateral ones obtuse; cap- 
sule 7’’-8” long, the body as long as the stipe-like 
base or shorter. 
In swamps and low grounds, Missouri to Tennessee, Florida and Texas. June—Sept. 
4. DIAPEDIUM Konig; Konig & Sims, Ann. Bot. 2: 189. 1806. 
[DicrieTerA Juss. Ann. Mus. Paris, 9: 267. 1807.] 
Erect or diffuse branched pubescent or glabrous herbs, with entire petioled leaves, and 
blue red or violet flowers, subtended by involucres of 2-4 distinct or connate bracts, the 
