Genus 3. 



ACANTHUS FAMILY. 



1. Dianthera americana L. Dense- 

 flowered Water Willow. Fig. 3893. 



Dianthera americana L. Sp. PI. 27. 1753. * 



Perennial, glabrous ; stem erect, grooved and 

 angled, slender, usually simple, i-3 high, or^ 

 sometimes 6 long when growing in water. <0 

 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'-2o' high, 

 simple, or sparingly branched. Leaves short- 

 petioled, or sessile, ovate, oblong or oval, i's' 

 long, 8"-i8" wide ; flowers opposite in loose 

 slender-peduncled axillary spikes, which be- 

 come i'-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"-S" 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. 



3. Dianthera lanceolata (Chapm.) Small. 

 Xarrow-leaved Water Willow. Fig. 3895. 



D. ovata lanceolata Chapm. Fl. S. States 304. i860. 

 D. lanceolata Small; Britton, Man. S55. 1901. 



Perennial, puberulent ; stem erect or spreading, 

 more or less branched, 4-12' long. Leaves linear 

 to linear-elliptic or elliptic-lanceolate, 1Y-4' long, 

 more or less acuminate, undulate, sessile or nearly 

 so; flowers in interrupted slender spikes 1 1 '-4' 

 long; calyx-segments narrowly linear, 2i"~3i" 

 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 Konlg; Konig & Sims. Ann. Bot. 2: 189. 1806. 

 [Dicliptera 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 



