204 



ACANTHACEAE. 



[Vol. III. 



I. Dianthera Americana L. 

 Dense-flowered Water Willow. 

 C^'ig- 3374-) 

 Dianthera Americana L. Sp. PI. 27. 1753. 



Perennial, glabrous; stem erect, grooved 

 and angled, slender, usually simple, i°-3° 

 high. Leaves lanceolate or linear-lanceo- 

 late, gradually acuminate, 3'-6' long, 3"- 

 S" wide, entire, narrowed at the base into 

 short petioles, or sessile; flowers violet, or 

 nearly white, capitatc-spicate at the ends of 

 slender axillary peduncles which are shorter 

 than or equal the leaves; bractlets linear- 

 subulate, shorter than the flowers; corolla 

 5"-6" long, its lube 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, Ontario and Michi- 

 gan to Georgia and Texas. May-Aug. 



2. Dianthera ovata Walt. Loose-flowered Water Willow 



Dianlkera ovata Walt. Fl. Car. 63. 17S8. 



Dianthera humilis Engelm. & Gray, Best. 

 Journ. Nat. Hist. 5: 230. Name only. 1845. 



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, oval, 

 lanceolate, or linear, i'-3'long, 2"-iS" wide; 

 flowers in loose slender-peduuclcd axillary 

 spikes, which become 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"-5" long; capsule about 6" 

 long. 



In wet soil, especially along streams, southern 

 Virginia to Florida, west to Arkansas and Texas. 

 ]une-Aug. 



4. DIAPEDIUM Konig; Konig & Sims, Ann. Bot. 2: 189. 1806. 

 [DiCLiPTER.\ 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 in- 

 florescence mostly cymose or spicate, the involucres subtending i flower or several. Calyx 

 4-5-cleft, the lobes linear or subulate. Corolla-tube slender, slightly enlarged above, the 

 limb conspicuously 2-lipped; upper lip erect, concave, interior in the bud, entire or 2-3-toothed; 

 lower lip spreading, entire or 3-toothed. Stamens 2; anther-sacs parallel, sometimes unequal, 

 separated by a narrow connective. Style filiform; ovules 2 in each cavity of the ovary. 

 Capsule flattened, ovate or suborbicular, sessile or stipitate, 2-4-seeded. Placentae separat- 

 ing elastically from the walls of the capsule. Seeds compressed, nearly orbicular. 



About 60 species, natives of warm and tropical regions. Besides the following, 4 others occur 

 in the southern and southwestern United States. 



