204 



ACANTHACEAE. 



[Vol. III. 



I. Dianthera Americana L,. 



Dense -flowered Water Willow. 



(Fig. 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"- 

 8 /r wide, entire, narrowed at the base into 

 short petioles, or sessile; flowers violet, or 

 nearly white, capitate-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 v long, its tube shorter than the lips, 

 the base of the lower lip rough and palate- 

 like; capsule 6 V 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. Doose-nowered Water Willow. (Fig. 3375.) 



Dianthera ovata Walt. Fl. Car. 6$. 1788. 



Dianthera humilis Engelm. & Gray, Bost. 

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



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, oval, 

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

 flowers in loose slender-peduncled axillary 

 spikes, which become V-if 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 7/ 

 long. 



In wet soil, especially along streams, southern 

 Virginia to Florida, west to Arkansas and Texas. 

 June-Aug. 



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

 [DicupTERA Juss. Ann. Mus. Paris, 9: 267. 1807. J 

 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 1 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. 



