pubescence or lack of pubescence on the corolla and calyx, that mainly separates 

 these entitites, is not an entirely reliable characteristic. 



3. Amsonia illustris Woods. Fig. 632. 



Stems erect, rather stout, from a woody rootstock, to 12 dm. tall; leaves 

 alternate, subcoriaceous to firmly membranaceous, rather narrowly lanceolate to 

 elliptic-lanceolate, to 1 dm. long and 3 cm. broad, acute to acuminate, cuneate at 

 the base, glabrous, the upper surface lustrous, the petioles 1-4 mm. long; inflores- 

 cence barely surpassing the foliage, bearing numerous pale-blue flowers; pedicels 

 2-8 mm. long; calyx lobes narrowly lanceolate, acuminate, 1.5-3 mm. long, more 

 or less pilosulous; corolla more or less pilose externally, the tube 6-8 mm. long, 

 about 1 mm. in diameter at the base, slightly dilated at the insertion of the 

 stamens, not constricted at the orifice, the lanceolate lobes 5-10 mm. long, 

 spreading; follicles somewhat articulate to essentially continuous, slender, papyra- 

 ceous, 8-14 cm. long, glabrous. 



In wet soil of swamps, coastal prairies, meadows, low woodlands, in mud about 

 lakes and in streams and ditches in the e. third of Tex. and s.e. Okla. (McCurtain 

 Co.), Mar.-June; from s. Mo. and e. Kan. to Tex. 



2. Trachelospermum Lem. Climbing Dogbane 

 About 30 species, all but the following in the Eastern Hemisphere. 



1. Trachelospermum diffoime (Walt.) Gray. Fig. 633. 



Herbaceous twining plant, glabrous to variously puberulent; leaves opposite, 

 with petioles to 12 mm. long, extremely variable and not infrequently hetero- 

 phyllous on a single plant, thinly membranaceous, elliptic to obovate-elliptic, 

 occasionally linear-elliptic or suborbicular, to 12 cm. long and 75 mm. broad, 

 acuminate at apex (occasionally very shortly and abruptly so), cuneate to rounded 

 at the base; flowers numerous, small, in alternate-axillary thyrsiform inflores- 

 cences; pedicels 4-7 mm. long; calyx 5-parted nearly to the receptacle; calyx 

 lobes ovate-lanceolate, acuminate, 3-4 mm. long, minutely and rather sparsely 

 barbellate at the tips, bearing within alternate pairs of squamellae; corolla pale- 

 yellow, salverform or subinfundibuliform, the tube 5.5-6.5 mm. long, about 

 1 mm. in diameter at the base, somewhat inflated at the orifice, the 5 lobes 

 obliquely obovate, 3-4 mm. long, dextrorsely contorted, spreading; anthers con- 

 nivent and agglutinated to the stigma, with an enlarged narrowly 2-lobed connec- 

 tive; ovary apocarpous, containing numerous ovules, surrounded at the base by 5 

 separate or more or less concrescent nectaries; stigma fusiform, borne upon an 

 elongate style; follicles 2, slender, terete, obscurely undulate-articulate to essen- 

 tially continuous, 15-23 cm. long, glabrous; seeds many, truncate, comose. 



Climbing on trees and shrubs along streams, in swamps and low ground, about 

 ponds, and on the edge of forests and in weedy areas in e. Tex. and s.e. Okla. 

 (Waterfall), Apr.-June; from Del. s. to Fla. and Tex., w. to 111., Ind., Mo. and 

 Okla. 



3. Apocynum L. Dogbane. Indian Hemp 



Herbaceous perennials, reproducing freely by horizontal gemmiferous roots, 

 with branching stems; leaves opposite or rarely verticillate, not glandular, often 

 mucronate-pointed; flowers small and pale, on short pedicels in terminal and 

 axillary cymes; calyx 5-parted nearly to the receptacle, without internal squa- 

 mellae, the lobes equal, scarcely imbricate; corolla campanulate to urceolate or 

 cylindric, the tube short, the limb regularly 5-parted, with small sagittate append- 

 ages at the base opposite the lobes, dextrorsely contorted; stamens on the very 

 base of corolla; anthers connivent and agglutinated to the stigma, with an enlarged 



1334 



