940 ASCLEPIADACEAE 



lowish or greenish yellow, fragrant: follicles very slender, 1-4 dm. long, 7 mm. wide, at- 

 tenuate at each end, hairy: seeds 5 mm. long: coma 2-2.5 cm. long. [P. pubescens Ell.] 

 In sandy soil, North Carolina to Florida. Spring to fall. 



4. ACERATES Ell. 



Perennial caulescent herbs. Leaves opposite, alternate or scattered. Pedicels sub- 

 tended by numerous involucral bracts. Flowers greenish or occasionally purplish tinged. 

 Calyx small : lobes 5, acute, usually biglandulose at the sinus. Corolla rotate : lobes 5, 

 small, retlexed in anthesis. Column very short, not always apparent, with commonly 

 5-10 small glands or processes alternating with tlie anther-wings. Hoods mostly attached 

 over the whole of the column, erect, equalling or shorter than the anthers, involute-con- 

 cave, and somewhat pitcher-shaped, often pendulous and saccate at the base, entire, emar- 

 ginate or 2-.3-lobed or toothed at the apex, the ventral margins spreading towards the base 

 into broad auricles or small infolded concealed lobes, either destitute of horns or crests or 

 these rarely rudimentary. Anther-wings angulate near or somewhat below the middle, 

 narrowed and rounded towards the base or rarely of the same width from the apex down- 

 wards, entire or notched. Follicles as Asclepias. Green Milkweed. 



Auricles of the hood, when jiresent concealed within. 



Hoods rounded, entire at the summit, much shorter than the anthers. 1. A. Floridana. 



Hoods entire, rounded or acutish at the summit, as high as the anthers. 2. A. viridiflora. 



Auricles of the hood conspicuously spreading. 



Hoods emarginate or truncate at the summit, crestless within. 3. ^4. auriculata. 



Hoods 3-lobed at the summit, with an internal crest-like midrib, terminating in 



the middle lobe. 4. A. angustifolia. 



1. Acerates Floridana ( Lam. ) A. S. Hitchcock. Plant minutely scrabo-pubescent, 

 becoming glabrate. Stems 3-8 dm. high or higher : leaf-blades linear to elongated linear- 

 lanceolate, 7-16 cm. long, 3-5 cm. wide : umbels 2 or 3-several, usually many-flowered : 

 pedicels 1-1.3 cm. long: corolla-lobes oblong, about 3 mm. long, dull purple without: 

 hoods purplish, oval, obtuse, slightly pendulous at the base, adnate at the base to the 

 upper part of the distinct column, rising to about the middle of the anthers : anther-wings 

 angled at the middle : follicles erect on recurved fruiting pedicels, fusiform, 7-10 cm. long, 

 minutely puberulent : seeds 7 mm. long : coma 3-4 cm. long. [A. loiu/ifolia Ell.] 



On prairies and in wet pine lands, Wisconsin and Ohio to Florida and Texas. Spring to fall. 



2. Acerates viridiflora (Raf. ) Eaton. Plant tomentose-puberulent, becoming gla- 

 brate. Stems 2-6 dm. high, often procumbent : leaves opposite or some of them scattered ; 

 blades short-petioled, 4-G cm. long, oval or oblong, obtuse and refuse or acutish, usually 

 mucronate, sometimes with undulate margins, becoming leathery : umbels globose, sessile 

 or nearly so, 2-5 or more, lateral, densely many-flowered : pedicels about 1 cm. long : 

 corolla-lobes oblong-lanceolate, about 5 mm. long : hoods inserted over the whole short 

 column, dull purplish or at least tinged with purple, erect, nearly equalling the anthers, 

 lanceolate-oblong, entire, except for a pair of small infolded and concealed auricles at the 

 base : accessory processes 5 : anther-wings salient above the middle, half-rhomboid, entire, 

 or possibly obscurely notched, tapering towards the base : poUinia 2-5 mm. long, attenu- 

 ated to the short caudicles : follicles 6-10 cm. long, erect on recurved pedicels, fusiform, 

 attenuate, glabrous or minutely puberulent: seeds 7 mm. long: coma 2.5-3 cm. long. 



In dry and sterile soil. New England to Saskatchewan, southward to Florida, Texas. New Mexico 

 and north Mexico. Summer.— .4. viridiflpra IvtMi Britton, with elongated lanceolate leaf-blades, and 

 anther-wings rather more abruptly tapering at the base, ranges from Hlinois and Nebraska to Virginia, 

 Georgia and Louisiana. Another"form, .4. viridiflora linearis A. Gray, with low stems, elongated, linear 

 leaf-blades, and often a solitary umbel, ranges from the Northwest Territory to Minnesota, Louisiana 

 and New Mexico. 



3. Acerates auriculata Engelm. Plant glabrous, glaucous. Stems 2-8 dm. high, 

 mostly solitary, sinuous above when old and rarely branched : leaves alternate-scattered, 

 sometimes crowded ; blades narrowly linear or filiform-linear, 5-14 cm. long, the scabrous 

 margins not always revolute, becoming leathery and often twisted with age : pedicels 1 cm. 

 long, slender : involucral bracts slender, minutely puberulent : umbels many-flowered, lat- 

 eral. 1 or 2, or sometimes 16 on the same stem : column very short : calyx-lobes minutely 

 puberulent : corolla-lobes greenish, tinged with dull purple on the outside, about 4 mm. 

 long: hoods yellowish, with often a purplish keel, erect, crenately truncate or emarginate 

 at the apex, the involute sides spreading at the base into broad, obscurely crenate auricles: 

 anther-wings narrow and of equal width, entire or notched and twisted at the middle, in- 

 curved over the anthers at the summit, the intermediate spaces marked by a vertical dark 



