ASCLEPIADACEAE 151 



ecliiuate. — On wet prairies especially in the valleys of the Big and Little 

 Blue and Fire Prairie Creek. Abundant locally. June- July. 



5. A. amplexlcaulis J. E. Smith. l°-22° high, glabrous: leaves ovate- 

 orbicular, clasping : umbel usually solitary : follicles glabrous, erect on 

 the decurved fruiting pedicels. — Locally frequent on dry prairies and 

 banks near Waldo Park, Lee's Summit, Grand View, Lake City and 

 Buckner May-June. 



6. A. Syriaca L. Common Milkweed. 2°-5° high, finely pubes- 

 cent : leaves oval-oblong, short-petioled, pubescent : umbels several : 

 follicles erect on the decurved fruiting pedicels, densely tomentose and 

 echinate. — Abundant throughout in fields and waste places. July-Sep- 

 tember. 



7. A. verticillata L. White Milkweed. 1°-3° high, pubescent : 

 leaves long-linear, numerous : flowers white : glabrous follicles and fruit- 

 ing pedicels erect. — Not uncommon in dry fields and prairies throughout. 

 June-July. 



2. ASCLEPIODORA A. Gray. 



Resembles Asclejyias, but corolla lobes spreading. Hoods hornless, 

 crested within. 



1. A. viridis ( Walt. ) A. Gray. Green Milkweed. 1°-2° high, gla- 

 brous : leaves opposite or alternate, ovate-oblong, short petioled, raucro- 

 nate : flowers 1^ broad, greenish with a purplish hood. — Kare and local in 

 dry soil near Pixley's, Lee's Summit, Grain Valley and Grand View. 

 June. 



3. ACERATES Ell. Milkweed. 



Differs from Asdepias in the hornless hools. 



Flowers white. 1. A. angustifolia. 

 Flowers greenish. 



Crown sessile. 2. A. viridifloro. 



Crown on a short column. 3. A. Floridana. 



1. A. angustifolia (Nutt. ) Dec. Prairie Milkweed. 1°-2° high, 

 slightly puberuient : leaves elongated-linear : umbels axillary, short- 

 peduncled or sessile : hoods three toothed at the apex. — Locally frequent 

 on rocky prairies near Waldo Park, Grand View and Lee's Summit. 

 June-July. 



2. A. viridiflora (Raf. ) Eaton. Green Milkweed. 1°-3° high, 

 downy to glabrate : leaves oval or oblong-ovate : umbels sessile or short- 

 peduncled : hoods aboiit equalling the anthers : hoods entire. — Rather 

 rare in dry rocky places near Waldo Park and Lee's Summit. June- 

 August. 



Var. Ivesii Britton. Leaves oblong-lanceolate. — Dry places through- 

 out especially in the southern part, but not abundant. 



Var. linearis A. Gray. Leaves linear. — Prairies near Buckner. 



3. A. Floridana (Lam.) Hitchcock. l°-3° high, glabrate to hairy : 

 leaves linear-lanceolate : umbels peduncled : hoods much shorter than 



