20 



APOCYNACEAE. 



VOL. III. 



Flowers small, cymose. 



Erect or diffuse herbs ; corolla campanulate. 

 High-climbing vines ; corolla funnelform. 



3. Apocynum. 



4. Trachelospermum. 



i. AMSONIA Walt. Fl. Car. 98. 1788. 



Perennial herbs, with alternate membranous leaves, and rather large blue or bluish flowers, 

 in terminal thyrsoid or corymbose cymes. Calyx 5-parted, the segments narrow, acuminate. 

 Corolla mostly salverform, the tube cylindric, but somewhat dilated at the summit, villous 

 within. Stamens inserted on the throat of the corolla, included; anthers ovate or oblong. 

 Disk none. Ovary of 2 carpels, connected at the top by the filiform style; ovules in 2 rows 

 in each cavity, numerous; stigma appendaged by a reflexed membrane. Fruit of 2 cylindric 

 several-seeded follicles. Seeds cylindric or oblong, obliquely truncate at each end, not 

 appendaged. [Named for Charles Amson of South Carolina.] 



About 8 species, natives of North America and eastern Asia. Besides the following, 5 others 

 occur in the southern and southwestern United States. Type species: Amsonia Tabernaemontana 

 Walt. 



/sJXI Wfr/) * Am sonia Amsonia (L.) Britton. Am- 



yWKfaL sonia - ? 3374- 



Tabernaemontana Amsonia L. Sp. PI. Ed. 2, 308. 



1762. 



Amsonia Tabernaemontana Walt. Fl. Car. 98. 1788. 

 A. salicifolia Pursh, Fl. Am. Sept. 184. 1814. 

 A. Amsonia Britton, Mem. Torr. Club 5: 262. 1894. 



Glabrous or nearly so, simple, or branched 

 above, 2-4 high. Leaves ovate, ovate-lanceolate 

 or lanceolate, entire, acuminate at the apex, nar- 

 rowed at the base, sometimes pubescent beneath, 

 2'~4' long, i'-z' wide ; petioles 2"-4" long; flowers 

 numerous ; pedicels bracteolate at the base ; calyx 

 about i" long, its segments subulate ; corolla 

 6"-o/' long, beaked by the convolute limb in the 

 bud, its lobes linear and about as long as the 

 tube ; follicles 2'-4' long, about 2" thick, attenuate 

 at the apex, glabrous, divergent or ascending; 

 seeds papillose. 



In moist soil, New Jersey to Illinois, Kentucky. 

 Missouri, Florida and Texas. Consists of several 

 races, differing in leaf-form. April-July. 



"2 2 . VI'NCA L. Sp. PI. 209. 1753. 



Erect or trailing herbs, some species slightly woody, with opposite leaves, and large soli- 

 tary blue pink or white axillary flowers. Calyx 5-parted, the segments narrow, acuminate. 

 Corolla salverform, the tube cylindric, or expanded above, pubescent within, the lobes convo- 

 lute, at least in the bud, oblique. Stamens included. Disk of 2 glands, alternate with the 

 2 carpels. Ovules several in each carpel; style filiform; stigma annular, its apex penicillate. 

 Follicles 2, erect or spreading, cylindric, several-seeded. Seeds oblong-cylindric, truncate at 

 each end, not appendaged. [The Latin name.] 



About 12 species, natives of the Old World. Typ< 

 species : Vinca major L. 



i. Vinca minor L. Periwinkle. Myrtle. 

 Fig- 3375- 



Vinca minor L. Sp. PI. 209. 1753. 



Perennial, trailing, glabrous ; stems 6'-2 long. 

 Leaves oblong to ovate, entire, firm, green both 

 sides, obtuse or acutish at the apex, narrowed at 

 the base, short-petioled, \'-2.V long, i'-i' wide; 

 flowers not numerous, solitary in some of the 

 axils, blue, 9"-i5" broad ; peduncles slender, \'-\V 

 long; calyx very deeply parted, the segments subu- 

 late-lanceolate, glabrous, about ii' long; corolla- 

 tube expanded above, as long as or slightly longer 

 than the obovate, nearly truncate lobes ; anther- 

 sacs with a broad connective ; follicles few-seeded. 



Escaped from gardens to roadsides and woods, On- 

 tario to Connecticut, southern New York and Geor- 

 gia. Native of Europe. Leaves shining. Also called 

 running myrtle or small periwinkle. Feb.-May. 



