APOCYNACEAE 935 
Longer calyx-lobes about 2 mm. long: corolla-tube 9-11 mm. long: stem and 
branches glabrous. 5. A. Texana. 
Longer calyx-lobes about 1 mm. long: corolla-tube 6-8 mm. long: stem and 
branches pubescent. 6. A. ciliata. 
1. Amsonia Ludoviciàna Vail. Stems 5-11 dm. tall, sparingly branched, pubescent, 
at least when young: leaves few; blades broadly elliptic to oval-elliptic, 6-9 cm. long, 
acute or acuminate at both ends, essentially glabrous above, densely white-tomentose 
beneath, the short petiole pubescent: calyx-lobes triangular or triangular-lanceolate, barely 
1 mm. long: corolla bluish ; tube 6-7 mm. long, pubescent about the base of the limb; 
lobes lanceolate, slightly shorter than the tube: follicles 8-10 cm. long, pubescent, at least 
the upper portion manifestly hairy. 
In moist or shaded grounds, southern Louisiana. Spring. 
2. Amsonia Amsónia (L.) Britton. Stems 6-13 dm. tall, more or less branched 
above, glabrous or sometimes with scattered hairs on the upper parts: leaves relatively 
few ; blades relatively broad, oval to broadly oblong-lanceolate, acute or acuminate, dull 
above, green and sometimes thinly pubescent beneath, thin-margined and ciliolate at 
maturity : calyx-lobes triangular, barely 1 mm. long : corolla purplish blue; tube 6-8 mm. 
long, pubescent about the base of the limb ; lobes linear to linear-lanceolate, shorter than 
the tube: follicles 9-12 em. long, glabrous, green. 
On river banks or in moist woods, New Jersey to Kansas, Florida and Texas. Spring and summer. 
3. Amsonia salicifolia Pursh. Similar to the next preceding species in size and 
habit : leaves relatively few ; blades relatively narrow, lanceolate to linear-lanceolate, 7-16 
em. long, acuminate, more or less lustrous above, glaucous beneath, callous-margined, not 
ciliolate : corolla purplish blue; lobes as long as the tube or longer: follicles 8-12 cm. 
long, glabrous, glaucous. 
In low grounds or thickets, Missouri to Tennessee, Alabama and Texas. Spring and summer. 
4. Amsonia rígida Shuttlw. Stems 8-13 dm. tall, regularly branched above, glabrous, 
more or less glaucous: leaves very numerous; blades elliptic or rarely oblong-ovate, 
2.5-6 cm. long, acute at each end or slightly acuminate at the apex, glabrous, deep green 
above, glaucescent beneath, short-petioled : calyx-lobes triangular or triangular-lanceo- 
late, about 1 mm. long: corolla purple-blue ; tube 4-6 mm. long, glabrous; lobes lanceo- 
late or oblong-lanceolate, as long as the tube or longer: follicles 7-12 cm. long, glabrous. 
In moist pine lands, Georgia and Florida. Spring and summer. 
5. Amsonia Texàna (A. Gray) Heller. Stems 1.5-7 dm. tall, often sparingly 
branched, glabrous: leaves numerous; blades oblong to narrowly elliptic or linear, con- 
spicuously narrower on the upper part of the plant, 2.5-6 cm. long, acute or blunt, often 
somewhat lustrous above, glabrous at least at maturity : calyx-lobes acuminate, the longer 
about 2 mm. long : corolla glabrous ; tube 9-11 mm. long ; lobes usually about as long as 
the tube : follicles 6-10 em. long, glabrous. 
In rocky soil, Texas. Spring and early summer. 
6. Amsonia ciliata Walt. Similar to the next preceding species in habit, but taller 
and more widely branched, the stem and branches pubescent: leaves numerous; blades 
linear, or filiform-linear on the upper part of the plant, broader below, pubescent or 
glabrous in age : calyx-lobes acute, the larger about 1 mm. long: corolla glabrous ; tube 
6-8 mm. long, as long as the tube or slightly shorter : follicles 8-16 cm. long, glabrous. 
Indry soil or pine lands, North Carolina and Arkansas to Floridaand Texas. Spring and summer. 
4. VÍNCA L. 
Perennial herbs, with creeping or trailing stems. Leaves opposite : blades thickish, 
entire. Flowers mostly solitary in the axils. Calyx-lobes 5, acuminate. Corolla funnel- 
form : tube terete, pubescent within: lobes broad, oblique. Stamens included : anther 
with a foliaceous connective. Disk of 2 glands alternating with the carpels. Carpels 2, 
united by the slender styles. Stigma glabrous. Ovules 6-8 in each carpel. Follicles 2 
together, few-seeded. Seeds slightly elongated, truncate at each end. PERIWINKLE. 
1. Vinca minor L. Stems 2-7 dm. long, branched: leaf-blades thick, ovate to 
oblong, 1.5-4 cm. long, blunt, lustrous on both sides but paler beneath, short-petioled : 
calyx-lobes lanceolate or subulate-lanceolate, 3-3.5 mm. long, glabrous: corolla blue; 
tube funnelform, about 1 cm. long ; lobes as long as the tube or nearly so, almost truncate. 
On roadsides and about gardens, Ontario to Georgia. Naturalized from Europe. Spring and summer. 
5. AMMOCÁLLIS Small. 
Shrubby plants, with erect stems, Leaves opposite: blades flat, entire. Flowers 
axillary, often 2 together. Calyx-lobes 5, slender. Corolla salverform: tube narrow, 
