: ACANTHACEAE 1081 
39. SCHWALBEA L. 
Perennial caulescent herbs, finely pubescent and glandular. Leaves alternate : blades 
entire, 5-nerved, sessile. Flowers in terminal bracted racemes. Calyx of 5 well-united 
sepals: tube 10-12-ribbed, oblique: lobes shorter than the tube. Corolla yellowish 
purple, very irregular: upper lip arched, entire; lower lip shorter, 3-lobed, 2-plaited. 
Stamens 4, didynamous, ascending under the upper lip of the corolla: anthers, and the sacs, 
alike. Capsule narrow, loculicidal. Seeds numerous, with a loose reticulated testa. 
1. Schwalbea Americana L. Stems 3-8 dm. tall, simple or sparingly branched. 
Leaf-blades oblong, elliptic or ovate-elliptic, 1.5-3.5 em. long, acute, entire : flowers short- 
pedicelled : calyx thinly lanuginous, 1.5-2 em. long; upper and lateral lobes lanceolate, 
the upper 3 as long as the lateral; lower lobe oblong, with a V-shaped sinus at the apex : 
corolla 3-3.5 cm. long, pubescent without ; tube surpassing the calyx, longer than the lips: 
capsules oblong, 10-12 mm. long. 
In swamps or low grounds, Massachusetts to Florida and Louisiana. Spring and summer. 
FAMILY 14. ACANTHACEAE J. St. Hil. AcANTHUS FAMILY. 
Annual or perennial herbs, or shrubby plants pervaded by bitter, acrid or 
often emollient properties, otherwise of little economic value. Stems enlarged 
at the jointed nodes. Leaves alternate, opposite or rarely whorled, without 
stipules: blades simple. Flowers perfect, irregular, sometimes solitary,-often 
subtended by conspicuous bracts. Calyx of 5 nearly distinct or variously united 
sepals, sometimes subtended by bractlets. Corolla of 5 partially united petals, 
2-lipped or sometimes almost regularly 5-lobed ; lobes convolute or contorted. 
Androecium of four didynamous, or two equal stamens, the other pair abortive 
or obsolete. Filaments filiform or subulate. Anthers with 2 equal or unequal 
sacs. Gynoecium 2-carpellary. Ovary free, 2-celled with the placentae in the 
axis. Styles terminal, united. Stigmas entire or 2. Ovules often few, com- 
monly 2 in each cavity, sessile, amphitropous or campylotropous. Fruit a mem- 
branous, leathery or cartilaginous capsule, typically with 2 cavities, opening 
loculicidally and elastically. Seeds usually flattened, with a leathery, fibrous 
or loose, often tuberculate, sometimes pilose, testa. Embryo curved or rarely 
straight, with large cotyledons. 
Leaves normal only at the base of the stem, those on the stem reduced to firm sheathing imbricated 
scales and passing into the inflorescence. 1. TUBIFLORA. 
Leaves normal on the stem. 
Corolla convolute in the bud. 
Corolla conspicuously 2-lipped : capsule terete, not constricted at the base. 2. HYGROPHILA. 
Corolla barely if at all 2-lipped : capsule constricted into a stipe-like base. 
Calyx-lobes bristle-like: anther-sacs awned or pointed atthe base: ovules 
2 in each cavity. i 
Calyx-lobes linear or lanceolate: anther-sacs pointless: ovules 3-10 in 
3. CALOPHANES. 
. each cavity. 4. RUELLIA. 
Corolla imbricated in the bud. Bee 
Stamens 4 : anthers i-celled. 5, STENANDRIUM. 
Stamens 2: anthers 2-celled. : 
Placentae separating from the valves of the capsule. 
Flowers and their subtending bractlets covered by a large bract. 6. TETRAMERIUM. 
Flowers and their subtending bractlets not covered by a large bract. 7. DIAPEDIUM, 
Placentae persistently attached to the valves of the capsule. 
Anther-sacs equal, contiguous, parallel. 8. ANISACANTHUS. 
Anther-sacs unequal or unequally inserted, one lower than the other. 
Lower anther-sac with a spurred or mucronate base. 
Corolla-tube elongated, slender or filiform: anther-sacs unequally 
inserted, one lower than the other. i 9. SIPHONOGLOSSA. 
Corolla-tube very short: anther-sacs separated, oblique. 10. JUSTICIA. 
Both anther-sacs rounded. or rarely both mucronate at the base. 
Corolla with 4 nearly equal lobes: anther-sacs contiguous, un- 
equally inserted. P 
Corolla manifestly 2-lipped: anther-sacs separated on a dilated 
connective. 
Flowers on axillary peduncles: anther-sacs wholly separated, 
very oblique. : 3 : 
Flowers solitary in the axils of the leaves or in terminal bracted A 
spikes: anther-sacs approximate, slightly oblique. 13. CROFTIA. 
1. TUBIFLORA J. F. Gmel. 
Perennial caulescent herbs, with glabrous foliage. Stems sometimes scape-like. 
Leaves alternate or nearly opposite, basal or crowded at the ends of the branches: blades 
ll. YEATESIA. 
12. DIANTHERA. 
