120 BOTANY 
zestivation; tube sometimes with scales, alternate with the lobes of the | 
limb. Stamens five, inserted in the base of the corolla, and alternate with 
its lobes. Disk annular, hypogynous. Ovary free, two- to four-celled, rare- 
ly by abortion one-celled; ovules definite, erect, when more than one, col- 
lateral ; style one, usually bifid, rarely two; stigmas obtuse or acute. Fruit 
succulent or capsular, one- to four-celled, with septifragal and septicidal, or 
circumscissile dehiscence. Seeds albuminous; embryo curved or spiral; 
cotyledons corrugated or inconspicuous ; radicle inferior. Herbs or shrubs, 
usually twining, sometimes parasitical, often with a milky juice, and with 
alternate, sided or lobed, exstipulate leaves, rarely leafless. They occur 
chiefly in tropical and temperate regions. ‘The order has been divided into 
two sub-orders. 
Sub-order 1. Convolvulee, true Bindweeds, leafy plants with the corolline 
tube not scaly, embryo curved, cotyledons conspicuous. 
Sub-order 2. Ciecie| Doddees. leafless parasites, having scales on the 
corolline tube, embryo spiral and filiform, cotyledons inconspicuous. There 
are forty-five genera and upwards of T00 species. Examples: Calystegia, Con- 
volvulus, Ipomoea, Exogonium, Dichondra, Cuscuta. | 
This order contains plants of considerable economical importance. Jalap is 
obtained from Exogonium purga (Convolvulus jalapa) a native of Mexico ; 
Conyolvulus scammonia yields scammony. The root of Batatas edulis (Con- 
volvulus batatas) is known as the sweet potatoe. 
Kxogonium purga, Jalap plant, Mexico (pl. 63, fig. T); a, pistil ; 6, capsule ; 
c, a seed. 
Orper 92. HypropHyLuaces#, the Water-leaf Family. Herbs, commonly 
hairy, with mostly alternate and cut-lobed leaves, regular five-merous, and five- 
androus flowers, as in the Borage Family, but the ovary ovoid and entire, one- 
celled, with two parietal few- or many-ovuled placentas, which usually project 
into the cell, and often line it like an interior pod. Style two-cleft above. 
Pod globular, two-valved, few-seeded. Seeds reticulated or pitted, amphitro- 
pous, with a minute embryo in cartilaginous albumen. Flowers chiefly blue or 
white, in one-sided cymes or racemes, which are coiled from the apex when 
young; pedicels bractless. Examples: Hydrophyllum, Phacelia, Eutoca. 
All North American. 
OrperR 93. Diapenstacez, Mountain-box Family. Dwarf and_ tufted, 
somewhat shrubby plants (only two in number), with small and evergreen 
heath-like foliage, the fruit agreeing with Polemoniacex. as do the flowers, 
except in the following points, viz. Calyx of five separate and strongly 
imbricated persistent sepals, like the bracts. Stamens five, inserted in the 
very sinuses of the bell-shaped corolla; filaments short and flat; anthers 
opening transversely across the cells on the inside. Style single, stigma 
minutely three-lobed. Kxamples: Diapensia and Pyxidanthera, both low, 
evergreen shrubs. Diapensia lapponica is found in the Alpine summits of 
Mounts Washington, and Marcy or Tahawus. 
Orver 94. PoLEmMoniAce #, the Phlox Family. Calyx inferior, five-divided, 
persistent, sometimes irregular. Corolla regular, rarely irregular, five-lobed. 
Stamens five, inserted on the middle of the tube of the corolla, and alternate 
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