302 ORDER 119. EMPETRACE^E. 



Stems short (6"- 20, spreading on moist grounds. Leaves reniform NOB. 1, 3 



Stems (3 16') growing in water. Fruit sessile. x Leaves of two kinds... Nos. 8, 4 



x Leaves all linear No. 5 



1 C. Austin!! Eng. Lvs. obovate, 12" ; fruit depressed, 4-lobed all around, its pedi- 



cel and stig. nearly as long, lobes narrowly winged. N. J. (Porter), N. Y., and W. 



2 C. peploides N. Lvs. elliptical, 1" ; fruit roundish, 4-lobed above, sessile^ its stig- 



mas twice as long, lobes not winged. Tenn. to La. (Hale). 12'. 



3 C. verna L. Floating Ivs. 3", rosulate, obovate, narrowed below, the submersed 



leave* 6", oblong-linear; fruit oval, emarginate, longer than its stigmas. Pools. 



4 <!. heteropli^lla Ph. Floating leaves spatnlate. attenuate below, 4 (>", the sub- 



mersed linear, 6 9"; fruit globons, obcordate, its stigmas rather longer. Pools. 

 a C. an I u in Mali* L. Leaves all submersed, 35". linear, obtuse at both ends ; fruit 

 rounded, its lobes slighcly united, winged ; styles slender. Lakes and rivers. 



ORDER CXVII. PODOSTEMIACE^E. THREADFOOTS. 



Herbs aquatic, with the habit of seaweeds, with alternate, dissected 

 leave*, with flowers minute, perfect, naked or with 3 sepals. Stamens 1 or 

 many, hypogynous. Ovary compound, 2-3-celled, with as many stigmas, 

 and numerous ovules. Fruit a many-seeded capsule, ribbed and some- 

 what pedicelled. Albumen none. 



PODOSTEMUM, L. C. Rich. THHEADFOOT. RIVER WEED. Fls. 

 axillary, solitary. Sta. 2, fil. united below. Ovary oblong-ovoid. Stig. 2, 

 sessile, recurved. Caps. 2-celled. Seeds minute. Small, submersed ?, 

 adhering to stones and pebbles. 



P. ceratophyllum MX. Leaves alternate, repeatedly forking into linear, thread- 

 form segments ; stem a few inches long, in running water : common. 



ORDER CXVIII. CERATOPHYLLACE^E. HORNWORTS. 



Herbs aquatic, with whorled, dichotomously dissected leaves. Flowers 

 8 , sessile, axillary, minute, with neither calyx nor corolla. Involucre 8- 

 12-cleft. Anthers (12 24) sessile. Fertile flower a simple 1-celled ovary 

 with one ovule. Cotyledons 4. 



CERATOPHYLLUM, L. HORNWORT. Character that of the order, z? 



O. dcmcraum L. Stem floating or prostrate, 816', with numerous branches and 

 whorls ; leaf-segment filiform, sharply toothed. Pools. 



ORDER CXIX. EMPETRACE^E. CROWBERRIES. 



Heath-like shrubs, with evergreen, linear, exstipulate leaves, and small, 

 imperfect flowers. Calyx of 4 6 hypogynous, imbricated scales, the inner 

 often colored and petal-like. Stamens 2 4, with compound pollen. Ovary 

 free, 2-9-celled, 2-9-ovuled. Fruit fleshy, with as many seeds. In Balis 

 the drupes are consolidated. 



Stamen:) 3. Stigmas 6-9-rayed. Berry 6-9-seeded EMPKTKUM. 1 



Stamens 3. Stigmas 3 or 4. Style slender. Drupe 3- or 4-geeded OORKMA. . 3 



Stamens 2. Stiginas 4. Berry 2-seeded, Shrub erect CERATIOLA. 5 



Stamens 4 Stigma 1 Berry 4-seeded. Prostrate . .B.ms. t 



