584 PODOSTEMACEAE 
se and petals numerous: 
leaves opposite. Fam. 13. CALYCANTHACEAE. 
ies united, enclosed by the hy- 
anthium and adnate to it: fruit 
me Fam. 14. MALACEAE. 
Carpel ‘solitary, not becoming an achene. 
Ovary with 2 ee leaf-blades 
SIE: fruit drupe. Fam. 15. AMYGDALACEAE. 
Ovary with a ovules : aL 
E a 2-3-pinnate : fruit 
legum 
Petals B A in the bud. Fam. 16. MIMOSACEAE. 
als imbricated in the bud : 
leditsia and Ggymmnociadus in Fam. 17. CASSIACEAE. 
arly o i egular 
in leditsia an Gymnocladus in 
CASSIACEAE). 
Fruit ee armed with barbed 
a dE leaf-blades simple: stipules 
Fam.18. KRAMERIACEAE. 
Fruit E "I eme or loment: leaf-blades 
mpound: stipules usually pres- 
Upper petal enclosed by the lateral 
ones in the bud. Fam. 17. CASSIACEAE. 
Upper petal enclosing the lateral 
ones in the bud. Fam. 19. FABACEAE. 
FamiIty 1. PODOSTEMACEHAE—RIvER-WEED FAMILY 
Aquatic herbs, adhering to rocks, the vegetative organs resembling 
the thallus of an alga or a hepatic. Leaves alternate: blades lobed or 
decompound. Flowers ae arising from a spathe. Perianth wanting, . 
or of 3-5 scale-like or membranous sepals. Androecium of 1—man 
stamens. Gynoecium of 2 or 3 united carpels. Fruit capsular—About 21 
genera and 175 species, mostly natives of the tropies. 
1. PODOSTEMON Michx. Caulescent alga-like herbs. Leaf-blades di- 
vided or dissected. Flowers green.  Perianth obsolete. Stamens 2. Ovary 
2-celled. Capsule unequally 2-valved, one valve persistent.—About 12 species 
of wide geographical distribution —Sum.—fall.—RIvER-WEED. 
Flower solitary: leaf-segments flatten ed. 1. P. ee 
Flowers 2 or 3 together: leaf-segments almost capillary. 2. P. otanoides. 
1. P. Ceratophyllum Michx. Plant olive-green, glabrous. Stems 0.5-2 dm. 
long, attached to stones in running water by disk-like expansions: fe rigid ; 
bl i 
ades divided into many nar segments, 
the base sheathing the : flower 
tary, slender-pedicelled: fila 
much longer than vary: capsule oval 
— READ-FOOT. J 
5 mm. long.—(TH F P 
GREEN.)—-Attached to rocks in streams, vari- 
ous provinces N of Coastal Plain, Ga. to 
Ala., Ont., and N. B. 
2. P. _abrotanoides Nutt. Similar to 
. — Streams, 
Coastal 5 een extending into adj. provinees, 
W Fla. o Miss., Tenn., and C Ga. 
