68 ARTIFICIAL KEY TO FAMILIES 
5. Small green disks floating on the surface of water, usually with 
thread-like roots extending downward in the water 
<i te eR te AREA Ofc LEMNACEAE. Pg. 93 
5) Plants with true leaves and stem, “9 esse = +) = = eee 
6. Flowers without white or colored perianth, arranged along a 
fleshy, club-like fae or in few flowered umbels. (11, 
U2) ioe a . . NAtADACEAE. Pg. 94 
6. Flowers with w vhite or colored perianth — Le Oe eee 
14. 
7. Perianth adherent to the surface of the ovary. (15, 16) 
Ay VALLISNERIACEAE, Pg. 108 
7. Perianth not adherent to the ovary, flowers subtended by a 
small leaf-like sheath, one or few in heads abs : 
Heteranthera in PONTEDERIACEAE. Roe 
SF eriagth of-bristiles; hairs: or scales ¢ 7. .° esa, 5 ° = ese ee 
8. Flowers with minute perianth or none . . tie 
8. Perianth of well-developed and conspicuous parts tPA © ice 
9. Perianth of bristles or hairs, flowers in compact cylinders. 
AT) was. * es 0 eens) ee eee ee PHA CRA Rae ce Oma ee 
Beeeantih wok racaias: oY ues eh tS ee eee ec 
10. Perianth of one or more very small scales, flowers in dense 
Betass) CTS) 19s. : - «© . NSPARGANIACEAE, (Po. °92 
10. Perianth of 6 husk- like scales, green or brown, rush-like 
plants. (22) ek wee Coe eee. JUNCACEAE. Pg. 118 
20. 
11. Flowers without perianth, on a fleshy spike (spadix), usually 
surrounded by or subtended by a leaf-like bract. (21) 
ETO bare A on BP tee ARACEAE. Pg. 109 
11. Plants with rush-like cylindric leaves and flower stems. 
Flowers in slender spikes, perianth herbaceous. (19) 
- . TRIGLOCHINEAE, Pg. 102 
