250 MAYACACEAE 
convex above: seeds On 16-ribbed.—Pools, various provinces, Fla. and 
Ga. to Calif. and Wyo 
4. L. diac Eu Root-sheath acute: plant-body obovate, usually ob- 
liquely s . long, obtuse, often papillose along the midrib and with 
a larger prend papilla: utriele tipped with the eecentrie style. "ud nds and 
Egan streams, various provinces, Fla. to Kans., N. D., and Mas 
5. L. trinervis (Austin) Small. Root-sheath with lateral appendages: plant 
body PORE or ape so, a little convex abov e, flat beneath, abruptly narrowed 
to the blunt apex, smooth: utricle tipped with the terminal style.—Stil water, 
various hae a a to Kans. and N. J. 
6. L. cyclostasa Y rua Root- s without appendages: duod peu 
oblong or nearly so, 2.8—4.5 mm. long, obtuse, often somewhat faleate, 
metrieal at the m d D l-nerv ed. [L. valdiviana Philip pi] Pools, 
various provinces, Fla. to Tex., Calif., and Mass.—(Mez., S. A.) 
4, SPIRODELA Schleid. Plant- body disk-like, conspicuously several- 
nerved. Anther- -sacs opening lengthwise. Utricle lenticular, with winged mar- 
gins.—Three species, 2 in America, the other 
in S Asia and Australia. 
1. S. polyrhiza (L.) gn Plants mori RENN O 
sterile and perennial: ro pla DA 
body obovate or suborbieular, J a 8 mm. Sfp WN: 
long, 5—15-nerved: seeds e oth.— —(Dvox- EH n a 
Minwow-FOLE.)—Poo s, ponds, and QD TR 
one streams, various cae Fla. to a 
ur. E. B. 2 Ont., and N. S— y 
C. A., S. Bee W.)— \ | i 
hue to the E of pools. They are often 
— (Mer 
— Sum. —Floating dense 
xad ^ plan s give à pale golden-green 
purple beneath. 
OrpER XYRIDALES — XYRIDAL ORDER 
Caulescent moss-like or acaulescent rush-like terrestrial herbs. Leaves 
alternate, equitant when basal: blades narrow, sometimes notched at the 
apex. Flowers axillary or usually borne in a terminal cone-like spike. 
Calyx regular or one sepal crested. Corolla regular. Gynoecium with a 
superior ovary. Fruit a capsule. Seeds minute, often caudate. 
Caulescent moss-like herbs: flowers axillary to leaf-like bracts: oS alike: styles 
wholly united. Fam, 1. MAYACACEAE. 
Acaule Ern rush-like herbs: flowers in terminal dense spikes 
e 
nited. 
2 forms, or 1 sepal wanting: styles epe 
Fam. 2. XYRIDACEAE. 
Faminy d. MAYACACEAE — Boa-woss FAMILY 
Leaves eauline: blades narrow, flaccid, l-nerved, minutely notched at 
the apex. Flowers perfect, borne on axillary pedicels. Sepals 3, nar- 
