CALLITRICHACE2E. ( WATER-STARWORT FAMILY.) 403 
ends, often notched at the apex. (C. autumn&lis ? Michx.) — In clear 
water, N. New England, &c. — Leaves long, deli£hte and trans¬ 
lucent. 
Order 97. PODOSTEMACEiE. (River-weed Fam.) 
Aquatics, growing on stones in running water , with much 
the aspect of Sea-weeds or Mosses, with the minute naked 
flowers bursting from a spathe as in Liverworts, producing 
a 2-3 -celled many-seeded ribbed pod; — represented in 
North America by the genus 
1* PODOSTEIWUJM, Michx. River -weed. 
Flowers axillary and solitary, pedicelled, from a tubular spathe. 
Calyx, or bracts, of 2-3 small awl-shaped scales. Stamens 2 , 
or rarely 3 : filaments monadelphous below : anthers 2-celled. 
Styles or stigmas 2 , awl-shaped. Pod oval, many-ribbed, 2 -celled, 
2-valved. Seeds minute, very numerous on a thick persistent cen¬ 
tral placenta, destitute of albumen. — Leaves finely many-cleft, 
forking : stipules adherent to the partly sheathing base. (Name 
from 7 rovsjfoot, and or rjncov, stamen; the stamens being apparent¬ 
ly raised on a stalk by the side of the ovary.) 
1. P. ceratopliylliun, Michx. Leaves rigid; filaments unit¬ 
ed to above the middle. — Not uncommon in the bottom of shallow 
streams, flowering in July. A small olive-green plant, of firm or al¬ 
most horn-like texture, somewhat resembling a Sea-weed, and tena¬ 
ciously fixing itself to loose stones at the bottom, in the manner of a 
Fucus , by fleshy disks or processes in place of roots. Leaves several 
times forked, l'-4' long; the divisions linear-thread-form, flatfish. 
Order.98. EUPHORBIACEjE. (Spurge Family.) 
Plants usually with a milky acrid juice , and various , 
usually monoecious or dioecious flowers; the fruit of 2-3 
or several l-seeded pods united around a central axis sepa¬ 
rating when ripe (rarely of a single pod). Seed suspend¬ 
ed, anatropous. Embryo with flat cotyledons nearly as 
long as the albumen. Stigmas 2 - 3 or more, often forked. 
Calyx usually valvate in the bud, occasionally wanting. 
Petals sometimes present. 
