
AQUATIC PLANTS OF FRESHWATER 

cavity. It is half-hardy plant introduced from Chili, of most delicate 
vivid green foliage composed of finely cut leaves. Flowers in July 
and August. 
Proserpinaca pectinata (Lamm.) and P. pectinacea (T. and G.) or 
Cut-leaved Mermaid-weed may be found in sandy swamps near the coast 
from Massachusetts to Florida and west of Louisiana. Flowers June to 
September. Somewhat similar to the above. As will be seen by the 
illustration, these plants differ in appearance with Parrot’s feather, the so- 
called Proserpinaca of the aquarium. They are tender-leaved plants and 
do not usually survive in household aquaria. 
LUDWIGIA 
Of the so-called Swamp Loosestrife, named for the German naturalist 
Ludwig, there are about 25 aquatic or semi-aquatic species native to warm 
and temperate regions and abundant in the United States and North 
America; the most generally distributed being the 
following, of which the popular names indicate 
the character; and also several introduced species 
extensively cultivated for the aquarium. They 
are beautiful foliage plants of most attractive 
colorings. Those most generally to be obtained 
are:—Isnardia palustris or Ludwigia palustris, 
Marsh purslain or False Loosestrife; L. polycarpa, 
Many-leaved Ludwigia; L. spherocarpa, Globe- 
fruited Ludwigia; L. glandulosa, Cylindric-fruited 
Ludwigia; L. /inearis, Linear-leaved Ludwigia; 
L. alternefolia, Alternate-leaved Ludwigia; L. 
Airtella, Hairy Ludwigia; L. alta, Wing-stemmed 
Ludwigia, and several Ludwigianthas and Isnar- 
dias, kindred species of similar habit and character; 
all fairly good oxygenators for aquarium and 
aqua-terrarium culture. 
Ludwigia palustris (Linn.) or Marsh Purslain, 
Fig. 118,is a recumbent or floating aquatic, rooting 
in the mud of ditches and swamps, having opposite 
spatulate leaves, acute at the apex and narrowed 
into a slender petiole or stem; with axillary 

FIG. 118. Marsh Purslain, 
Ludwigia palustris: Reduced one- 
aoc flowers having bractlets at the base of the calyx, . 
triangular lobes and reddish petals. The branching and erect stems are 
of purplish-red color and the submerged leaves a golden-red and pale- 
green, and the emersed leaves a lustrous dark-green, all having distinct 
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