ee eT 
ih gt Reanil y kn. aeateei a aeS A e alte  eae 
bas? Sag ate © Ag ' 
42 MISSOURI BOTANICAL GARDEN. 
(Bigelow, 1867; Gillman, 1870; Campbell, 1886); Illinois (Hall, 1867; 
Eggert, 1891; Thompson, 1896); Kentucky (Barclay, 1895); Tennessee 
(Gattinger, 1882); Iowa (Hitchcock, 1888); Missouri (Engelmann, 1867; 
Bush, 1896; Thom  %n, no, 15, 1896); Louisiana (Riddell, 1867). 
EXPLANATION OF PLATES ILLUSTRATING LEMNACEAE. 
The figures are for the most part camera sketches of 
living material prepared at various times by the author. A 
few details are reproduced from Dr. Engelmann’s sketches. 
It has been the aim in each species to give only the 
distinguishing characters without going into the more 
minute structural details. In all species first is given a 
group of plants of natural size; a lateral view of the fronds 
on a water surface line, enlarged four diameters; a group 
of fronds enlarged five diameters, showing gross details ; 
the basal portion of a frond enlarged five diameters, show- 
ing the attachment of the stipe, and in the first two genera 
showing the bases of the roots with their appendages. Also 
in each of these genera is shown a rootcap enlarged twenty- 
five diameters; an inflorescence enlarged fifteen diameters, 
showing spathe, pistil and two stamens. In a few instances 
a pistil is again represented enlarged thirty diameters. 
The fruit when represented is enlarged fifteen diameters and 
the seed ten diameters. In Lemna minima the seed is 
again enlarged to thirty diameters. In the genus Wolfia 
the fronds are again represented in lateral and basal views 
enlarged fifteen diameters. 
Plate 1, A. Spirodela polyrrhiza, with details; B. Spirodela punctata, 
with details. 
Plate 2, A. Lemna gibba, with details; B. Lemna minor, with details; 
C. Lemna trisulca, with details. 
Plate 3, A. Lemna perpusilia, with details; B. Lemna perpusilia var. 
trinervis, with details; C. Lemna cyclostasa, with details; D. Lemna 
minima, with details, 
Plate 4, A. Wolfiella Floridana, with details; B. Wolfiella oblonga, 
with details; C. Woilfiella lingulata, with details; D. Wolfia papulifera, 
with details; E. Wolfia punctata, with details; F. Wolfia Columbiana, 
with details; G. Wolfia Brasiliensis, with details. 
22 
