ANATOMY OF SOME PLANTS OF A PROVINCE IN IOWA 
8l 
Parenchyma: 
Subcentric leaves. 
(1) Five layers palisade parenchyma. 
(2) Four layers palisade. 
Centric. 
(1) Three upper, two lower layers palisade ; spongy parenchyma 
loose. 
(2) Three upper, two lower layers palisade; spongy parenchyma 
large-celled, compact. 
(3) One upper, one lower layer palisade; spongy parenchyma 
large-celled, compact. 
(4) One upper, one lower layer palisade; spongy parenchyma 
horizontally elongated. 
Bifacial. 
(1) Two layers of palisade cells; spongy parenchyma cells 
compact, small. 
(2) Two layers of palisade cells; spongy parenchyma cells 
large, compact. 
(3) Three layers of palisade cells; spongy parenchyma cells 
loose, elongated. 
(4) Four layers of palisade cells; spongy parenchyma cells 
loose, elongated. 
Radial palisade. 
(1) Radial palisade; spongy parenchyma homogeneous. 
(2) Radial palisade; spongy parenchyma homogeneous. 
II. Alluvial basin: Leersia oryzoides, Muhlenbergia mexicana, Polyg- 
onum Muhlenbergii, Baptisia leucantha, Steironema lanceolata, Asclepias 
verticillata, Apocynum cannabinum, Mimulus ringens, Lycopus virginicus, 
Mentha canadensis, Physostegia virginiana, Solidago serotina, Solidago 
graminifolia, Vernonia noveboracensis, Silphium laciniatum, Aster salicif alius. 
Epidermis: Of the sixteen alluvial basin plants examined, nine have a 
lower epidermal wall relatively thinner than that on the upper side. Ten 
are smooth. 
Parenchyma: 
Subcentric. 
(1) Five layers palisade. 
(2) Six layers palisade. 
(3) Seven layers palisade. 
Centric. 
(1) One upper, two lower layers palisade; spongy parenchyma 
compact. 
(2) Two upper, two lower layers palisade; spongy parenchyma 
compact. 
