THE GENUS CBANOTHUS L. IN IOWA 
B. SHIMEK 
The low shrubs known as New Jersey Tea, belonging to the 
Genus Ceanothus, were once very abundant throughout Iowa, , 0 C“ 
curring chiefly on the prairies, and sometimes in dry, open woods 
and along the borders of drier thickets. On account of their long, 
tough roots they interfered with the breaking of the prairie, and 
the commoner species, C. americanus, known as “shoestring” or 
“red-root,” was by no means popular . with the pioneers. Per- 
haps for this reason, and because they were so common, these 
attractive shrubs were seldom cultivated in this state. 
In more recent years, however, as the native plants became 
rarer, their cultivation has increased, especially eastward. Their 
conspicuous dense clusters of small white flowers and their not 
unattractive foliage, together with their hardiness, make them 
very desirable for this purpose. As the forms in our state are 
very variable, and also differ somewhat in habit and distribution, 
a discussion of them should interest both the amateur lover and 
the scientific student of plants. 
The Genus Ceanothus, as now recognized, is wholly American. 
Related species from other parts of the world are now placed in 
other genera. In 1753 Linne recognized but three species, of 
which only one, our C. americanus, is now retained in the genus. 
The same species were listed by Aiton^ in 1789, but in 1811 he^. 
increased the number to five, of which three are now placed in 
other genera. In 1825 DeCandolle^® recognized forty-one species, 
but he included a dozen species now placed elsewhere. In 1867 
Bentham and Hooker® placed the number of species at about 
twenty-eight; Parry®^ listed thirty-three North American species 
in 1889; in 1896 Engler and PrantU® credited North America 
with thirty-six species ; while in 1905 Britton^^ placed the number 
at about thirty-five for North America. Up to 1913 the Kew 
Index and Supplements®^ enumerated sixty-eight species, which 
probably are not all valid. 
The great majority of the species are found in the dry sections 
* The superior figures throughout refer to the numbers in the Bibliography at the 
close of this paper. 
