RUE FAMILY RUTACEAE 
NORTHERN PRICKLY ASH. TOOTHACHE TREE 
Zanthoxylum americanum Mill. 
The Rue family is important because to it belong the 
citrus fruits, including the Orange, Lemon, Grapefruit, 
Lime and Tangerine. 
Q yy, 
The Prickly Ash or Toothache Tree is a shrub that grows 
s-10 feet tall. It occurs throughout the eastern part of the 
United States except in the extreme south. In Illinois it is 
found on floodplains, banks of streams and in moist woods, 
where it frequently forms dense thickets. The bark and fruit 
were formerly much used in medicine. 
The branches are always armed with prickles in pairs at 
the bases of the leaves and sometimes on the petioles as well. 
The dioecious flowers appear in April and May. Both forms 
are greenish white and relatively inconspicuous. The calyx is 
missing or obsolete, but there is a corolla of 4 or 5 petals. The 
pistillate flowers contain 2-5 separate pistils with slender styles. 
Stamens are as many as the petals and alternate with them. 
The reddish fruit, which matures in August and September, is a 
somewhat fleshy 1 or 2-seeded pod, strongly aromatic and ex- 
ceedingly bitter. The seeds are black and shining. 
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