SUPPLEMENT. 
THE FAMILIES OF FLOWERING PLANTS 
By Cuarzes Louis Poitarp. 
CHAPTER XXII.—Continued. 
Family Trigoniaceae. Trigonia Family. A small group of South 
American trees consisting of two genera, Trigonia, with 26 species, and 
Lightia, with two. The plants are most anomalous in structure, and 
have given botanists much trouble to dispose of them properly in the 
systematic sequence. The flowers are very irregular, one petal being 
much larger than the remaining four, and placed uppermost, like the 
banner petal in a papilionaceous flower. One of the petals is spurred 
somewhat like a violet; the stamens are united in two series. 
Family Vochisiaceae. Vochy Family. Contains 7 genera and 
about 180 species, exclusively South American. They are trees or 
shrubs with opposite leaves and very showy yellow, white, pink or pur- 
ple flowers in large terminal racemes or panicles. The flowers are 
irregular, having 4 to 5 sepals, an equal number of petals, and few sta- 
mens, sometimes reduced to one; the ovary is 3-celled, becoming a 
winged fruit or capsule. Vochisia and Qualea are often cultivated for 
their beautiful flowers, and the trees frequently yield valuable timber, 
the well-known copaiyé wood of Guiana being the product of Vochisia 
Guianensis. A yellow dye is also obtained from certain species of 
Qualea. The popular name which I have adopted for the family is de- 
rived from the native name of some of the trees in Guiana. 
Family Tremandraceae. Tremandra Family. Two genera, TJre- 
mandra and Platytheca, the former with two species, the latter with 
one, all confined to West Australia. They are heath-like shrubs with 
red, blue or white slender-pedicelled flowers; the latter are regular, 
with 4-5 sepals, 4-5 petals, 8-10 stamens, and a 2-celled ovary. 
Family Polygalaceae. Milkwort Family. These plants are herbs, 
rarely shrubs. or small trees, comprised in about 10 genera and 750 
species, widely distributed in both temperate and tropical regions. 
Polygala is the most important genus, consisting of over 250 species, a 
fifth of which are found in the United States. The plants are of inter- 
est to the botanist on account of the somewhat singular structure of 
