146 FAMILIES OF FLOWERING PLANTS 
berries are pungent and aromatic, and are sometimes chewed as a rem- 
edy for toothache. The trees of the Brazilian genus Esenbeckia have 
bark possessing bitter and tonic properties. 
The orange and orange-like plants have frequently been classed as 
a distinct family, but are now usually included in the Rutaceae. There 
are numerous genera in this tribe, almost exclusively Hast Indian in 
origin, but frequently cultivated. All are distinguished by the familiar 
pulpy fruit. The orange, lemon, lime and shaddock all belong to the 
genus Citrus. Mention should be made of one other American ruta- 
ceous tree, the hop trefoil (Péelea), distinguished by its trifoliate leaves 
and dry, winged fruit. 
Family Simarubaceae. Ailanthus Family. Contains about 27 
genera and 150 species, natives of tropical regions. They are trees or 
shrubs with bitter bark, distinguished from the preceding family mainly 
by the absence of dots on the foliage. The flowers are regular, either 
perfect or dioecious, 3-5-parted, the petals 
borne on a disk. The fruit is various. 
Our only North American representa- 
tives of this family are the ailanthus or “tree- 
of-heaven,” a well-known shade tree exten- 
sively naturalized from Asia, and an indig- 
enous species of Simarouba, on the Keys of 
south Florida. Various South American 
species of the genus yield valuable medi- 
cines. Quassia is the product of several 
Fig. 128. Cross-section of flow- trees belonging to this family, but is princi- 
ers, enlarged. 1. Quassia (,Sima- ‘ i‘: A 
rouba officinalis). 2. Boswellia Car. Pally derived from Simarouba amara (Fig. 
teri, 3. Mahogany (Swietenia Ma- 128. no. 1). 
hogoni), Redrawn from Engler. 2 
ene 
oe 
Family Burseraceae. Terebinth Fam- 
ily. Contains 16 genera and about 300 species, natives exclusively of 
tropical Asia, Africa and America. They are forest trees of high value 
as resin and balsam bearing plants. Thus myrrh is the product of 
Commiphora Abyssinica, and bdellium is derived from ©. Africana. 
The resin known as olibanum, which is supposed to have been the 
frankincense of the ancients, comes from the Arabian Boswellia Carteri. 
Various gums are yielded by Bursera, the only genus which penetrates 
the Florida peninsula. The fruits of Canarium are edible. The Bur- 
seraceae as a whole have no good characters distinguishing them from 
the two preceding families, except that the husk of the fruit splits into 
valve-like segments. A section of the flower of Boswellia Carter, show- 
ing structure, is seen in Fig. 128, no. 2. 
Family Meliaceae. Melia Family. Contains about 40 genera and 
200 species. They are trees or shrubs differing from most of the fam- 
