SIMARUBACEAE 197 



KEY TO GENERA 



I. Stamens 10, twice as many as the petals; fruit a samara 



Ailanthus. 



II. Stamens 4-5, as many as the petals; fruit a berry-like drupe. . . . 

 Picrasma. 



AILANTHUS 



Deciduous, coarse-branched trees with large compound leaves. 

 Flowers polygamous, or dioecious, small and inconspicuous in large 

 terminal panicles, with 5 sepals and 5 petals on a 10 lobed disk. 

 Stamens 10 in the staminate flower, 2-3 in the perfect flower, and absent 

 or 2-3 in the pistillate flower; ovary 2-5, more or less distinctly cleft, 

 rudimentary in the staminate flower; ovules 1 in each cell. Fruit 1-5 

 samaras, each composed of a seed, surrounded by a large, membranous 

 wing. The large terminal clusters of the fruit are often very conspicuous 

 in autumn and winter. 



About 11 species, mostly in the tropics of China, India, Malay and 

 Australia. 



Ailanthus altissima Swingle. 



(Ailanthus glandulosa Desl'ontaines.) Chou Chun. 



Tree up to 30 m. tall with smooth, gray or brownish bark marked by 

 shallow, pale colored, longitudinal fissures. Leaves odd pinnate with 7-9, 

 or more pairs of leaflets. Leaflets ovate-lanceolate, pointed, green, with 

 entire margins except 1-4 pairs of glandular teeth near the base. The 

 leaves have a disagreeable odor when bruised and the same disagreeable 

 odor is exhaled by the staminate tree at the time of the shedding of the 

 pollen. The samara is oblong, red or purplish-brown, with the wing 

 slightly twisted at the base each side of the seed which imparts to it a 

 spiral motion when detached and falling through the air. 



Wild in the mountains of Chihli; elsewhere cultivated. Introduced 

 into India, England, France, Germany, Italy and the United States of 

 America. In France this tree is used to hold railroad embankments. 

 Ailanthus is a rapid growing tree attaining a large size in China, but the 

 wood is soft and light, suitable only for such uses as do not require strength 

 and durability. The wood is greenish-white or yellow, easily worked and 



