Dicotyls or Exogenous Plants. 73 



1. Genus OX'-A-LIS. — Sepals 5, persistent; petals 5, sometimes 

 united at base ; stameus 10, monadelphous at base; styles 5, distinct; 

 leaves radical or alternate; juice sour. 

 A. Stetnless, leaves and scapes from a bulb. 



Ox'-a-lis vi-o-la'-ce-a L. Violet Wood-sorrel. — Scapes umbellately 

 several-flowered, 5-t( in. high; petals violet. 



A. Stems leafy, branching, pediiyicles axillary, Jlowers yellow. 



Ox'-a-lis cor-nic-u-la'-ta L. Wood-sorrel. — -Erect or procumbent ;^ 

 strigose-pubescent; stipules round or truncate, ciliate. 



Ox'-a-lis stric'-ta L. Wood-sorrel. — Stem erect, like the preceding,, 

 but stipules none ; variable. 



Ox'-a-lis gran'-dis Small. [O. recm'va Gray's Man.) Large Wood- 

 sorrel. — Differs from the preceding in having leaflets larger; ^-1>^ in. 

 broad, usually with a brownish margin ; flowers larger, 6-8 lines long, 



XL. Order RU-TA'-CE-/E. RUE FAMILY. -vShrubs; leaves trifoliate 

 or pinnate ; flowers polygamous or dioecious ; pistils 2-5, separate or 

 united. 



Flowers dioecious, pistils 2-5, separate, pods fleshy Xantho.tyluni. 1 



Flowers polygamous, ovary 2-celled, fruit winged all around Ptelea. 2 



1. Genus XAN-THOX'-Y-LUIVI. — Shrubs or trees with pinnate leaves, 

 the stems and often leafstalks prickly; flowers small, greenish or 

 ■whitish. 



Xan-tliox'-y-lum a-mer-i-ca'-num Mill. Prickly Ash ; Tootiiache Tree. — 



Flowers appearing before the leaves ; bark, leaves and pods very pun- 

 gent and aromatic. 



2. Genus PTEL'-E-A. — Shrubs with trifoliate leaves, and greenish- 

 white small flowers in compound terminal cymes. 



Ptel'-e-a tri-fo-li-a'-ta L. Hop Tree; Shrubby Trefoil. — Leaflets ovate, 

 pointed, downy when j-oung; fruit a samara, nearly orbicular. 



XLL Order SI-MA-RU-BA -CE-/E. AILANTHUS FAMILY. — Trees; 

 leaves pinnate; sepals •">, flowers panicled; fruit a samara. 



1. Genus AI-LAN'-THUS. — Sepals o, more or less united at base, 

 petals 5; fruit a 1-celled, 1-seeded samara; leaves pinnate, 2-4 ft. long. 



