BOTANY. 171 
a, flowering branch ; }, male flower; ¢, anther; d, female flowers ; ¢, pistil ; 
J, fruit; g, section of ditto. 
Orper 158. Raamnacea#, the Buckthorn Family. Calyx four- or five- 
cleft, valvate in estivation. Petals distinct, hooded, or convolute, inserted 
into the throat of the calyx, sometimes 0. Stamens definite, opposite the 
petals. Disk large, fleshy, flat, or urceolate. Ovary superior or half 
superior, two-, three-, or four-celled; ovules solitary, erect, anatropal. 
Fruit fleshy and indehiscent, or dry and separating into three parts. Seeds 
erect ; albumen fleshy, rarely 0; embryo about as long as the seed, with a 
short inferior radicle, and large flat cotyledons. Trees or shrubs, ‘often 
spiny, with simple, alternate, rarely opposite leaves, and minute stipules. 
They are generally distributed over the globe, and are found both in 
temperate and tropical regions. There are 43 genera and 250 species 
enumerated. Of these four genera and thirty-four species are cited as 
North American by Torrey and Gray. 
Tribe 1. Paliwree. Shrubs of the Old World with alternate leaves. 
Fruit semi-adherent, dry, crowned by a_ transversely ana wing. 
Example: Ventilago. ) 
Tribe 2. Frangulee: Trees or shrubs spread over the temperate zones ; 
with alternate leaves. Fruit without wings, free or semi-adherent, fleshy 
or capsular, with the shell indehiscent or opening by an internal fissure. 
Examples: *Berchemia, *Sageretia, *Rhamnus, *Ceanothus. 
Tribe 3. Pomaderrew. Unarmed Australian shrubs with alternate leaves. 
Fruit wingless, capsular, the shell opening by an introrse perforation, covered 
by a membrane. Example: Trymalium. 
Tribe 4. Colletiew. Shrubs of temperate South America, the branches 
terminated by a spine, leaves decussate, sometimes almost none. Fruit 
wingless, free. Example: Colletia. 
Tribe 5. Phylicee. Shrubs of the Cape and of extra-tropical Australia ; 
unarmed, leaves alternate. Fruit wingless, adherent, and crowned by the 
calyx, capsular. Example: Spyridium. 
Tribe 6. Gouaniew. Lianas or herbs of the tropics, or of South Africa ; 
unarmed. Fruit adherent, separating by shells usually winged longi- 
tudinally on the back, opening by an internal fissure. Example: 
Helinus. 
Rhamnus catharticus or the Buckthorn, naturalized in the United States, 
is sometimes used medicinally. The greenish juice, when mixed with lime 
and evaporated to dryness, forms the color called sap green. French berries 
used in dyeing yellow are obtained from R. infectorius. Various species are 
native in North America. Jujube is the fruit of Zizyphus jujuba. The 
Lotus of the ancients is a second species, Z. lotus. The leaves of Ceanothus 
americanus were used in the revolutionary war as a substitute for tea. 
Rhamnus catharticus, Buckthorn (Europe) (pl. 71, jig. 7); a, a flowering 
branch ; 6, a male; c, a female flower; d, a fruit; ¢, ditto with part of the 
flesh removed ; 7, the seed; g, do. in cross-section. 
Orper 159. SrapnyLesces, the Bladder-nut Family. Sepals five, united 
171 
