284 
APETALOUS OEDEES. 
325. Salicace^j the Willow Tribe. — Trees or shrubs. Lemei 
alternate, simple, stipulate. Flowers dioecious, amentaceous, 
and destitute of floral envelopes, or with a membraneous cup 
like calyx. Stamens distinct or monadelphous. Ovary 1-celled ; 
ovules numerous, erect; stigmas 2 or 4. Fruit coriaceous, 
1- celled. Seeds numerous, small, covered with a silky coma, 
exalbuminous. 
a. Properties : the bark is usually astringent and tonic. 
Genera. — Salix, Populus. 
526. Balsamiflu^, the Sweet-Gum Tribe. — Trees. Leaves 
alternate, simple or lobed, stipules deciduous. Flowers monoe- 
cious, amentaceous. Catkins or heads roundish. Anthers nu- 
merous, nearly sessile, destitute of floral envelopes. Ova/ries 
2- celled, each surrounded by a few scales. Fruit a cone com- 
posed of hard, connected scales, in the cavities of which lie 
2-lobed, 2-celled capsules. Seeds numerous, winged, albumi- 
nous. 
a. Properties : the bark is hot, bitter, and stomachic ; a fragrant reein is yielded 
by several species. 
Genus. — Liquidamber 
527. Platanace^, the Plane-tree Tribe. — Trees with a watery 
juice. Leaves alternate, palmate. Flowers monoecious, amen- 
taceous, naked. Catkins round, pendulous. Stamens mixed 
with small scales. Ovary 1-celled ; style thick, subulate. N^uts 
clavate, compressed. Seeds 1-2, pendulous, albuminous. 
Genus. — Platan us. 
528. TJeticace^, the Nettle Tribe. — Herbs., shrubs^ or trees. 
Leaves alternate, stipulate, covered with stinging hairs. Flowers 
monoecious, dioecious, or polygamous, scattered, or collected 
into catkins or heads. Calyx membraneous, lobed, persistent. 
Stamens inserted into the base of the calyx opposite its lobes ; 
definite, distinct. Ovary superior ; ovule solitary, erect ; stigma 
fringed. Fruit an in dehiscent nut, surrounded by the mem- 
braneous or fleshy calyx. Embryo straight, with fleshy albu 
men. 
a. Properties : excessive causticity in the limpid juice is the chief characteristia 
Genera. — Urtica, Parietaria, Datisca. 
Sub-order CANNABiNiE, the Hemp Tribe. — Seeds suspended, 
destitute of albumen ; embryo hooked or coiled. 
Genera. — Cannabis, Humulus. 
Fig. 206, Humulus lupulus (hop) ; a represents the pistillate flowers foi-ming 
oval, drooping, and peduncled green cones or strobilums ; stem twining. 
Sub-order Moke^, the Mulberry Trihe. — Seed solitary, pen 
dulous, albuminous ; embryo hooked ; juice milky. 
Genera. — Morui3, Broustonetia, Ficua. 
