360 AKTOCARPACEAE 



pericarp crustaceous. Endosperm fleshy. Embryo curved or coiled. The 



perianth is sometimes much reduced or obsolete. 



Stems twining : leaf-blades usually 3-lobed : fruit a drooping cone with thin imbricated bracts. 



1. HUMULUS. 



Stems erect : leaf-blades 3-7-parted : fruit spicate on stiff branches. " 2. Cannabis. 



1. HUMULUS L. 



Perennial twining herbs, with coarse pubescence. Leaves opposite : blades serrate or 

 3-7-lobed : stipules free, persistent. Staminate flowers in panicled racemes, with a perianth 

 of 5 imbricated sepals, and 5 stamens with short erect filaments. Pistillate flowers in 

 ament-like drooping spikes, 2 together, subtended by a bract, with an entire scale-like 

 perianth and a sessile 1-celled ovary. Achene a little flattened, subtended by a membra- 

 nous bract. Embryo spirally coiled. 



1. Humulus Lupulus L. A prostrate or climbing vine roughly pubescent through- 

 out with stifl" recurved liairs. Stems 2-9 m. long, dextrorsely twining, angled : leaf-blades 

 firm, orbicular or ovate in outline, 3-15 cm. in diameter, simply serrate or 3-7-lobed, the 

 lobes serrate, cordate at the base ; petioles about i as long as the blades : panicles 1-2 dm. 

 long, open : sepals oblong varying to ovate or obovate, obtuse, pubescent, about 3 mm. long : 

 stamens surpassing the sepals : fruiting spikes 3-8 cm. long, ovoid or cylindric ; bracts 

 membranous, suborbicular to oblong-ovate, obtuse, 1-2 cm. long : achenes subglobose, about 

 2-3 mm. in diameter. 



In thickets, Nova Scotia to Manitoba, Florida and Arizona. Escaped from cultivation. Native 

 of Europe and Asia. Summer. Hop. 



2. CANNABIS L. 



Coarse pubescent annual herbs, with erect stems. Leaves alternate or opposite : blades 

 digitately divided into 5-11 narrow, serrate, firm segments : stipules free, persistent. 

 Staminate flowers in panicled racemes, with a perianth of 5 imbricated sepals, and 5 sta- 

 mens with short erect filaments. Pistillate flowers solitary in the axils of leafy bracts, 

 forming spikes, with an entire perianth subtending a sessile 1-celled ovary. Achene oval, 

 slightly flattened. Embryo curved. 



1. Cannabis sativa L. A coarse erect herb, with a very tough inner bark. Stems 

 branched, 1.5-4 m. tall, rough pubescent, angled : leaf-blades divided into 5-11 linear or 

 linear-lanceolate serrate acuminate segments varying from 4-15 cm. long ; petioles 2-8 cm. 

 long : panicles about as long as the subtending leaves : calyx 4-5 mm. broad : sepals ob- 

 long or oval, pubescent obtuse : stamens about as long as the sepals : spikes leafy-bracted, 

 1-2 cm. long : achenes oval-lenticular, 4-5 mm. long, variegated, enveloi^ed in the persist- 

 ent perianth. 



In waste places. New Brunswick to Minnesota, Kansas, Georgia and Tennessee. Native of Asia 

 and Europe. Summer. Hemp. 



Family 3. AKTOCARPACEAE Horan. Mulberry Family. 



Shrubs or trees, with a milky sap and often edible fruit. Leaves mostly al- 

 ternate : blades entire, toothed or lobed : stipules deciduous. Flowers monoe- 

 cious or dioecious, in ament-like spikes or heads, on the outside of a receptacle, or 

 on the inside of a closed receptacle, the staminate with a perianth of 3-4 sepals, 

 somewhat united at the base. Stamens 3-4, inserted at the base of the perianth. 

 Filaments inflexed, straightening out elastically. Pistillate flowers with a peri- 

 anth of 3-5, partially united sepals which enlarge and envelop the achene at 

 maturity and a 1-2-celled ovary. Styles or stigmas single or 2. Ovule solitary. 

 Fruit a syncarp or syconium. Achenes inclosed in the pulpy calyx. Endosperm 

 fleshy, or wanting. Embryo curved. 



Staminate and pistillate flowers on the outside of the receptacle. 



Staminate and pistillate flowers in ament-like spikes. 1. MoRUS. 

 Staminate flowers in ament-like racemes ; pistillate flowers in heads. 



Plants armed : leaf-blades entire. 2. ToxYi.oN. 



Plants unarmed : leaf-blades serrate and often lobed. 3. Broussonetia. 



Staminate and pistillate flowers on the inside of a closed receptacle. 4. Ficus. 



1. MORUS L. 



Monoecious or dioecious shrubs or trees, with a thin scaly bark. Leaves alternate : 

 blades entire or 3-lobed, serrate, membranous, or somewhat leatliery, deciduous. Flowers 



