sect, ii PHANEROGAMIA 503 



Officinal. — From Cannabis sativa var. indica is obtained Herba Cannabis 

 indic ae. The glands of the cone - scales of Sumulus Lupulus have an officinal 

 value as Lupulinum. 



Family Urtieaeeae. — Flowers unisexual through reduction, usually 

 with four-leaved perigone and with stamens inflexed in the bud; 

 ovary monomerous, with an erect, atropous ovule. Herbs 

 and shrubs without latex, with stipulate leaves. 



The Urtieaeeae are mostly herbs and shrubs with simple leaves, 

 which are often armed with stinging hairs. The flowers are restricted 

 to wind-pollination, and are clustered in thick, greenish or whitish 

 inflorescences. The fruit is a nut or a drupe. 



Geographical Distribution. — The Stinging Nettles, Urtiea urens and dioica, 

 occur everywhere as common weeds. The majority of the representatives of this 

 family, however, inhabit the warmer zones, where they constitute a considerable 

 proportion of the herbaceous and shrubby vegetation of the primitive forests. 



Order 3. Polygoninae 



Flowers hypogynous, hermaphrodite, sometimes unisexual by 

 suppression, generally trimerous ; perianth absent or DEVELOPED AS A 

 perigone ; ovary unilocular, with a single basal atropous ovule. 



The Polygoninae occupy an intermediate position between the Urticinae and the 

 following order, Centrospermae. Resembling the Urticinae in their small, usually 

 greenish, thickly clustered flowers and in the construction of the ovary, they may 

 always be distinguished from them by their trimerous flowers. They differ from 

 the Centrospermae in having atropous ovules and in the trimerous structure of their 

 flowers. 



The members of this order are mostly herbs, rarely small woody 

 plants. They generally have axes swollen at the nodes, simple, 

 usually entire leaves, and spike-like inflorescences with closely-crowded 

 small flowers. The flowers themselves vary greatly in structure ; some- 

 times naked, and of the simplest structure ; sometimes, by the dis- 

 similarity of the outer and inner leaves of the perigone, and by the 

 possession of two whorls of stamens, they exhibit a higher stage of 

 development than is attained by the Urtieinae. The fruit is either a 

 nut or drupaceous in character ; the seeds contain a mealy albumen. 



Family Piperaeeae. — Flowers naked, typically trimerous, but 

 usually reduced ; fruit drupaceous ; seeds with perisperm. Herbs 

 and shrubs with stipulate or exstipulate leaves (Figs. 453, 454). 



The Piperaeeae are found exclusively in tropical countries, where, as herbs and 

 shrubs, often climbing by means of roots or living as epiphytes with inconspicuous, 

 densely clustered, green flower-spikes, they constitute an essential though not 

 particularly prominent part of the Flora. Piper nigrum L., the Black Pepper 

 (Fig. 453), is a shrubby root-climber native of the East Indies, and is now cultivated 

 in all tropical countries. The unripe drupes of this species are familiarly known 

 as black pepper ; white pepper consists of the kernels of the fruit of the same 

 plant, freed from the exocarp. The perisperm is large and mealy. 



