728 URTICACE^. (NETTLE FA^^IILY.) 



6. MERCIJR1AI.IS, L. Mercury. 



Flowers dicecious. Perigonium 3-4-partecl, valvatein stamiuate, and 

 imbricate in jDistillate flowers. Petals 0. Staminate fioicem : stamens 

 8-12; anther-cells 2, joined by a globular connective. Pistillate flowers : 

 ovary 2-celled, each cell with one ovule; style short: stigmas 2, 

 roughened on their inner aspect; stamens 2-3, reduced to filaments; 

 capsule 2, rarely 3-celled — Herbs, with colorless juice, and opposite, 

 stipulate leaves. 



M, annua, L. © Annual Mercury. .3 to .5; stem erect, branch- 

 ing, thickened at nodes. Leaves tender, glabrous, short-petioled, 

 ovate to ovate-lanceolate, .02 to .06 long, crenate-serrate, slightly 

 ciliolate. Staminate floicers clustered on axillary peduncles, which are 

 longer than the leaves; pistillate flowers solitary or twin, sessile in the 

 axils; capsules beset with tubercles terminating in bristle-like papillae; 

 seeds elliptical, pitted and tubercled — All the year — Fields and 

 waste places; common everywhere. 



Order XCV. URTICACE^, Juss. (Xettle Family.) 



Plants with stipules^ and raoiioecious, dicecious^ ])oly g a- 

 rnous, or ■perfect floioers, fuimished vntli a regular perigo- 

 nium^ free from the l-celled, 1-ovuled ovary, lohich forms a 

 1-seeded fruit. The stamens as many as the lohes of perigo- 

 niitm or sepals, and oxjposite them — Herbs, shrubs, or trees, 

 the stipules often deciduous. The mode of growth of the 

 different tribes of this principally tropical order differs widely. 



* Trees with perfect flowers, on last year's leafless branches. 



1. ULMUS. Fruit a samaroid. Anthers extrorse. 



* * Tree<i, with moncecious, dicecious, or polygamous flowers. 



2. CELTIS, Fruit a drupe. Anthers introrse. 



3. MORUS. Fruit a compound berry, resembling a blackberry. 



4. FICUS. Fruit a fleshy receptacle containing the flowers. 



* * * Shrubs or herbs, with monacious or diaeious floicers . Fruit an ahene. 

 ^ Filaments short, straight in bud. Ovvle pendulous. Stigmas 2. Embryo coiled or bent . 



5. HUMULUS. Anthers erect. Leaves 3-5-lobed. Twining shrubs. 



6. CAN^JfABIS. Anthers drooping. Leaves 5-7-digitate-divided. Erect annuals. 



\ ^ Filaments inflexed in biuL Ovule erect. Style or stigma 1. Embryo straight. 



7. URTICA. © @ 1^ . Perigonium of fertile flowers of 2-4, separate or nearly separate 



sepals. Herbs with stinging hairs. 



8. PAFvIETAEIA. 2|! Perigonium of fertile flowers tubular or cup-shaped, enclosing the 



akene. Unarmed, perennial herbs. 



9. FORSKAHLEA. If Perigonium of fertile flowers 0, of staminate tabular, 1-lipped. 



1. UL.MUS, L. Elm. Kha/rhafti. IBuqud. 



Flowers perfect. Perigonium camiDanulate, 4-o-dentate, mar- 

 cescent. Stamens 4-8, inserted at base of iDcrigonium, filaments straight 

 in bud. Ovary 2-beaked, stigmas 2, elongated, villous along their 

 inner aspect. Fruit a samaroid, comjDOsed of a utricle, surrounded by 



