EUPHORBIACEAE (SPURGE FAMILY) 543 



4. ARGYTHAMNIA P. Br. 



Flowers monoecious. Calyx 5-parted, valvate in the staminate flowers, im- 

 bricate in the pistillate. Petals alternate with the calyx-lobes and with the 

 prominent lobes of the glandular disk. Stamens 5-16, united into a central 

 column in 1-3 whorls. Styles 1-3-cleft. Capsule depressed, 3-lobed. Seeds 

 subglobose, roughened or reticulated, not carunculate. Erect herbs or under- 

 shrubs, with purplish juice, and alternate usually stipulate leaves. (Name from 

 Apyvpot, silver, and 6dfj.vos, bush, from the hoariness of the original species.) 



1. A. mercurialina Muell. Arg. Stem erect, nearly simple, 3-0 dm. high, 

 sericeous ; leaves sessile, oblong-ovate to lanceolate, entire, pubescent with 

 appressed hairs or glabrate, somewhat rigid ; raceme many-flowered, exceeding 

 the leaves ; spatulate petals of the sterile flowers as long as the calyx-lobes ; 

 ovary sericeous; capsule appressed-pubescent, 8-10 mm. in diameter. (Ditaxia 

 Coult.) Kan. to Ark. and Tex. 



5. MERCURIALIS [Tourn.] L. MERCDBY 



Dioecious or monoecious. Flowers apetalous, in interrupted axillary spikes. 

 Stamens 8-20, distinct. Calyx small, green, globose in bud, 3-parted. Carpels 

 2 (-3). Herbs, with opposite pinnately veined leaves. (A plant-name used 

 by Pliny and meaning belonging to the god Mercury.) 



1. M. ANNUA L. Weak erect leafy-stemmed annual ; leaves lanceolate or 

 ovate-lanceolate, crenate-serrate ; carpels hispid. Waste places and ballast 

 ground, N. S. to S. C. and O. (Adv. from Eu.) 



6. ACALYPHA L. THREE-SEEDED MERCUKY 



Flowers monoecious ; the sterile very small, clustered in spikes ; the few or 

 solitary fertile flowers at the base of the same spikes, or sometimes in separate 

 ones. Calyx of the sterile flowers 4-parted and valvate in bud ; of the fertile, 

 3-5-parted. Corolla none. Stamens 8-16 ; filament short, monadelphous at 

 base ; anther-cells separate, long, often worm-shaped, hanging from the apex 

 of the filament. Styles 3, the upper face or stigmas cut-fringed (usually red). 

 Capsule separating into 3 globular 2-valved carpels, rarely of only one carpel. 

 Herbs (ours annuals), or in the tropics often shrubs, resembling Nettles or 

 Amaranths ; the leaves alternate, petioled, with stipules. Clusters of sterile 

 flowers with a minute bract ; the fertile surrounded by a large and leaf-like 

 cut-lobed persistent bract. ('A/caXi^ij, an ancient name of the Nettle.) 



* Fruit smooth or merely pubescent; seeds nearly smooth. 



1. A. virglnica L. Smoothish or hairy, 3-6 dm. high, often turning purple ; 

 leaves ovate or oblong-ovate, obtusely and sparsely serrate, long-petioled ; 

 sterile spike rather few-flowered, mostly shorter than the large leaf-like pal- 

 mately 5-9-cleft fruiting bracts; fertile flowers 1-3 in each axil. Fields 

 and open places, N. S. to Ont. and Mmn., s. to the Gulf. July-Sept. 



2. A. gracilens Gray. Finely pubescent and often villous ; leaves lanceolate 

 or even linear, less toothed and shorter-petioled ; the slender sterile spike 

 often 2 cm. long, and much surpassing the less cleft or few-toothed fruiting 

 bracts. (A. virginica, var. Muell. Arg.) Sandy or dry soil, s. N. H. to Fla., 

 w. to e. Kan. and Tex. Carpels by abortion sometimes reduced to one (A. 

 monococca Engelm.). 



* * Fruit echinate with soft bristly green projections; seeds rough-wrinkled. 



3. A. ostryaefdlia Riddell. Leaves thin, ovate-cordate, sharply and closely 

 serrate-toothed, abruptly acuminate, long-petioled ; sterile spikes short, axillary ; 

 the fertile ones mostly terminal and elongated, their bracts deeply cut into 

 many linear lobes. (A. caroliniana Ell., not Walt.) N. J. to Fla., w. to O., 

 Kan., and Tex. 



