ORDER 145. SMILACE^E. 701 



Genera 7, specie* 150. The only remarkable or useful product of this order is Yams, an 

 important article of food in all tropical countries. They are the large, mucilaginous, sweetish 

 tubers of Dioscorea sativa, &c. 



8. DIOSCO'REA, L. YAM ROOT. (In honor of PedaoiusDioscorides, 

 a Greek physician and florist of about the reign of Nero.) Flowers $ 

 $ ; styles of the fertile flowers 3 ; cells of the capsule 2-seeded ; seeds 

 membrauaceously margined. Slender, shrubby climbers, twining with 

 the sun. Lvs. simple and palmately veined or palmately divided. Fls. 

 green, inconspicuous, in axillary spikes or panicles. 



1 D. villosa L. "\\'ILD YAM. Lvs. broad-ovate, cordate, acuminate, 9 11-veined, 

 the margin entire or wavy, lower surface downy or glabrous, never villous ; upper 

 surface glabrous ; petioles elongated, the lowest somewhat verticillate in 4s, the 

 next subopposite, the middle and upper alternate ; 3 plant with the spikes pani- 

 culate, 5 with the spikes simple. A delicate twining vine, in thickets and 

 hedges, U. S. and Can., rare in N. Eng. Stem woolly, reddish-brown, 1 2" 

 diarn.; 5 10 15f long, running over bushes and fences. Leaves 2 4' long, 

 as wide, distinctly cordate and acuminate. Petioles 2 4' long. Peduncles axil- 

 lary. Ovaries at first elliptic, finally almost as broad as long. June, July. (D. 

 quarternata Ph.) 



2 D. sativa L. YAM. Lvs. alternate, roundish-ovate, long-cuspidate, sinu- 

 ate-cordate, glabrous, 9. to 13-nerved, outer nerves bifid, transverse veins simple; 

 st. terete, smooth ; $ spikes densely paniculate ; $ spikes aggregate. Yar. ACU- 

 LEATA, stems aculeate. Native of E. India. This species, with its varieties, is 

 understood to be that which is known as the Sweet Yam, cultivated in Ga. and 

 Fla., and all tropical countries, on account of its sweet and nutritious tubers. \ 



ORDER CXLY. SMILACE^E. SARSAPARILLAS. 



Herbs or shrubs, often climbing. Leaves reticulate-veined. Flowers dioecious 

 or monoecious. Perianth free from the ovary, 6-parted, regular. Stamens 6, in- 

 serted into the base of the segments, Anih. 1-celled (2-lameilate). Ovary 3-celled ; 

 cells 1 or many r seeded. Style 1 or none. Stigmas 3. Berry roundish, few or 

 many-seeded. Seeds orthotropous albuminous. Fig. 586. 



Genera 2, specifs 120, thinly disseminated through most countries. The diuretic and emul- 

 cent sarsaparillas are the roots of several, chiefly 8." American species of Smilax. 



SMPLAX, L. GREEN BRIER. SARSAPARILLA. (Gr. Ofiihr), a grater; 

 from its prickly stems.) Flowers $ $ , perianth deciduous, of 6 simi- 

 lar, spreading, sepaloid segments ; $ stamens 6, on the base of the seg- 

 ments and shorter than they ; anthers adnate ; $ stamen 0, or sterile 

 filaments ; stigmas 3, sessile ; berry globular, 1 to 3-celled, 1 to 6- 

 sceded. 2| Herbs or shrubs, mostly climbing by stipular tendrils, often 

 prickly. Lvs. entire, petiolate, palmately veined. Fls. green or yellow- 

 ish, in axillary, stalked umbels. (In the elaboration of this genus we 

 have been greatly aided by the accurate observations of Dr. Feay, of 

 Savannah.) 



CopnosMANxnrs. Herbaceous (unarmed). Leaves long-peliolgd. Flowers foetid. (*) 



Leaves glabrous on both sides. Stems climbing Nos. 14, 15 



Leaves downy or hispid on the veins beneath. Erect or climbing Nos. 12, 13 



.MILAX proper. Shrubby, armed or not. Leaves short-petioled, ~Seeds 1 to 3. (*) 



: Pubescent, prostrate, unarmed. Leaves cordate, evergreen. South No. 11 



Glabrous, climbing. Leaves acute at base. Peduncle shorter than petiole Nos. 9, 10 



Glabrous, climbing. Leaves abrupt or cordate at base, (a) 



a Leaves panduriforrn or somewhat contracted in the middle Nos. 7, 8 



a Leaves ovate or oblong, deciduous, (b) 



b Plants unarmed Nos. 5, 6 



b Plants prickly. Leaves glaucous, especially beneath No. 4 



Leaves green on both sides .Nos. 1 3 



1 S. rotundifolia L. COMMON* GREEN* BRIER. St. terete or sub-4-sided, flex- 

 uous, aculeate, ligneous, climbing ; Ivs. short-petiolate, roundish-ovate, 5 to 7 -veined, 



