456 



CI. APOCYNACE^. 



Apocynum. 



Order CI. APOCYNACE^.— Dogbanes. 



Trees, shrubs and herbs with a milky juice 

 Ca/.— Sepals 5, united at base, persistent 

 Cor. 5 lofied, regular, twisted in aestivation, deciduous. 

 Sta. 5, arising trom the corolla and alternate with its segments. 



Fit. distinct. 



Lvs. opposite, entire, without stipules. 



AntMrs 2-celled, opening lengthwise, 

 sometimes slightly connected. 



Pollen granular, globose or 5-lobed, immediately ap- 

 plied to the stigma. 



Ova. 2, distinct or rarely united. Styles distinct or 

 united. Stigmas united into l which is com- 

 mon to both styles. 



fV.— Follicles 2, rarely l of them abortive. 



Sds. numerous, pendulous, with or without a coma, 

 albuminous. Embryo foliaceous. 



Genera 100, species 566, chiefly natives of the torrid 

 zone. 



Properties.— Ihese plants possess active and often 

 suspicious qualities residing in ihe white juice with 

 which the order is pervaded, and in the seeds which 

 are often deadly poisons. The alkaloid strychnine or 

 strichnia. one of the most violent of poisons, is the 

 active principle of the seeds of the Stnchnos Nux- 

 vomica of India. It is sometimes administered as a 

 medicine, but with doubtful success. S. Tieute of 

 Java is one kind of Upas. Cerbera Tanghin, a tree of 

 Madagascar, is powerfully poisonous, a single seed 

 being sufficient to destroy twenty persons. The Apo- 

 cyneae are emetic, and becoming highly valued in 

 hydrocephalus, &c. The juice contains caoutchouc in 

 small quantities, but in Sumatra this is obtained 

 largely from the juice of Urceola elastica. 



FIG. 54. — 1. Apocynum androsa;mifolium. 2. A 

 flower, somewhat enlarged. 3. The flower cut open, 

 showing the stamens wilh distinct filaments and united 

 anthers. 4. The ovaries and stigma. 5. Plan of the 

 flower. 6. INIatured follicles. 7. A seed with the long, 

 silky coma. 



Conspectm of the Genera. 



t with white or flesh-colored flowers Apocynum. I 



Herbs ? with blue flowers. Amsonia. 2 



j with opposite leaves and bluish-purple flowers Vinca. 3 



Shrubs I with ternately ver cillate leaves and rose-colored flowers Nerium. 4 



1. APOCYNUM. 



Gr. OTTO, away, kvo)v, dog; Pliny says this plant is fatal to dogs. 



Calyx very small ; corolla campanulate, lobes short ; stamens 

 included ; filaments short, arising from the base of the corolla, and 

 alternate with 5 glandular teeth ; anthers sagittate, connivent, coher- 

 ing to the stigma by the middle ; ova. 2 ; stigmas connate ; follicles 

 long, sublinear, distinct. — Herbs, suffrutescent, erect, ivith opposite, 

 entire, mucronate lvs. Cymes terminal and axillary. Pedicels not 

 longer than the pale Jlowers. 



1. A. ANDROs.EMiroLiUM. Dos''s-bane. 



Smooth ; lvs. ovate ; cyjnes lateral and terminal ; livib of cor. spreading, 

 the tube longer than the calyx. — A smooth, elegant plant, 31 high, in hedges 

 and borders of fields. Stem reddened by the sun, erect, branching above. 

 Leaves dark green above, paler beneath, opposite, rounded at base and acute at 

 apex, 2 — 3' long and § as wide, on petioles \' long. Cymes paniculate, at the 

 top of the liranches and in the axils of the upper leaves. Pedicels \' long. 

 Calyx much shorter than the corolla. Corolla as long as the pedicels, bell-- 

 shaped, white, striped with red, with 5, acute, spreading segments. Medicinal. 

 U. S. and Brit. Am. June, July. 

 /?. incanum. Lis. hoary pubescent beneath. 



2. A. CANNABiNUM. Indian Hemp. 



Lvs. oblong, obtuse at each end, mucronate ; cymes paniculate,* many- 

 flowered, terminal and lateral; cal. seg. lanceolate, equaling the tube of the 

 corolla; cor. seg. erect. — A species with smaller leaves and erect flowers, found 



