106 
On»zn CLIII. ASCLEPIA'DEE (this order contains plants 
agreeing with Asclépias in important characters). R. Br. in 
wern. soc. mem. l. p. 19. prod. 458.—Apocynez, part. Juss. 
gen. p. 143. Adans. fam. p. 160.  Contórtee, part. Lin. 
Calyx 5-cleft or 5-parted (f. 16. a. f. 17. a.), permanent. 
Corolla monopetalous (f. 16. b. f. 17. c. f, 20. b.), hypogynous, 
5-lobed (f. 16. b. f. 17. b. f. 20. b.), regular, imbricate in zes- 
tivation (f. 20. b.), rarely valvate, deciduous. Stamens 5, in- 
serted in the bottom of the corolla, alternating with the seg- 
ments of the limb; filaments usually connected; anthers 
2-celled (f. 17. h. f. 15. d.), but sometimes almost 4-celled 
from a semi-complete dissepiment in each of the true cells ; pollen 
at the bursting of the anthers coalescing in an equal number 
of masses to the cells of the anthers, rarely twin or confluent 
by pairs, or by fours, or solitary, fixed to the 5 processes of 
the stigma. Ovaria 2. Styles 2, close together, often very 
short ; stigma common to both, dilated, pentagonal: having the 
angles bearing corpuscles. Follicles 2, one of which is often 
abortive : having the placenta applied to the suture, but is at 
length free. Seeds numerous, imbricate, pendulous, usually 
furnished with a tuft of hairs at the umbilicus. Albumen twin. 
Embryo straight, with foliaceous cotyledons, a superior radicle, 
and inconspicuous plumule.—Shrubs, rarely herbs, for the most 
part lactescent and climbing. Leaves entire, usually opposite, 
but sometimes also alternate and verticillate, usually furnished 
with intrapetiolar cilia in place of stipulas. Flowers subum- 
bellate, fascicled or racemose, interpetiolar. 
This differs from all other dicotyledonous orders in the pollen 
of all the anthers in each flower being combined in a definite 
number of masses of a waxy substance, which, at the bursting 
of the anthers, are fixed to the 5 glandular processes of the 
stigma ; in this structure it has some analogy with Orchidee, a 
monocotyledonous order. It differs from Apociynee, to which 
it is nearly allied, in having the stamens united into a fleshy 
crown, and in the substance of the anthers. 
Periploca glabra is the only instance of an Asclepiadeous 
plant being a hardy shrub; every other woody species of the 
order being natives of hot countries. The genus Hoya com- 
prehends fleshy-leaved, climbing, or creeping plants, with 
umbels of waxen odoriferous flowers, distilling honey. Per- 
gulària is valued for its fragrance; Ceropégia and other genera 
for their singularity; and Asclépias for beauty and hardiness. 
But the most remarkable genera of the order are Stapèlia, 
Duvàlia, Pectinària, O'rbea, Tridéntia, Huérnia, Piaránthus, &c. 
in which the stems are fleshy and of various forms, and the 
leaves supplied by small thick points or scales, and whose 
flowers are not less singular for their curious organization, than 
they are for their colouring and spotting, and offensive for their 
odour. The root of Diplólepis vomitórium, Asclépias curas- 
sávica, Colótropis prócera, and some others is employed in 
different countries for ipecacuanha. An infusion of the root of 
Asclépias decámbens has the singular property of exciting 
perspiration, whence it is successfully used in Virginia for 
pleurisy. 
Notwithstanding the poisonous nature of the greater number 
12 
ASCLEPIADEZ. 
of the species of this order, yet the young shoots of some are 
used as an article of food; of this nature are Perguldria edilis, 
Oxystélma esculéntum, Hemidésmus I'ndicus, and some others. 
Synopsis of the genera. 
Trise I. 
OnrHoruuna Miz. Asclepiàdeæ vere, part. R.Br, in mem. 
wern. soc. 1. p. 21. Pollen masses 10, erect (f. 15. d.) or conni- 
vent, smooth, fixed by pairs to the corpuscles of the stigma : 
that is 5 2-celled anthers, separable into 2 parts by a longi- 
tudinal furrow. 
SustRIBE I. SmAPzrnig x. Pollen masses erect (f. 16. d.) or 
connivent, lying on the stigma, fixed by the base or beneath the 
middle of the side. Anthers simple at top, that is, not terminated 
by a membrane. 
§ 1. Column of fructification or gynostegium inclosed. Stami- 
neous corona appendiculate outside. 
Tube of corolla ventricose from the base; 
Stamineous 
1 Crropr'cra. 
limb 5-parted, with ligular, conniving segments. 
corona double; leaflets of the inner corona opposite the lobes 
of the outer one. 
2 Huer’rnia. Corolla campanulate, with a 10-cleft limb: 
having the 5 accessary segments short. Corona double: outer 
one 5-cleft, with bifid segments: inner one of 5 leaflets, altern- 
ating with the segments of the outer one. 
3 Prara’ntuus. Corolla campanulate, 5-cleft; corona sim- 
ple, 5-leaved ; leaflets dentately crested on the back. 
§ 2. Column of fructification, or gynostegium, exserted or semi- 
exserted, appendiculate outside. Pollen masses having one of 
the edges or margins pellucid. 
4 SrAPELIA. Corona double: outer one of 5 undivided 
leaflets, which are usually toothed on the back ; leaflets of the 
inner one opposite the anthers, sometimes obsolete. 
5 Gonoste‘mon. Corona double: outer one of 5 distinct, 
canaliculate, obtuse, mucronate leaflets: of the inner one unci- 
form, obtuse, opposite the anthers, sometimes obsolete. 
6 Popa’ntHxEs. Corona double: outer one 5-parted to the 
middle; the segments channel-formed, rhomboid, deeply emar- 
ginate or bifid: those of the inner form of a reversed foot. 
7 TRIDE'NTEA. Corona double: outer one of 5 tridenti- 
form, distinct leaflets: those of the inner corona unequally bi- 
partite. 
8 Tromérricue. Corona double : outer one 5-parted to the 
base ; with cuneate, rhomboid, or serrated, horizontal segments ; 
leaflets of the inner unequally bipartite; inner branch longer, 
recurved, clavate. Corolla smooth, not wrinkled or corrugated 
as in the other genera separated from Stapélia, ciliated with 
clavate trembling glands. 
9 O'nsza. Corona double : outer one of 5 long, spreading, 
bi-tridentate leaflets ; of the inner unequally bifid, having the 
inner branch longer, incurved, and clavate at apex. Corolla 
