KEY TO THE GENERA. 
Involucre gamophyllous, calyx-like. 
Involucre 3-parted; fruit lenticular, with lateral 
wings usually armed with teeth...........- 
Involucre 5-parted; fruit oblong, turbinate, or al- 
most spherical, never with toothed wings. 
Fruit with 5 prominent ribs; involucre en- 
larged and membranous in fruit, with 
1 to 3 flowers; perianth usually cam- 
panulate................-..0.2. eee 
Fruit smooth or slightly 5-angled; involucre not 
membranous, usually not enlarged in 
fruit. 
Involucre 1-flowered, campanulate; tube 
of the perianth long and slender... . 
Involucres with 3 or several flowers; peri- 
anth various. 
Involucre rotate, 3-flowered; perianth 
small, short-funnelform, almost 
campanulate..........-------- 
Involucre campanulate or tubular, 
with usually more than 3 flow- 
ers; perianth large, funnelform, 
with a long and conspicuous 
Involucre polyphyllous, consisting of 1 to many small 
bracts, these often deciduous. 
Stigmas linear; inner cotyledon abortive. 
Wings completely encircling the fruit, hyaline, 
membranous; flowers mostly tetramer- 
Wings nct completely encircling the fruit, thick 
and coriaceous or wanting; flowers pen- 
Stigmas spherical or hemispherical; cotyledons 
more or less unlike but neither abortive. 
Flowers in heads, these surrounded by a regu- 
lar many-bracted involucre; stamens 
long-exserted ; fruit turbinate, 10-ribbed. 
Flowers not in heads, each flower with an in- 
volucre of 1 to 3 bracts; fruit various. 
Fruit conspicuously winged.......... eee 
Fruit not winged. 
Fruit asymmetrical, gibbous; inflores- 
cence racemose......---.----- 
Fruit symmetrical, never gibbous; in- 
florescence various. 
Perianth 10 cm. long, with a long 
and very slender tube; 
flowers axillary.....-..-.. 
Perianth smaller, 2 cm. long or 
less, the tube much shorter 
and less conspicuous or 
wanting. 
217 
. WEDELIELLA (p. 218). 
. ALLIONTA (p. 219). 
. MrraBiris (p. 221). 
. ALLIONIELLA (p. 222). 
. QUAMOCLIDION (p. 222). 
. TRIPTEROCALYX (p. 222). 
. ABRONIA (p. 223). 
. NYCTAGINIA (p. 224). 
. SELINOCARPUS (p. 224). 
. CYPHOMERIS (p. 225). 
. ACLEISANTHES (p. 225). 
