1148 AMBROSIACEAE 
villous within. Stamens 5, free, epigynous: filaments distinct. Ovary inferior or nearly 
so, 2-celled or rarely 1-celled : stigma surrounded by a ciliate indusium. Ovules 1 in each 
cavity, or 2 in 1-celled ovaries, erect. Berry with a fleshy exocarp and a bony or woody 
endocarp. 
1. Scaevola Plumiéri Vahl. Perennial, nearly glabrous, more or less shrubby. 
Stem terete, low: leaves alternate ; blades obovate, 4-6 cm. long, entire, narrowed into 
very short winged petioles, or nearly sessile, bearing a tuft of silky hairs in each axil: 
peduncles shorter than the leaves: calyx-lobes much broader than high, rounded: corolla 
glabrous without, about 2.5 cm. long ; tube shorter than the lobes, woolly within, split on 
one side to the base; lobes nearly linear, with broad crisped wings: stamens nearly as long 
as the corolla-tube hanging through the cleft: berry oval, 10-14 mm. long. 
Coast of southern Florida and the Keys, also in the West Indies, South America, Africa and Asia. 
Order 14. CARDUALES. 
Herbs, shrubs or rarely trees. Leaves mainly alternate: blades entire or 
toothed. Flowers perfect, monoecious or dioecious, few or many aggregated on 
a receptacle and surrounded with an involucre of few or many bracts, or the in- 
volucre rarely obsolete. Calyx 1 or 2 rows of bristles, scales, a mere border or 
a crown, or obsolete or wholly wanting. Corolla of several more or less united 
petals. Androecium of usually 5 stamens, the anthers merely converging, or 
united. Gynoecium mostly of 2 united carpels. Ovary inferior. Styles or stig- 
mas mostly 2. Fruit an achene. 
Flowers with tubular corollas, or those of the outer ones prolonged into Hines, 
Stamens distinct, the anthers merely converging about the stigma. am. 1. AMBROSIACEAE. 
Stamens united by the anthers, thus forming a tube around the stigma, ex- 
cept in Kuhnia. Fam. 2. CARDUACEAE. 
Flowers with each corolla prolonged into a ligule. j Fam. 3. CICHORIACEAE. 
FAMILY 1. AMBROSIACEAE Reichb. RAGWEED FAMILY. 
Annual or perennial herbs or rarely shrubby plants, commonly weeds or 
weed-like and either monoecious or dioecious. Leaves alternate, or opposite on 
the lower part of the stem. Flowers very small, in inconspicuous heads, with 
white or greenish disks, the staminate and pistilate in the same heads or in 
separate heads. Involucres of few distinct or united bracts, those subtending the 
pistillate flowers often longer than those of the staminate and usually nut-like or 
bur-like at maturity. Staminate flowers with tubular obconic or funnelform 
corollas; lobes 4-5: stamens usually 5, distinct : anthers merely converging, fur- 
nished with inflexed appendages. Pistillate flowers without a corolla or this 
represented by a mere border or short tube: calyx wanting or a mere border. 
Ovary 1-celled. Stigmas 2, hairy or brush-like at the top. Achene naked si 
enclosed in the accrescent pistillate involucre, which is commonly furnishe 
either with tubercles or spines. 
Stamínate and pistillate flowers in different heads : involucre of the P head bur-like or i 
Braets of the staminate involucres distinct: pistillate involucres bur-like. 1. XAN : 
Bracts of the staminate involucres united. GAERTNERIA. 
Pistillate involucres with numerous prickles in several rows. 2. cala A 
Pistillate involucres with several tubercles or prickles in 1 row. si qa : 
Staminate and pistillate flowers in the same heads. 
1. XÁNTHIUM L. 
Annual or perennial, commonly coarse herbs with upright or diffus 
armed stems. Leaves alternate: blades toothed or lobed, often ample. r ^ 
staminate in terminal spikes, racemes or clusters: pistillate axillary. Staminate involu- 
cres short, of several distinct bracts, in 1-3 rows. Receptacle chaffy, cylindric. pubs 
tubular: lobes 5. Filaments monadelphous. Anthers mucronate, free. Style simp ss 
Pistillate involucres closed, 1-3-beaked, oblong to ovoid, armed with spines, 2-celled. 
Corolla wanting. Stigmas 2. Achenes solitary in each cavity of the involucre. Pappus 
wanting. The plants bloom in summer and fall. CrorBuR. BURWEED, CocKLEBUR. 
e smooth or prickle- 
Heads monoecious : 
