130 CARDUACEAE. 



1. SCAEVOIiA L. Succulent herbs or shrubs. Leaf -blades mostly entire. 

 Flowers irregular, in cymes. Calyx 5-lobed, or obsolete. Corolla-tube open to 

 the base on one side, the lobes winged. Stigma with a ciliate indusium. Berry 

 with a fleshy exocarp. 



1. S. Plumieri Vahl. Plants 3-18 dm. tall: leaf -blades obovate to spatulate, 

 4-6 cm. long: calyx-lobes rounded: corolla white or pinkish, 22-28 mm. long, 

 woolly within; lobes linear to lanceolate: berries oval to globular, 10-14 mm. 

 long, black. 



Coastal sand-dunes, s. pen. Fla. and the F. Keys. (W. I.) 



Order CARDUALES. 



Herbs, shrubs, or rarely trees. Leaves mainly alternate : blades entire, 

 toothed, or divided. Flowers perfect, monoecious, or dioecious, few or 

 many aggregated on a receptacle and surrounded with an involucre, or 

 the involucre rarely obsolete. Calyx one or two rows of bristles, scales, a 

 mere border or crown, or obsolete, or wanting. Corolla of several more 

 or less united petals, or wanting. Androecium of usually 5 stamens, the 

 anthers converging, or united. Gynoecium mostly of 2 united carpels. 

 Ovary inferior. Styles or stimgas mostly 2. Fruit an achene. 



Stamens distinct, the anthers merely converging about the stigma. 



Fam. 1. AMBROSIACEAE. 

 Stamens united by the anthers, thus forming a tube around 



the stigma. Fam. 2. CABDDACEAE. 



FAMILY 1. AMBROSIACEAE. RAGWEED FAMILY. 



Annual or perennial herbs, or shrubs, the plants often coarse. Leaf- 

 blades entire, toothed, lobed, or divided. Flowers in inconspicuous heads, 

 the bracts of the pistillate heads distinct or sometimes united and accres- 

 cent into a bur. Fruit-producing flowers apetalous or with much reduced 

 corollas. Achenes subtended by or enclosed in an involucre. Pappus 

 wanting or obolete. 



1. IVA L. Shrubs with erect stems. Leaf-blades entire or tothed, some- 

 times fleshy. Mature pistillate involucre often nodding. MARSH-ELDER. 



Leaf-blades entire or nearly so : involucres of 6-9 bracts. 1. /. imbricata. 



Leaf-blades coarsely serrate : involucres of 4 or 5 bracts. 2. /. frutesccns. 



:1. I. imbricata Walt. Stems 3-7 dm. long, smooth and glabrous: leaf -blades 

 linear-subulate to linear, 2-5 cm. long, glabrous: involucre 3-4 mm. high: 

 :achenes about 3-3.5 mm. long. 



Coastal region of Fla. (Cont., W. I.) 



'2. I. frutescens L. Stems 8-35 dm. tall, pubescent or puberulent: leaf -blades 

 elliptic, oblong-lanceolate, or oblong-linear, 5-10 cm. long, coarsely serrate: 

 involucres 3.54 mm.; bracts 2-3 mm. long: achenes 2-2.5 mm. long. 



Coastal region, n. and pen. Fla. (Cont.) 



FAMILY 2. CARDUACEAE. THISTLE FAMILY. 



Herbs or rarely shrubs or trees. Flowers borne in heads, the marginal 

 ones commonly differing from the central ones in having a 1-sided, more 

 or less elongate corolla limb. Pappus usually present and often con- 

 spicuous. 



