286 COMPOSITE. CYCLACHiENA. 



annual; the stem simple and more or less branched at the summit; the 

 leaves opposite, ovate or subcordate, acuminate, doubly or unequally serrate, 

 3-nerved, hirsute-canescent or pubescent beneath, somewhat scabrous, on 

 long petioles. Heads small, greenish, ebracteate, sessile and often glomer- 

 ate, disposed in compound terminal and axillary spikes, forming a pyrami- 

 dal panicle. 



C. xanthiifolia (Fresenius, 1. c.)— Iva xanthifoha, Nutt. ! gen. 2. p. 185. 

 I. (Picrotus) xanthifolia & paniculata, Nutt.! in trans. Amer. phil. soc. {n. 

 ser.) 7. p. 347. 



In alluvial soil, Upper Missouri near Fort Mandan &c., Nuttall ! Prince 

 Neu-xvied (seeds from which the plant was raised in the Frankfort Botanic 

 Garden) to the Rocky Mountains, NutlalL.'— Scales of the involucre some- 

 what hairy externally and ciliate, distinct, as long as the disk. Ovaries 

 minutely somewhat hairy at the summit when young, at length glabrousr; 

 the corolla reduced to a minute ring surrounding the base of the style. — We 

 are not sure that the plant is truly polygamo-dioecious, since the styles, in 

 what Mr. Nuttall considers the sterile p'la'nt, are apparently perfect: the fer- 

 tile ovaries of Iva ciliata are at first very small hkewise : but in this plant 

 the inner involucral scales are also proportionally reduced in size, so as to be 

 readily overlooked, as indeed they have been by Mr. Nuttall. We have a 

 specimen from a plant cultivated in Mr. Lambert's garden, exhibiting the 

 heads in a somewhat monstrous state ; the styles of the fertile flowers fre- 

 quently 3 or 4, and those of the exterior sterile 2-cleft ; the former showing 

 an evident corolla ; the corolla of the disk-flowers 10-nerved ; the receptacle 

 towards the margin furnished with dilated and somewhat cucullate chaff; 

 while in the wild plant the chaff" is often nearly or quite wanting.— Except- 

 ing its entire opposite leaves, this plant has the habit as well as.the inflor- 

 escence and many of the characters of Euphrosyne, DC. [DeLess. ic. 4. t. 

 28 j ; of which, indeed, it might be deemed a section, should that genus 

 prove to have an inner series of involucral scales, similar to that which is re- 

 presented in the figure as one of the paleae of the receptacle. 



78. IVA. Linn. ; Gfertn.fr. t. 164 ,- DC.prodr. b. p. 529. 



Fertile and sterile flowers in the same heads ; the former few (1-5), mar- 

 ginal, with a small tubular corolla ; the latter several (7-20, rarely only 2 or 

 3), with a tubular-campanulate or infundibuliform 5-toothed corolla. Scales 

 of the campanulate or hemispherical involucre 3-5 in a single series, and of- 

 ten more or less united, or 6-9 and imbricated, usually ovate or orbicular 

 and somewhat fleshy. Receptacle small, chaffy ; the chaff linear or spatu- 

 late. Anthers sometimes with a mucronate inflexed appendage, distinct or 

 nearly so. Style in the fertile flowers deeply 2-cleft ; the branches linear or 

 linear-subulate, one of them often imperfect ; in the sterile flowers undivi- 

 ded, usually with the apex radiate-penicillate. Achenia obovoid, somewhat 

 obcompressed, wholly destitute of pappus ; the sterile flowers with rudimen- 

 tary ovaries. — Herbaceous or shrubby commonly maritime (American) 

 plants. Leaves opposite or the upper alternate, often thick or fleshy, 1-3- 

 nerved. Heads solitary or ternate in the axils of the upper leaves, or of fo- 

 liaceous bracts, forming spikes orsjjicate racemes, deflexed. Corolla green- 

 ish-white. Anthers yellow. 



