3. Iva Imbricata Walt. Sea-Coast Marsh Elder

Fig. 4122. Iva Imbricata Walt. Fl. Car. 232. 1788

Perennial by woody roots, glabrous or nearly so throughout, fleshy; stem 1°-2° high, simple, or sparingly branched. Leaves all but the lowest alternate, sessile, oblong-spatulate, or lanceolate, obtusish, mucronulate, entire, or rarely serrate, obscurely 3-nerved, the larger 1'-2' long, 3"-5" wide; heads about 4" broad, short-peduncled or nearly sessile, the upper often longer than their subtending leaves; involucre broadly campanulate, its bracts 6-9, not united, somewhat imbricated in 2 series; fertile flowers 2-4, their corollas tubular, the staminate ones much more numerous; chaff of the receptacle spatulate.

On sandy sea-shores, southeastern Virginia to Florida and Louisiana. Bahamas; Cuba. July-Oct.

3 Iva Imbricata Walt Sea Coast Marsh Elder 7933 Iva Imbricata Walt Sea Coast Marsh Elder 794

4. Iva Ciliata Willd. Rough Marsh Elder

Fig. 4123

Iva annua Michx. Fl. Bor. Am. 2: 184. 1803. Not L.

Iva ciliata Willd. Sp. Pl. 3.: 2386. 1804.

Annual, hispid-pubescent; stem simple, or branched, 2°-6° high. Leaves nearly all opposite, ovate, petioled, scarcely fleshy, puberulent beneath, acuminate at the apex, abruptly or gradually narrowed at the base, coarsely and irregularly dentate, 3-nerved. the lower 4 -5' long; heads spicate-paniculate, about 1" broad; spikes dense or interrupted, erect, 2'-8' long; upper leaves linear-lanceolate, hispid, squarrose, much longer than the heads; bracts of the involucre 3-5, distinct or united below, hispid; fertile flowers 3-5, their corollas slender; staminate flowers 10-15.

In moist soil, Illinois to Nebraska, south to Louisiana and New Mexico. Plant with the aspect of an Ambrosia. Aug.-Oct.

5. Iva Xanthiifolia Nutt. Burweed Marsh Elder

Fig. 4124

Iva xanthiifolia Nutt. Gen. 2: 185. 1818.

Cyclachaena xanthiifolia Fresen. Ind. Sem. Hort. Franc. 4. 1836.

Annual; stem much branched, pubescent or puberulent above, glabrous below, 3°-6° high. Leaves nearly all opposite, broadly ovate, long-petioled, acuminate at the apex, abruptly or gradually contracted at the base, coarsely and irregularly dentate, pale and canescent or puberulent beneath, roughish above, 3-ribbed, the lower often 6' long and wide; inflorescence spicate-paniculate, terminal and axillary, ample, naked; heads sessile or minutely peduncled, 1" broad or less; bracts of the involucre in 2 series of 5, the outer ovate, the inner obovate or truncate, concave, subtending the usually 5 achenes; corollas of the fertile flowers rudimentary or none; staminate flowers 10-15,their corollas obconic.

In moist soil, or sometimes in waste places, Ontario to Assiniboia, south to Wisconsin, Nebraska, New Mexico and Utah. In waste grounds farther east. Plant with the aspect of a Cheno-podium. July-Sept.

5 Iva Xanthiifolia Nutt Burweed Marsh Elder 795