548 ARBORETUM ET FRUTICETUM BRITANNICUM. 
Genus III. 
I'VAL. Tue Iva. Lin Syst. Syngenésia Necessaria. 
Identification. Lin. Gen. Pl., 1429. ; Ait. Hort. Kew., ed. 2,, vol. 5. p 181. | 
Derivation. Uncertain. Perhaps from Ywa, a name used by the elder botanists. 
Gen. Char., §c. Flowers moncecious, male and female on the same head: 
female ones few on the same head, in a single series around the circum- 
ference, they are tubular or campanulate; the male flowers are numerous 
in the disk, they are tubular and 5-toothed. Involucrum usually 3—5- 
leaved, campanulate. Scales ovate, in one series ; rarely imbricate, with 
3 or 4: series of scales. Receptacle flat, beset with linear or linear spathu- 
late paleze. Styles on the female flowers subulate, exserted, rather hispid ; 
those of the males shorter, and thickened at top. Ackenia of the disk 
abortive, those of the ray a little compressed, naked, but furnished with 
horns. (G. Don.) F 
Leaves simple, opposite, exstipulate, deciduous; lanceolate, serrated. 
Flowers in terminal heads, solitary or three together, constituting a folia- 
ceous terminal raceme.— Suffrutescent deciduous shrubs, with the habit of 
Artemisia, but readily distinguished by the moncecious flowers. Indigenous 
in North America, on the banks of rivers. There is only one shrubby 
species in British gardens. 
a 1. Z. FRuTE’scens L. The shrubby Iva. E 
Identification. Lin. Ameen. Ac., 3. p. 25.; Willd. Sp. Pl., 3. p. 2387.; Pursh 
Sept., 2. p. 580. 
Synonymes. Agérato affinis peruviana frutéscens Pluk. Alm. 12. t. 27. f.1.; . 
Bastard Jesuits’ Bark Tree . 1 
Engravings. Pluk. Alm., 12. t 27, f.1.; and our fig. 1020. 
Spec. Char., §c. Leaves lanceolate, deeply serrated, rough * 
with dots. (Willd.) A suffruticose deciduous bush, of 
little or no beauty in the popular sense of that word. New 
England to Florida, on the sea coast. Height 3 ft. to 4 ft. 
Introduced in 1711. Flowers greenish white; August 
and September. 
In sheltered dry situations it is tolerably hardy; but, when 
freely exposed in moist soil, it is apt to be killed to the 
ground in severe winters, Cuttings. The Z'va frutéscens 
can, however, hardly be considered a truly ligneous plant. ade. Deeeens: 
Genus IV. 
SANTOLI'NA Tourn. Tun Sanrouina, or LavenDEeR Corton. Lin. Syst. 
Syngenésia AEqualis. 
Identification. Tourn., t. 260.; Lin. Gen. Pl., 1278.; Less. Syn. Gen. Compos., p. 2°9. 
Synonymes. Santoline, Fr.; Heiligenpflanze, Ger.; Santolina, Ital. 
Derivation. From sanctus, holy, and linum, flax ; so called from its supposed medical qualities. 
Gen. Char., §c. Heads many-flowered, sometimes homogamous, and some- 
times heterogamous. Flowers-of the ray few ; female, from abortion; some- 
what ligulate. Receptacle.convex, subhemispherical, furnished with oblong 
half-flower-clasping palez. Involucrum usually campanulate, with im- 
bricate adpressed scales. Tube of corolla usually produced at the base 
