548 ARBORETUM ET FRUTICETUM BRITANNICUM. 



GENUS III. 



PVA L. THE IVA. Lin Svst. Syngenesia Necessaria. 



Identification. Lin. Gen. PL, 1429. ; AH. Hort. Kew., ed. 2., vol. 5. p 181. 

 Derivation. Uncertain. Perhaps from Yua, a name used by the elder botanists. 



Gen. Char., fyc. Flowers monoecious, 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 paleae. Styles on the female flowers subulate, exserted, rather hispid ; 

 those of the males shorter, and thickened at top. Achenia of the disk 

 abortive, those of the ray a little compressed, naked, but furnished with 

 horns. (G. Don.) 



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 monoecious flowers. Indigenous 

 in North America, on the banks of rh 

 species in British gardens. 



j 1. /. FRUTE'SCENS L. The shrubby Iva. 



Identification. Lin. Amcen. Ac., 3. p. 25. ; Willd. Sp. PL, 3. p. 2387. ; Pursh 



Sept., 2. p. 580. 

 Synonymes. ^gerato afflnis peruviana frutescens Phtk. Aim. 12. t. 27. f. 1. ; 



Bastard Jesuits' Bark Tree 

 Engravings. Pluk. Aim., 12. t. 27. f. 1 . ; and our fig. 1020. 



Spec. Char., fyc. 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. Flo-wers 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 Pva frutescens 



can, however, hardly be considered a truly ligneous plant. 



rivers. There is only one shrubby 



1020 /. frut^sc* 



GENUS IV. 



SANTOLFNA Tourn. THE SANTOLINA, or LAVENDER COTTON. Lin. Syst. 

 Syngenesia ^Equalis. 



Identification. Tourn., t. 260. ; Lin. Gen. PL, 1278. ; Less. Syn. Gen. Compos., p. 259. 



Synonymes. Santoline, Fr. ; Heiligenpflanze, Ger. ; Santolina, Ital. 



Derivation. From sanctus, holy, and linum, flax ; so called from its supposed medical qualities. 



Gen. Char. y $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 palea3. Involucrum usually campanulate, with im- 

 bricate adpressed scales. Tube of corolla usually produced at the base 



