784 



HYDKANGEA 



again in spring; this will not injure in any way the pro- 

 fusion of lis. In certain kinds of soil the pink Hortun- 

 sias show a tendency to turn blue, and perhaps this 

 can be caused by adding iron filings or alum to the 

 soil. R. hortensis is also a valuable plant for forcing, 

 and is much grown for Easter, especially the var. Otakua^ 

 on account of its dwarfi-r li.-il.it. IlaTi.lsoiiie ]i.it-|plaiits 

 can be grown in one ycjir trnm luitin--^. In l-'ctnuaiy 



iiMli.;l.r..i.:,uMtm:,' Ii.ium' witli 

 Nlif,'bt botluui beat, and plaiitud 

 in small pots as soon as they 

 are rooted. During the sum- 

 mer they may be easily grown 

 in pots and plunged outdoors 

 in coal ashes or in any kind of 

 porous soil, transplanted sev- 

 eral times and freely watered 

 and occasionally manured ; or 

 they may be planted out in 

 rich soil, exposed to the full 

 sun, where water should be 

 liberally given and now and 

 then an application of liquid 

 manure. Last of September 

 they should be repotted in 8- 

 inch pots, kept shady some 

 days until established, and 

 afterwards exposed to the sun. 

 After the first frosts they may 

 be brought into a cool green- 

 bouse. If intended to have 

 them in flower for Easter, 

 they should be transferred 

 not later than the fore part 

 of January into a warmer 

 house, with a temperature 

 gradually rising from 50° to 

 60°; the plants should be 

 freely watered, and about once 

 a week an application of 

 liquid manure given until the 

 flower buds are developed. The fls. should be almost 

 fully developed some time before they are desired, 

 that they may be hardened off in a cooler house, since 

 overforced plants are likely to collapse if exposed to 

 sudden changes of temperature. After flowering, the 

 plants are pruned and repotted or planted out and 

 treated as above described for cuttings, or they may be 

 thrown away and another set of plants raised from cut- 

 tings. 



B. pet'uilaris is a handsome climbing plant for cover- 

 ing walls and trunks of trees, and grows well in tho 

 shade, but (is. freely only in the full sun. 



The Hydrangeas are readily prop, by cuttings of half- 

 ripened or nearly ripe wood under glass in summer 

 (Fig. 1111); also by hardwood cuttings, layers, suckers 

 or division of older plants. H. querci folia is best propa- 

 gated by suckers or by layers of growing wood put down 

 in summer. Rarely increased by seeds, which are very 

 small, and should be sown in fall in pans or boxes and 

 only slightly covered with soil. 



About 25 species in N. and S. America, Himal. and E. 

 Asia. Lvs. without stipules : fls. perfect in terminal 

 panicles or corymbs, often with sterile marginal fls.; 

 calyx lobes and petals 4-5; stamens usually 10; styles 

 2-5, short: capsule 2-5-celled, dehiscent at the base of 

 the styles, with many minute seeds. 



HYDKANGEA 



A. Erect or spreailing shrubs: stamens 10: petals ex- 



panding. 



B. Inflorescence pyramidal. 



1. panicuUta, Sieb. Shrub or small tree, to 30 ft., 

 with dense globose bead: lvs. elliptic or ovate, acumi- 

 nate, serrate, sparingly pubescent above, more densely 

 on the veins beneath, 2-5 in. : panicle 0-12 in. long: fls. 

 whitish, the sterile ones changing later to purplish ; 

 styles 3: capsule with the calyx about at the middle. 

 Aug., Sept. Japan. S./C. 01. -The following varieties are 

 cult.: \'ar. iloribunda, l{c<;c-l. Panicles large, with more 

 an.l hn-rr M.,,1, ii-. (It. 16:530. Var. grandifldra, 

 •Si.l.. i^:lr. /,..,/-,.,,,. Maxim.). Fig. 1112. Alm.istail 

 tls. st.riir ; i.ani.hs \ irv large and showy. F.S. 

 l():lU05-00. (in. 10:117 and 54, p. 376. R.H. "]87:i:.'-)0. 

 Mn.8:119. A.G.18:313. Ung. 3:357 and 5:3. F.E. 8:214. 

 S.H. 1:174. Var. prSeoox, Rehd. Almost like the type, 

 but flowering about 6 weeks earlier, in the middle of 

 July. G.F. 10:363. The late flowering typical form is 

 sometimes called var. tardlva, Hort. U. pniihiiliiln, 

 var. grandiflora is the common Hydrangea of lawns. It 

 is seen to best efl'ect when planted close in front of heavy 

 shrubbery. Cut back rather heavily in early spring. 



2. quercifdiia, Bartr. Shrub, with spreading branches 

 to ft. : young branches densely f errugineously tomen- 

 tose: lvs. long-petioled, roundish or broadly ovate, pin- 

 nately lobed with serrate lobes, glabrous above at length, 

 whitish tomentose beneath, 4-8 in. long: panicle 4-7 in. 

 long: fls. pinkish white, the sterile ones turning pur- 

 ple. June. Ky. toAlab. and Fla. B.M. 975. Gng. 2:305. 

 Hardy at Philadelphia. 



BB. Inflorescence corymbose, flat or globular. 



c. Cyme without involucre at the base. 



D. Styles u.'iually 2; capsule with the calyr at the 



apex. 



3. arbor^scens, Linn. (H. urticifblia, Hort.). Erect 

 shrub, 4-10 ft.: lvs. long-petioled, ovate, acute or acu- 

 minate, rounded or cordate at the base, serrate, green 

 and glabrous on both sides or somewhat puln-scc'nt or 

 glaucous beneath, 3-6 in. long: cymes 2-5 in. broad, 

 with none or few sterile fls. June, July. N. J. to Iowa, 

 south to Fla. and Mo. B.M. 13:437. -Var. cord^ta, Torr. 

 & Gr., has the lvs. broadly ovate and cordate. -Var. 

 stSrilis, Torr. & Gr. Almost all fls. sterile, known also 

 as Hills of Snow. 



4. radiita, Walt. (H. nlvea, Michx.). SimiKir to the 

 former, but lvs. densely whitish tomentose beneath and 

 cymes always with sterile fls. June, July. N. C. to Mo., 

 south to Ga. B.B. 2:lK.-,.-Var. canSscens, Dipp. (//. 

 f<i»i'.sTCK.s, Hort. n. ri„i-rea,iimM). Lvs. grayisli to- 

 mentose beneath, sometimes pubescent above. Tenn. to 

 Ga.— Hardy about Philadelphia. 



DD. Style 



'.hiT , 



floribni 

 glabrf^i 



5. veatlta, Wall. {IT. heteromdlhi. T1 n n , '^,'s- 

 ceHS, Decne.). Shrub, to 10 ft.: pctii I ' : ' - Md 

 and margined, red: lvs. ovate, acuim v. - 



tosely dentate, almost glabrous abuv,. i„i;>h. 



tomentose beneath, 4-8 in. long : cymu .. b in. hi.iad, 

 with bracts ; sepals of sterile fls. elliptic or obovate, 

 acute or mucronulate: capsule with the calyx above the 

 middle. June, July. Himal. F.S. 4:378-79. G.C. II. 

 22:017. 



var. pubi^srrns, 

 t<i8ft.: petioles 

 noi raargmcMi ; ivs. nvati- or iiiijitip-iivatc to oblong- 

 ovate, acute r,r ac-uiiiir]:ii. . m irat.- witli short callous 

 teeth, more or b-- i i' 

 cymes similar to tli. 

 pals roundish, obtn . 

 middle. July. N.( !,:-:i 

 — Var. glabrSscens, l.'.h 

 DC). Lvs. sniallci-, rlli{. 

 only sparin,i4ly i.uhrsrrnt. 



7. hortensis, Smiili i //. northt.iia,T)C. E.opuMdes, 

 C. Koch. H. Jnpihuni. .Sieb.). Shrub, to 8 ft., almost 

 glabrous : lvs. ovate or ovate-elliptic, acuminate or 

 acute, coarsely serrate, .5-8 in. long: fls. in large cyme* 

 without bracts, white, bluish or pink, few or all of 



math, 3-5 in. long; 

 1 1.1 Her and denser, se- 

 ih the calyx near the 

 . (i.F.3:17and6:396. 

 serrata, Koehue, not 

 coarsely serrate and 



