1682 



IRIS 



IRRIGATION 



greatly in shade; claw conspicuously veined. The 

 common wild form of the Caucasus. Nearly odorless. 

 L.B.C. 19:1829. Gt. 22:779. R.B. 18:60. G.C. II. 

 21:217. Var. caerillea, Hort. Azure-blue. Var. cyanea, 

 Regel. Blue. Gt. 23:797. Var. major, Hort. Like the 

 type, but larger. Gn. 60, p. 198. 



106. Histrio, Reichb. f . (Xiphium Histrio, Hook. f. 7. 

 reticulata var. Histrio, Foster). Plants tufted, slender 

 and flaccid: Ivs. quadrate, with horny edges, deeply 

 grooved on each face, 1 ft. long: st. very short, very 

 slender, 1-fld.: fls. 3 in. diam.; tube 3-4 in. long, blue 

 above; outer segms. obovate-spatulate, spreading, 

 deep blue, with a yellow line in the center bordered 

 with white and spotted and shaded with blue; inner 

 segms. erect, oblanceolate, blue. Feb. Mountains of 

 Palestine. B.M. 6033. Gn. 9, p. 29; 33:558. G.C. III. 

 12:729; 21:105; 45:55. Related to /. reticulata, 

 differing only in its paler, odorless fls., which are pro- 

 duced several weeks earlier. 



107. Vartanii, Foster. Lvs. usually 2, 8-9 in. long, 

 slender, finally longer: st. very short, hidden: tube 2^ 

 in. long; outer segms. with a narrow claw, suddenly 

 enlarged into an ovate-lanceolate blade, pale, slaty 

 lilac, with darker veins and a crisp yellow crest down 

 the claw; inner segms. erect, almost linear-lanceolate, 

 pale lilac. Dec. Palestine, near Nazareth. B.M. 6942. 

 Gn. 77, p. 69. Not scented. 



108. Bakeriana, Foster. Lvs. 3-4, 6-9 in. long, 

 finally a foot or more after flowering, hollow, cylindrical, 

 8-rjbbed: fls. single, on a short peduncle, fragrant; 

 tube 3-6 in.; outer segms. with a long, obovate- 

 elliptical claw, and a small, ovate, reflexed blade, intense 

 violet, creamy in the center, with a yellow streak 

 down the claw; inner segms. shorter, erect, oblan- 

 ceolate, lilac; style-crests large. Feb., March. Arme- 

 nia. B.M. 7084. Gn. 37:462. G.C. III. 7:293; 21: 

 103; 45:53. J.H. III. 34:177; 42:142. G.M. 40:118. 



109. Kolpakowskiana, Regel (Xiphium Kolpakowski- 

 anum, Baker) . Lvs. 5-6, wrapped round by a sheath at 

 the base, very short at the flowering time, but growing 

 longer, linear, channelled, with thickened edges: 

 scape very short, 1-fld.; tube 2-3 in. long; outer segms. 

 with a long, erect claw and an ovate, acute blade, deep 

 violet-purple with a yellow keel down the claw; inner 

 segms. oblanceolate, erect, pale lilac. Mountains of 

 Turkestan. B.M. 6489. Gn. 17, p. 75; 33:558. Gt. 

 1878:939. Very near I. reticulata, fls. at the same time, 

 and is sweet-scented. 



SUBGENUS GYNANDRIHIS. 



110. Sisyrinchium, Linn. (Morsea Sisyrinchium, Ker. 

 Xiphium Sisyrinchium, Baker. 7. maricmdes, Regel). 

 St. 6-12 in. high, stout or flexuous, 1-3-headed: Ivs. 2, 

 slender, as long as the st.: fls. fugitive, lilac-purple, 

 with a yellow, oblong spot on the outer segms. which 

 are oblong-spatulate; inner segms. narrow-lanceolate, 

 erect, pale; style-crests large, lance-deltoid. Widely 

 spread through S. Eu., Afr. and Asia. B.M. 1407 (net 

 good), and 6096. Easily killed by frost. In 7. mari- 

 coides, Regel, the filaments are said to be distinct from 

 each other and from the style. 



Of some of the names, found in catalogues, no complete descrip- 

 tion is available: 7. Amas, Hort. Germanica group. I. angiis- 

 tina. Deep yellow, marked with maroon. Garden form of I. varie- 

 gata. I. angustlssima, Hort. Fls. dark purple. 7. brachysiphon. 

 Pale blue. Rhizomatous. 7. britdnnica. Pale pink, with the outer 

 segms. veined with purple. Garden form of I. squalens. I. Brook- 

 siana, Hort. Mauve-purple. I. cand.id.na. Outer segms. reddish 



?urple; inner segms. light lavender. Germanica. I.coreana. Like 

 . sibirica, early and a free bloomer. 7. edina. Light purple and 



7. Gudldii, Hort. 7. ignitUia, probably Ignacite, a form of I. 

 neglecta. Lilac, with the outer segms. shaded purple. I. ligularis. 

 Purple. Germanica. 7. macrdntha, Hort. Germanica. 7. 

 nlgricans. Lvs. short ensiform: fls. dull black to deep black. 

 Distinct from I. atropurpurea by its uniform dark color and dwarf 

 foliage. Oncocyclus. 7. pdncrea, probably pancrace, var. of I. 



variegata. Buff and purple. 7. Robinsoniana, F. Muell.=Morsea 

 Robinsoniana. 7. Riidinii, Hort., Herb. Fls. black-brown and 

 claret. Said to be stronger and more free-flowering than the other 

 oncocyclus irises. I. tuberdsa, Linn.=Hermodactylus tuberosus. 

 I. Vogeliana. Similar to I. persica and I. Rosenbachiana, but 

 earlier-flowering. Fls. variable in color, silver-gray predominating, 

 with violet, rose or lilac markings. Var. grandifldra. Large-flowering. 



The following are garden hybrids, sometimes cult. : 7. interregna 

 =1. germanica X I. pumila. Several color vars., pale yellow, citron, 

 lavender, and claret-red: fl.-sts. 18 in. high, holding the fls. well 

 above the Ivs. 7. monspur, Foster=I. Monnieri x I. spuria. Said 

 to be very ornamental. 7. ochro-aitrea or ochaiirea, Foster=I. 

 orientalis X I. aurea. Outer segms. rich yellow with a cream-colored 

 border; inner segms. erect, yellowish, bilobed at the apex. 5 ft. 

 7. pdravar or 7. pdrvar, Foster=I. paradoxaxl. variegata. 

 Sts. 2-fld. : fls. dark purple with the bases of the segms. pale brown 

 with darker markings. G.C. III. 29:398. 7. sindpers, Van Tuber- 

 gen=I. sindjarensis X I. persica. Intermediate between the parents 

 in foliage and general habit. Free-flowering: fls. blue like those of 

 I. sindjarensis but lacking the conspicuous patch at the apex of the 

 outer segms. 



The following species are sometimes cult: 7. gracilipes, Gray. 

 Rootstock slender, wide-creeping: Ivs. finally 1 ft. long, }^in. 

 broad: st. 8-10 in. high, forked once or twice: spathes of a single, 

 membranous, scarious valve which reaches about the top of the 

 tube, 1-fld.: fls. purple or lilac; outer segms. obovate-cuneate, 

 deeply emarginate, about 1 in. long, white in the middle, veined 

 with purple and bearing a yellow crest; inner segms. oblanceolate 

 emarginate, smaller, uniformly colored. Japan. B.M. 7926. A 

 small pretty iris of the Evansia group. 7. Piirdyi, Eastwood. 

 Rootstock thin and wiry: Ivs. 1 ft. long and \i~V-ivn.. wide, thick, 

 sub-erect: st. 4-6 in. long, entirely covered by the short inflated 

 bracts: spathe-valves l%-2 in. long, inflated, the outer slightly 

 keeled: fls. pale straw-yellow; tube 1/4-1 H in. long; outer segms. 

 broadly lanceolate, veined with brownish purple; inner segms. lan- 

 ceolate, spreading, faintly veined. Gt. 35: 1222 (as I. Douglasiana). 

 An iris of the apogon group closely related to I. bracteata from 

 which it differs by the long linear perianth-tube. I. tenuis, Wats. 

 Rootstock slender, wide-creeping: Ivs. thin, ensiform, 1 ft. long, 

 yi\n. broad: st. equaling the Ivs., branched: spathe-valves scarious, 

 1 in. long, 1-fld. : outer segms. oblong-spatulate, white, yellow at the 

 throat and marked with purple veins; inner segms. smaller, erect, 

 emarginate. Ore. G.F. 1:6. Apogon. Rare, found only in Ore., 

 and not in cult, except possibly in collections. 



Two Chinese species recently offered in England are 7. BwZ- 

 leyana, Dykes. Foliage grass-like: fls. described as of pretty form 

 though not striking, deep blue; standards blue-purple and falls 

 mottled with same color on creamy ground. 7. Forrestii, Dykes. 

 Lvs. grassy, linear, 12 in., glaucous beneath: sts. numerous, about 

 12 in.: spathes green, with 1 or 2 fls.: falls with veins of dark red 

 or purple-brown; blade drooping, pale lemon-yellow, sometimes 

 with purplish veins. G.C. III. 47:418. 



HEINRICH HASSELBRING. 



IRONWOOD: Usually Ostrya virginica; in S. Calif., Lyono- 

 thamnus floribundus; in Ariz. Olneya Tesota; in Texas, Bumelia 

 lycioides. Many hardwooded plants bear this name. 



IRRIGATION. Irrigation in its broadest sense 

 includes all problems of collecting, storing, delivering, 

 and applying water to the land through the construc- 

 tion of dams, reservoirs, canals and laterals, and the 

 application of power when necessary to deliver the 

 water; while in a restricted horticultural sense it is a 

 method of cultivation, having for its object to increase 

 and regulate the water-supply in the soil. 



In this latter sense, irrigation is a necessary practice 

 in the arid regions, and is advisable in the humid 

 regions in proportion to the intensity of the cultivation 

 and the value of the crop grown. Thus in Florida, with 

 an average of 60 to 70 inches of annual rainfall usually 

 well distributed irrigation has been largely introduced 

 in the past few years for horticultural crops and even 

 for tobacco, as an insurance against loss or damage by 

 the occasional droughts. The first cost of a small irri- 

 gation plant in Florida, for 20 acres or over, is said to 

 be approximately $100 to $150 an acre; the interest on 

 which, and the necessary repairs, would amount to 

 $5 to $10 an acre each year. This is a small expendi- 

 ture to insure a crop against loss or injury where the 

 value to the acre is so great as in many horticultural 

 lines. Irrigation is needed not only to prevent the 

 actual death of the plants, but to promote a uniform, 

 rapid, and continuous growth, which is necessary for 

 the development of the finest texture or flavor of the 

 commercial crop. 



King has shown that the value of a crop saved in 

 Wisconsin, such as the strawberry, in a season when the 

 crops generally are injured by drought, may pay all 

 the expenses of the original cost of the irrigation 

 plant. 



