688 



H & R T I C U L T U R E, 



May 25, 1907 



THE IRIS. 



(Read Before the Massachusetts Horticul- 

 tural Society by J. Woodward Manning. 



{Cottlitt7iEe /ro»i page t)2l) 



The Dwarf German Irises. 



We now arrive at a point wtiere it is 

 impossible to malce a distinct liorti- 

 cultural line between classes based on 

 botanical classification, but by divid- 

 ing the remaining classes and. groups 

 into those with and without surface 

 rhizomes it is possible to make a form 

 of subdivision. 



The surface rhizomed forms are 

 more popularly Itnown as German 

 Irises, though the true Iris Germanica 

 is but one of many species. The dwarf 

 forms are greatly neglected, being but 

 seldom seen in American gardens, yet 

 possessing great merit in their range 

 of bloom and the earliness of flower- 

 ing period. Iris pumilla is better 

 known than the other species, and 

 growing about nine inches high bears 

 in April showy flowers of deep purple 

 in profusion. As an edging plant it 

 has much merit, and there are various 

 selected varieties ranging from pearly 

 white, through clear blues to the deep- 

 er colored typical form. Iris pumilla 

 is certainly worthy of far greater use 

 than has been the case in the past. 

 I. verna, another dwarf species from 

 the Carolinas, is equally dwarf, quite 

 prolific in bloom with purple shades 

 and blooms about the same time. This 

 does not show the improvement and 

 fixed forms, however, that is true with 

 the last species. The gem among 

 dwarf Irises, however, is the crested 

 Iris cristata, only growing about six 

 inches high, with light green foliage. 

 It forms a carpet of verdure and bears 

 freely of light blue flowers beautifully 

 blotched with golden yellow. I know 

 no form of dwarf Iris with as great 

 adaptability of uses as this, either for 

 naturalizing or for varied garden 

 usage. 



Commonly confounded with Iris 

 pumilla is a form with flowers .borne 

 singly on the stalk, somewhat broader 

 leaves. This is Iris Chamaeiris, or its 

 variety Olbiensis or Italica. The type 

 bears yellow flowers with the falls 

 veined with purple. 



Another small and showy dwarf spe- 

 cies known as Iris flavissima or Blou- 

 dovil, a native of Siberia, bears showy 

 pure yellow flowers. While there are 

 a number of other dwarf species, they 

 have no particular horticultural merit 

 over these. 



New Races and Crossings. 



Intermediate between these dwarf 

 Iris and the taller growing German 

 Iris has appeared a new race within 

 a few years under the name of Alpine 

 Iris, these being produced by Mr. W. 

 J. Caparne of Rohais, Guernsey. These 

 are the result of crossing many of the 

 dwarf species with taller growing 

 kinds; the progeny vary in stature and 

 are claimed to give flowers over a peri- 

 od of six to nine months. Probably, 

 however, this refers to a collection of 

 hybrids rather than any single variety. 

 Undoubtedly they have much of inter- 

 est, and trial will eventually prove 

 such merit and distinction as they may 

 possess. 



For perfect hardihood, freedom of 

 bloom and range of color we can with 

 the dwarf and taller growing German 

 Irises feel quite independent of the 

 more difficult forms, however. The 

 German Iris, as popularly known, va- 



ries in growth in the varied forms 

 from fifteen to forty inches. The ear- 

 lier varieties commence blooming In 

 early May, and by a careful selection 

 of kinds it is possible to keep up a 

 succession of flowers until late June. 



Many species are responsible for the 

 beauty of the class, and their crossing 

 and selection have confused their ori- 

 gin. Iris variegata shows its influence 

 in the prevailing yellow color of the 

 standards of the following varieties 

 with the rather remarkable exception 

 of the Innocenza, a very fine form, 

 pure white throughout. Beacons- 

 field, standards yellow, falls crimson, 

 edged with primrose; Gracchus, stand- 

 ards yellow, falls crimson reticulated 

 with white; Maori King, standards yel- 

 low, falls rich velvety crimson mar- 

 gined with gold; Sans Souci, standards 

 yellow, falls yellow, reticulated with 

 crimson brown; and Regina, standards 

 yellow, falls white, conspicuously 

 veined lilac and edged with primrose 

 yellow. 



Iris sambucina crossed with I. pal- 

 lida has given us the very beautiful 

 variety Madam Chereau, while the 

 cross between variegata and sambu- 

 cina produces Iris neglecta by selec- 

 tion from which we have Clarissima 

 with lavender standards and falls re- 

 ticulated with crimson purple on a 

 white ground. Cythere, standards lav- 

 ender blue, falls clear blue. Florence 

 Barr, v/ith both falls and standards 

 bluish, with rosy lilac tinge, and Mons 

 de Siblc. with lilac standards and deep 

 crimson purple falls. 



Other Beautiful , Forms. 



Some beautiful forms are embraced 

 under the doubtful species hybrida, all 

 with white standards, of which Due 

 de Nemours, with purple edged white 

 falls, George Thorbeck, falls rich vio- 

 let purple veined with white at base, 

 Mrs. George Darwin, falls white, the 

 upper part veined with gold and violet, 

 are among the best. 



The species Iris Germanica is un- 

 doubtedly more common than any oth- 

 er type, particularly in the older gar- 

 dens. In this purple is the predomi- 

 nating color, of which Purple King and 

 Black Prince are the best representa- 

 tives. 



Iris Florentina, the orris root of 

 commerce, is one of the most popular, 

 and very deservedly so, for over a hun- 

 dred years it has occupied a conspicu- 

 ous position in every large New Eng- 

 land garden, and during the period has 

 lost none of its popularity. Free 

 blooming, with flowers of pearly white- 

 ness, it annually leads the way to the 

 charms of the early summer garden 

 flowers. There are three forms, the 

 common type just described, the va- 

 riety Albicans, "of a purer white, and 

 Princess of Wales, even more flori- 

 ferous. with slightly longer- flowers 

 and the most deliciously fragrant of 

 any German Iris. 



The crowning beauty of all German 

 Irises is traceable to the blood of Iris 

 pallida, the broadest leaved of all, with 

 its sword-like foliage often attaining 

 a height of two and one-half feet and 

 an inch and a half across the blade. 

 The flowers are borne on long stems 

 bearing these flowers well above the 

 foliage, altogether producing a most 

 charming effect. The variety Dalma- 

 tica, or sometimes known as Princess 

 Beatrice and occasionally in this coun- 

 try as Madam Almyra, is the finest, 

 with immense flowers of a rich laven- 



der blue and with a charming though 

 subtle fragrance. Delicata is of weak- 

 er growth with falls lavender, shading 

 to white and French gray standards. 

 Hybridizing has not improved this spe- 

 cies, as seen in the variety Queen of 

 May, which, while beautiful, with its 

 soft, rosy lilac, almost pink flowers, 

 is a comparatively weak grower, 

 though floriferous. The beautiful cross 

 of the species with Iris sambucina 

 shown in the variety Madam Chereau 

 is an exception, however, and this is 

 a most delightful flower, with its pure 

 white petals richly feathered with 

 lilac. 



The varieties of German Iris men- 

 tioned are but a fraction of those that 

 can be purchased from horticultural 

 sources; they represent, however, the 

 best, and among them are varieties far 

 advanced in horticultural merit over 

 many of the more common varieties 

 seen. Of clear yellow German Irises 

 we have two species, flavescens and 

 aurea; both are good, the former at- 

 taining a height of three feet, with 

 lemon yellow flowers^ and the latter 

 of dwarfer growth, with rich golden 

 yellow flowers. 



Cultivation of the Surface Rhizomed 

 Forms. 



All of these irises with surface 

 rhizomes are of the easiest cultivation, 

 thriving in ordinary garden soils, re- 

 quiring subdivision and replanting in 

 re-enriched soils as their clumps be- 

 come large or the soil becomes ex- 

 hausted. This replanting should be 

 done as soon as the foliage shows 

 signs of ripening and must not be de- 

 layed so long that they may not be- 

 come thoroughly re-established in the 

 soil before winter. In planting it is 

 better not to sink the rhizomes over 

 an inch below the surface unless the 

 situation is naturally a very dry one. 

 As the plants become established, the 

 rhizome soon assumes its proper ele- 

 vation. Until of late few dise^es 

 troubled this class. Unfortunately, 

 however, a seemingly microbic rot Is 

 found to affect the roots so that the 

 foliage becomes detached from the 

 rhizome. The disease is little under- 

 stood and no remedy has been proved 

 effective, though it is quite jwssible 

 that over richness of soil may serve 

 to foster the disease. 



The Jacob's Sword (Iris Pseud-acc- 

 rus) occupies an intermediate position, 

 never being classed as a German iris. 

 It is a beautiful plant to associate 

 along water courses, and yet will 

 thrive admirably in ordinary garden 

 soils; with ample dark-green foliage 

 it makes a vigorous and healthy clump 

 and bears abundantly of rich golden 

 yellow flowers with a conspicuous 

 orange zone on the base of the falls. 

 Two types are common, one with nar- 

 rower petals than the other. The 

 Gladwin, or Roast-Beef plant (Iris 

 foetidissima), while pale blue in its 

 typical form, in its variety citrina Is 

 of a clear yellow, but the main interest 

 in this centres in the ornamental ef- 

 fect of the bursting seedpods within 

 which the fleshy bright orange-colored 

 seed show to advantage. 



Irises with Tufted Roots. 



Those irises with so-called tufted 

 roots are represented familiarly by the 



Siberian and Japanese classes. The 



Siberian has a number of distinct 

 forms of which the type forms a tall 

 leafy plant four to five feet high with 



