820 



IRESINE 



1171. Iresine Lindeni (X %). 



15:1601). In July, 1864, however, Hooker had published 

 it as Iresine Herbstii, in honor of Mr. Herbst, of the Kew 

 Nursery, who introduced it from the River Platte. 

 There are horticultural varieties with Latin names. 



/. Wdllisii, Ort., 



is a small plant, with 



numerous small 

 roundish Ivs., which 

 are bronze - red or 

 dark red above and 

 dark blood-red be- 

 neath. Probably a 

 form of /. Herbstii. 



Lindeni, VanHoutte 

 (Achyrdnthes acumi- 

 nata, Hort.). Fig. 

 1171. Lvs. ovate-acu- 

 minate or lance- 

 ovate, with less arch- 

 ing or curving veins, 

 in the original form 

 rich, deep blood-red, 

 but in some garden 

 forms with light- 

 banded veins. Equa- 

 dor. P.S. 17: 1737.- 

 More pyramidal in 

 habit than the other 

 species, and now 

 more common. To 

 this species evidently 

 belong the garden 

 forms known as Emersoni, Collensii and formosa. 



I. Biemullleri, Haage & Schmidt, is probably a garden form 

 of one of the above. It is a compact, dwarf grower, withstand- 

 ing severe cutting: Ivs. and twigs rose-carmine. L. H. B. 



IEI ARTfi A (after Bernard Iriarte). Palmacece. Tall 

 spineless .palms, with cylindrical or swollen stems sup- 

 ported on a pyramid of aerial roots: Ivs. few, unequally 

 pinnate; Ifts. equilateral, cuneate, entire or erose, pli- 

 cate; petiole channelled; sheath cylindrical: fls. small: 

 fr. 1-2 in. long: stigmas eccentric or lateral in fr. This 

 palm is separated from Ceroxylon by the cuneate leaf- 

 lets. Species 10. Trop. S. Amer. /. Bungerothii was 

 advertised in 1895 by Pitcher & Manda as Triartea, 

 which was presumably a typographical error for Iriartea. 

 No description of this species is available. 



JARED G. SMITH. 



tRIS ( Greek, rainbow). Iridacea?. Plate XVI. Distin- 

 guished from the other members of the tribe except Her- 

 modactylus and Morsea by the 2-winged style branches, 

 from Hermodactylus by the 3-celled capsule, and from 

 Moreea by the more or less connate perianth segments. 

 Herbs with linear or ensiform, equitant leaves and a rhi- 

 zomatous or bulbous rootstalk : stem simple or branched : 

 flowers of 6 segments, the 3 outer reflexed, and the 3 

 inner usually smaller and erect, always narrowed to 

 a distinct claw, one to many in terminal heads, from 

 spathes which are formed of the upper bract-like leaves ; 

 spathe stalked or sessile ; style divided into 3 petal-like 

 branches, which are bind or crested at the tip ; stig- 

 matic surface immediately below the crests : ovary ses- 

 sile or pedicelled, within the spathe. For a monograph 

 of the genus, see Baker's Irideae, 1888. 



About 170 species of Iris are known to botanists. 

 They are natives of the north temperate zone, inhabiting 

 Asia, Europe and North America, with a few species in 

 northern Africa. About 100 species, with innumerable 

 garden varieties, are offered by dealers in America. 

 Many of these, including the native species, are culti- 

 vated only to a slight extent, so that horticultural inter- 

 est centers chiefly around a few groups given below : 



1. German Irises. -The plants known to the trade, 

 and widely advertised as Iris Germanica, German Iris 

 or Fleur-de-lis, are varieties and hybrids of several spe- 

 cies, all of which are closely related to /. Germanica. 

 It is a curious fact that /. Germanica itself has com- 

 paratively few varieties, and forms but a small pai-t of 

 the group named after it. It rarely or never seeds in 

 cultivation, even when placed near closely related spe- 

 cies. The principal parent species are /. Florentines, 



IRIS 



squalens, sambucina, flavescens and variegata. Ow- 

 ing to their diversity of origin, the varieties have a 

 freat diversity of color, ranging from pure white (in 

 . Florentina and its derivatives) through all shades 

 of mauve and blue to dark purple. From /. varie- 

 gata and /. flavescens the yellow-flowered varieties 

 and those whose flowers are variegated with yellow 

 were probably derived. The flowers of all the varie- 

 ties are large and handsome, often stately, exhibiting 

 beautiful variegation and shades of color. They are 

 borne on stout, erect, branched stalks much exceeding 

 the clumps of spreading leaves. All are hardy, and 

 form excellent border plants, flowering in May and June. 



2. Japanese Irises. All the plants cultivated as 

 Japanese Irises are referable to a single species, Iris 

 Icevigata, more generally known as /. Kcempferi. The 

 type of the species has been so much broken that its 

 varieties constitute a distinct horticultural group, con- 

 taining perhaps as many or more named varieties 

 than the 7. Germanica group itself. So far as known, 

 no hybrids or other species enter into the make-up of 

 this class. The plants form strong clumps, attaining a 

 height of 2 to 3 feet, and bearing several flower stems. 

 The leaves are slender, erect, growing almost parallel 

 to each other. In the wild type the inner segments are 

 erect and rather small . Under cultivation they have been 

 much broadened and have acquired a spreading habit 

 giving the flower a flat, expanded form characteristic o 

 this group. In color they range from white through 

 various shades of blue to deep purple, with the seg 

 ments variegated with darker veins and streaks, o 

 plain. All the varieties are hardy, and thrive best in 

 cool, moist situations. They begin flowering in the 

 latter part of June and continue through July. 



3. Dwarf Irises. The dwarf Irises comprise several 

 species related to /. pumila, verna and cristata. They 

 seldom grow over 9 inches high, but spread rapidly by 

 their creeping rhizomes, soon forming large patches. 

 This habit makes them useful border plants. /. are- 

 naria lives well in dry, sandy situations. The flowers 

 are variously colored blue, lilac, yellow, etc. 



4. Oncocyclus Irises. The interesting species of the 

 subgenus Oncocyclus inhabit the dry mountain regions 

 of Palestine, Persia and Armenia. They differ from 

 other Irises in many striking characters. The plants 

 grow from 6 to 12 inches high, the stem bearing a single 

 flower, which in some species is of enormous size, com- 

 pared with the size of the plant. The segments, of 

 which the inner are larger than the outer, present a 

 most singular combination of somber colors. The pecu- 

 liar colors are often due to the interlacing of numerous 

 very thin veins, usually blue or brown, on a white or 

 straw-colored ground. The most common shades thus 

 produced are beautiful sky-blue, light gray, and brown 

 to almost black. In some, all the segments are colored 

 nearly alike, but in most species the inner and oute 

 segments are differently colored. In America this group 

 is not widely cultivated, the most common representa- 

 tive being /. Susiana. Many recorded hybrids have 

 been raised in Europe. For a monograph, see Foster, 

 Gn. 43, pp. 130-135. 



Bulbous Irises. About 20 species of bulbous Irises 

 are cultivated in America. They are rather dwarf, 

 hardy and half-hardy bulbous plants, known chiefly fo 

 the brilliant colors and strong contrasts, and for thei 

 numerous flowers. The species most commonly foun 

 in gardens are /. Xipnium, better known as /. His 

 panica, and /. xiphoides or /. Anglica. The latter 

 probably the oldest Iris in cultivation. See Foster, G 

 C. II. 23, pp. 567 and 726. H . HASSELBKINO. 



The Irises are a widely distributed group of plants 

 occurring in almost all degrees of longitude of the nortl 

 temperate zone. They are found in few forms above 

 40 degrees north latitude, and there seem to be n< 

 species south of the Atlas mountains of Africa, the bota- 

 nists rating the nearly allied southern forms as Moreeas 

 There is a somewhat general localization of some of th< 

 main forms of Irises, central to southern Europe bein 

 rich in the broad-leaved species, bolh tall and dwarf 

 these giving way in Asia to many narrow-leaved forms 

 which forms are also abundant on our western coast, ii 

 fact east to Missouri. Spain and the Mediterranet 



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