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XVIII. Descriptions of the h d i a n Species of Iris. By DAVID DON, Esq., Libr. L.S., Prof. Bot. King’s CoZZ. Lond.

Read December 18th. 1838.

1 AM indebted to my friend and colleague Dr. Royle for the opportunity of presenting to the Linnean Society the following account of several interesting species of the beautiful genus Iris, derived from materials collected by him during his sojourn in the countries forming the north-west boundary of Bri- tish India. Dr. Royle’s collection contains four species of this genus, one of which is entirely new, the other three being identical with those in the Wal- lichian Herbarium, which besides comprises two additional species : one of them, gathered in Ladak by that enterprising traveller, the late Mr. Moor- croft, and closely related to the Zris bigZunzis of Vahl, I have included in tbis paper; the other is from Armenia, and is the Zris reticulata of the “Flora Taurico-Caucasica,” although recorded, apparently on the authority of M. Relanger, as Zris persica in Wallich’s Catalogue. The number of species therefore actually belonging to the Indian Flora is five.

The species of this genus naturally divide themselves into two groups, which are characterized by certain differences in their structure and economy, and in some degree by their geographical distribution. The first group have sca- riose spathes, a distinct tube, the sepals bearded, and the petals broader, and overlapping each other at their extremities. To this group belongs the far greater part of the European species, which are also remarkable for being early-flowering, the broad convergent petals serving to protect the stamens and pistil from the effects of the weather during the period of their blossom- ing, and the bearded crest of the sepals is doubtless for the purpose of brush- ing out and retaining the pollen until taken up by the recurved stigmas, whose absorbing apices are brought into close contact with i t ; the anthers are directly opposed to the crest, and their cells face outwards. The second

310 Prof. DON'S Descriptions of the h c l i t r n Species of Iris.

group, which is principally confined to Asia and America, is distinguished by having the spathes frequently leafy, a tube continuous with the ovarium, and often very short ; by their beardless sepals ; and by the petals being smaller and spreading. The species of this group produce their flowers generally later in the season ; a circumstance which, together with their being chiefly inha- bitants of a drier climate, renders the protection of the petals less necessary. Our own Flora affords two examples of this section in h i s fadidissirnu and Pseudacorzcs. The very early period of flowering of the Iris fRtidissirna may be supposed to afford a strong objection to the theory as to the use of the con- vergent petals in the first group of the genus ; b u t the plant is well known to occur only in sheltered situations, where a considerable degree of protection is afforded to the flowers. Of the five Indian species, which I shall now pro- ceed to describe, two belong to the first group, and three to the second.

Sect. 1 . EUIRIS.

Perianthii tubus distinctus, subinfundibuliformis. Sepala recurvata, barbata. Spathe p e r s q h

1 .. I. nepulensis, barbata ; scapo tereti Itievi plurifloro foliis ensiformibus ple- rumque longiore, spathis vix foliaceis subaequalibus, sepalis omnibus emar- ginatis, ovario obtush tcigoho perianthii tubi infundibuliformis vix longi- tudine.

Iris nepalensis. Wall.Cut. n. 5050. Lindl. i.rz Bot. Reg. t . 818. Royle Ill. t . 90.

I. japonica. Thunb. in Lima. ?'ram. 2. p . 327 ? I. squalens. Ejusd. Fl. Jnpon. p . 33 ? (3. scapo indiviso subbifloro foliis breviore.

Pet& maxima, invicem apice incunibenti conniventia. scarioso-membranacee.

f. 2.

Habitat in Nepaliae montibus (?Vallich) ; in Emodi montibus Bychuky Ghaut inter Pabur et Tonse, et in Surkunda ad Vicum Bhala Gau. Royle. y . (v. s. sp. in Herbb. Wall. et Royle.)

Rhixoma oblongum, teres, crassum, ramosum, repens, odore gratissimo lridis Jlorentince. Scapus erectus, teres, l=vis, sub flexuosus, fistulosus, g-s-florus, pedalis v. sesquipedalis. Folia ensiformia, acuminata, nervosa, subfal-

Prof. DON'S Descriptions of the Indian Species of Iris. 31 1

cnta, glnuco-viridia, scapo plerumque breviora, unciani et ultrA lata, in- fernk angustata. F h e s fer& omninb I. gerntanicte. SputlzG subquales , lanceolatae, acaininat~e, coiiduplicat,.e, subfoliacez, mnrgine scarioso-mem- liranacez. SepuZa 3 exteriors recurvato-patentia, spathulata, emarginata, violacea, infernk albicanti-vsriegata, barb2 al bB copios9 munita, brevithr unguiculata, elliptico-oblonga, profunclihs emarginata, invice~n se con- vergentia, ~indulata, intensihs colorata, costa prominenti ; omnia praeter ad apicem inargfne integerriina : tubus infundibuliformis, obscurk tri- gonus, vix uncialis. Oi~ i26? i obtush trigonum, 2-unciam longum. Stig- mata (Styli rami) bificla : Zobis conniventibus, acutis, hinc levit8r ser-. r ula t i s .

There can be no doubt that the present species comes very near to Iris ger- nzuizica, and indeed the points which separate them are few, and these not strongly contrasted. That species is, however, distinguished by its shorter scariose and ventricose spathes, entire sepals, longer and slenderer tube, and lastly, by the more coarsely serrated lobes of its stigmas. The rhizoma has the fragrance of that of Iri.sJ7orentitzay and Dr. Royle informs me that it is employed by the natives for similar purposes.

I suspect that this species will prove to be identical with the Irisjuponica, notwithstanding the difference presented by the colour of their flowers, that of Thunberg's plant being described to be white: for I have elsewhere re- inarlted upon the fallacious character .afforded by colour, as a test of specific distinction, not only in this genus, but throughout the greater part, of the Mo- nocotyledonous class, as is beautifully illustrated by the numerous cultivated varieties of li-is Xiplziztnt and Xiphioides. A series of careful experiments are still wanting to determine the exact limits of species in this genus.

The variety p. differs in nothing except in its shorter two-flowered scape, and there are cultivated specimens of nepuknsis from the Calcutta Garden in the Wallichian Herbarium having this depressed character. In my character of the species given in the Proceedings of the Linnean Society, I have described the stem as compressed and furrowed; but these appearances presented by the dried specimens prove to be the mere result of desiccation.

2. I. karnaonensis, barbata ; scapo brevissimo unifloro, tub0 perianthii lon- VOL. XVIIJ. 2 T

312 Prof. DON'S Descriptions of the Indian Species of Iris.

gissimo subfiliformi, sepalis interioribus bilobis long& unguiculatis, ovario turbinato 3-gono.

Iris kamaonensis. WalZ. Cat. fi . 5052. Habitat in Emodi montibus ad Kedarlianta (Royle) ; Bydrunanth. Blinkworth.

3 . Floret Augusto. (v. S. sp. in Herbb. Wall. et Royle.)

Rhizomd repens, nodidoso-rainosum, caespitosuni, supra rudimentis foliorunt fibrosis coronatum, infrd munitum fibris crassiusculis. Scupus erectus, teres, gracilis, uniflorus, brevissimus, vix sesquipollicaris, foliis omninb obvolutus. Folk lineari-ensiformia, apice subadunco acuta, striata, lenta, viridia, 3-6-pollicaria, 2 lineas lata ; exteriora latiora, imperfect& evo- luta, scarioso-membranacea, imbricato-vaginantia. Flos Inagnitudine I.

fEavissirnm. Spathe inzquales, lanceolatae, acutae, conduplicatce, folia- cez, margine angust6 membranaceae ; altero (interiore) breviore. Sepalu sanguinea, maculis atropurpureis notata ; 3 ezteriora recurvata, spathu- lata, levitkr emarginata, barbii copiosii lutescente munita ; 3 interiors (petala) cuneata, long& unguiculata, biloba, conniventia : tubus gracilis, subfiliformis, 2-uncialis et ultra, supern& dilatatus. Ovarium turbinato- oblongum, 3-gonumY 3-costatumY semunciale et ultr8. Stigmata (Styli rami) rosea, divaricate-patentia, apicibus incurvatis, bilohis, lobis inte- gerrimis.

This is a very distinct and beautiful species. The form of its inner sepals, and the great length of the tube of the perianthium, as well as its turbinate ovarium, essentially distinguish it from every other; and indeed there are none with which it can well be contrasted.

The sepals are of a red colour, and elegantly mottled with dark purple spots.

We may hope to see this elegant species shortly introduced to our gardens by means of Dr. Falconer, the able successor of Dr. Royle in the superintend- ence of the Honourable East India Company's botanic garden at Saharunpore, and who, I am happy to learn, is carrying out the observations and experi- ments so happily commenced by that zealous naturalist.

Prof. DON’S Descriptions of the Ilidiatt Species o f Iris. 313

Sect. 2. XIPHIOIDES. Perianthii tubus solidus, cum ovario continuus, permpi: brevissimus. Sepala

imberbia. Petaln angustiora, patentia. Spatha? plerumque foliacece.

3. I. decora, iinberbis ; scapo tereti subtrifloro, foliis lineari-ensiformibus, se- palis submpalibus bilobis recurvis ; exterioribus menibranaceo-cristatis, perianthii tubo filiformi ovario triquetro duplb longiore, stigmatibus dila- tatis serratis conniventibus, seminibus apice carunculatis.

Iris decora. WXl. PI. Asia!. Rar. 1. p. 77. t . 86. I. sulcata. Ejusd. Cat. 11. 5049. I. nepalensis. Don Prodr. Fl. Nepal. p . 54. I. orientalis. 2’hunb. in Linn. Trans. 2. p . 328. ? I. sibirica. Ejusd. Fl. Japon. p . 33.?

Habitat in Nepaliae montibus ad Bempedi et Ekdanta (Wallich) ; in Emodi montibus ad Choor et Punjee. Royle, Blinkmorth. 3 . Floret Maio. (v. s. sp. in Herbb. Wall. et Royle.)

RIiixonta truncatum, grumosum, f e d Hemerocallidis f lave, fibris infern& in- crassatis fusiformibus, suprd rudimentis foliorum emarcidorurn fibrosis copiosk vestituin. Scupus erectus, teres, laevis, flexuosus, fistulosus, sim- pliciusculus, 3- v. rarb 5-florus, spithamaeus, pedalis v. cubitalis. Folia lineari-ensiformia, acuminata, tenuiora, membranacea, nervis prominenti- bus costata, hinc pallidiora, glaucescentia, inde gramineo-viridia, scapi longitudine, 4-5 lineas lata. Flores pulcherrimi. Pedunculi breves, hint convexi, inde plani. Sputhce foliacea, subaequales, lanceolatE, acu- minatE, conduplicatq margine scariosa. sepala omnia spathulata, bi- loba, recurvato-patentia, pallid& lilacha ; exteriora 3 vix majora, pulchr& purpureo-venosa, cristh lineari membranacea serrulath lutescenti 6 basi ad medium usque longitudinalithr coronata : tubus subfiliformis, uncialis, spatbarn superans. Ovarium 3-angulare, tub0 perianthii duplb brevius, Stigmata (Styli rami) ampla, cuneata, bipartita, erecto-conniventia, pal- lid& lilacina, f e d longitudine sepalorum : lobis cuspidatis, hinc margine arguth serratis. Capsula elliptico-oblonga, triquetra, I ~ v i s , utrinque at- tenuata, 3-locularis, 3-valvisY fuscescens, sesquipollicaris, stylo elongato persistenti coronata. Semina in quoque loculo numerosa, crebrk biserialia

2 2 ’ 2

314 Prof. DON'S Descriptions of the h d a n Species of I r i s .

hint convexa, in& biangulata, raplie pallicliori elevat% aucta, apice ap- pendice obtus2 fungo& cai*nnculata, basi lrilo pnr\7o instructs : testa coriacea, I'ugosa, brunnea, el~idei*inick piiIli& fuscA : albumeri co- piosuIn, cartilagineo-carnosu~l~, album. E1tzbryo teres, iiiedio paululhm constrictus, clavatus, albus, extremitate radiculari (cauliculari) ciassiori.

This species departs from the rest of the genus in so many points, that it may safely be ranked with those which, like Iris tuberosa and Sisyriiichiirin, appear to constitute the types of so many distinct sections. The rhizoma is exactly that of Henzerocallis, being furnished with thickened fusiform fleshy fibres, and the leaves are likewise remarkable for the diversity of colour of both surfaces, the inner one being of n bright green, and the outer one glan- cous. The sepals are uniform, hilobecl, and recurved, the outer three being furnished along their centre with a peculiar membranous crest or fold. The stigmas are remarkably broad and connivent. The seeds are fiirnishecl at their apex with a thick, compressed, fungous appendage, resulting from an unusual developnient of the testa a t that point.

This species has been introduced to our collections by Dr. Wallich, and is reiiwkable for the elegance of its habit and the beauty of its flowers.

I have referred under this species Thunberg's Iris orientalis ; but an exarni- nation of authentic specimens is necessary to solve our doubts on this point.

4. I. Zong~~olia, imberbis ; foliis margine scabris, scapo brevissinio unifloro, sepalis sublanceolatis integerrimis, tub0 pei ianthii vix ullo, ovario elon- gato triquetro scapum adc-equante, stigmatis lobis integerriniis.

Iris longifolia. Royle 111. t . 91 ,J 2. Habitat in Cashmeril. Koyle. 3 . (v. s. c. in Herb. Royle.)

Rhixonza repens, oblongum. Scapus uniflorus, gracilis, triangularis, foliis om- ninb obvolutus, 2-3-pollicaris. Folia lineari-ensiformia, acuta, recurvato- falcata, firmiora, coriacea, laevia, viridia, margine praesertirn apicern ver- sus tenuissimk serrulata, bipedalia, ferb semunciam lata. Flos 1. hab- philce. Spathe subaequales, foliaceze, conduplicatz, florem snperantes. Sepala sublanceolata, integerrima, recurvato-patentia, intens& ccerulea ; exteriora 3 duplb majora, jmberbia, infernk albicnntia, purpureo-venosa : tubus vix ullus. stigmata (Styli rami) angustiora, bilsba, recurvato-

Prof, DON'S Descr-iptioru of the lizrlimi Species of Iris. 315

patentia, sepalis interioribus (petalis) breviora et similitkr colorata : lobis ovntis, acutiosculis, integerriinis, divaricatis. Orctri?cnz angustissimum, triquetrurn, +pollicare, s u r s h crassius.

Although this bears a considerable resemblance to Zris halophila, and even tof&;dissima, it is nevertheless essentially different from either ; the extremely short scape, and minutely serrulate leaves, will distinguish it from every other species hitherto recorded of this group.

The specimen in Dr. Royle's Herbarium is a cultivated one, the plant having been raised in the Saharunpore botanic garden from Cashrncre seeds.

5. Z. ~ ~ o o r c r ~ o f t i m a , imberbis ; scapo bifloro pedunculis breviore, spathis glu- maceis tubiim perianthii subaequantibus, sepalis lanceolatis acutiusculis, ovario 6-sulcato.

Iris Moorcroftiana. Wall. Cat. n. 505 I . Habitat in Ludak. Moorcroft. 3 . (v. s. sp. B b. Moorcroft lecta in Herb.

Wall.)

1Clihoma caespitosum, fibris niimerosis filiforinibus ramulosis instructum, et supra folioruni emarcidorum rudimentis scariosis v. fibrosis iinbricatis coronatum. Scapus teres, indivisus, biflorus, pollicaris: foliis omninb im- mersus. Folia stricta, angustk lineari-ensiformia, rigida, nervosa, coria- cea, 4-6-uncialia, vix 2 lineas lata, apice acutiusculo subadunco. Flores pallidk coerulei, pedunculati, pedunculis subfiliformibus, sesqui v. bipolli- caribus. Spathe glumace=, lanceolatae, acutiusculae, convolutae, mar- gine lat& scarioso-membranaceE ; alter3 (exteriore) tubuin perianthii subaequante. Sepalu lanceolata, acutiuscula ; interiorn 3 parhm angus- tiora ; omnia imberbia, integerrima : tubus brevissimus, angustus, 6-sul- catus, aequalis. Ouarium unciale, teretiusculum, 6-su~catum. Stignznta (Styli rami) sepalis interioribus latiora, biloba : lobis inaequilateri-ovatis, acutiusculis, integerrimis.

We have already remarked upon the intimate affinity existing between this species and Iris bigZunzis, discovered by Pallas in Eastern Siberia, and of which there exist two specimens in the 1,innaean Herbarium, which had been com- municated to Linnaeus by that distinguished traveller and naturalist. Of

316

these specimens, as well as of many others sent by Pallas, and which had reached the great Swedish Naturalist towards the close of his earthly career, we find no mention in any of his works ; and it appears from the papers on which they are pasted, that even the charge of placing them into the Herba- rium had been committed to his son.

The chief points of difference between this species and biglumis are its lengthened peduncles and narrower sepals : for in other respects they are so much alike. that, without a very careful examination, the specimens might readily be confounded.

My knowledge of the colour of the flowers of this and the preceding species is derived from a series of very beautiful drawings in the possession of Dr. Royle.

Prof. DON'S Descriptions of the Indian Species of Iris.