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XVIII. Descriptions of the Indian Species of Iris. By David Don, Esq., 

 Libr. L.S., Prof. Bat. King's Coll. 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 Iris higlumis of Vahl, I have included in this 

 paper ; the other is from Armenia, and is the Iris reticitlata of the " Flora 

 Taurico-Caucasica" although recorded, apparently on the authority of M. 

 Bélanger, as Iris 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 œconomy, 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 it ; the anthers 

 are directly opposed to the crest, and their cells fac^ outwards. Tlie second 



