160 



IRIDACE^ 



[Endogexs. 



Fig. CXI. 



spheroidal, angular, oblong, or winged ; albumen horny, or densely fleshy ; embryo 

 inclosed within it, the radicle being miiformly next the hilum. 



Tliis Order differs from that of Amaryllids essentially, m bemg triancU-ous, with the 

 anthers tiu-ned outwards ; from Orchids, to which it approaches nearly m some respects, 

 in not bemg gynandrous ; in the nature of the seeds and placentae, m aU the anthers 

 ° "" being distinct ; from Gingers and Arro\ATOots 



the tlu-ee perfect stamens di^-ide it, indepen- 

 dently of the structm-e of the leaves, which 

 are extremely different. Blood-roots, which 

 are often triandrous mth equitant leaves, 

 have the anthers bm'sting inwardly, and 

 when triandrous theu' stamens are opposite 

 the petals. The Iris represents the general 

 structure of the Order ; but a departure 

 from the form of perianth found m that ge- 

 nus takes place in Crocus, the flower of 

 which is extremely like that of Gethyllis and 

 Oporanthus among Amaryllids on the one 

 hand, and of Colehicum among Melauths on 

 the other ; the latter is kno-wn by their supe- 

 rior triple ovary. The dilated stigma found 

 m Iris is characteristic of only a part of the 

 Order ; in Crocus the stigma is rolled up 

 instead of being spread open, and in many 

 genera it is absolutely thread-shaped. Bro\Mi 

 observes, that Burmannia appears at first 

 sight to agree with Irids, especially in its 

 equitant leaves, colom'ed superior trian- 

 drous perianth, and 3 dilated stigmas ; it 

 cannot, however, be vmited with them, on 

 accomit of its fertile stamens l^eing opposite the inner segments of the perianth, and 

 alternating with an equal number of sterile ones, because of the transverse dehiscence 

 of the anthers, and also the structm'e of the seeds. In Xyvis some resemblance with 

 this Order is discoverable, especially m the disposition of the leaves, the triandrous 

 flowers, and anthers tm-ned outwards ; but that genus is very distinct in its free peri- 

 anth, the outer segments of which are glumaceous, and the mner distinctly petaloid, in 

 the ungues bearing the stamens at theu' apex, in the sterile alternate stamens, and 

 especially in the stmctm-e of the seed. — Prodr. 302. The whole Order is greatly in 

 want of a good critical exammation ; but much caution is requii'ed in formmg the 

 genera, especially in deriving characters from the seeds, for they are both round, and 

 fleshy, and thin, in the genus Iris. 



The Irids are principally natives either of the Cape of Good Hope, or of the 

 middle parts of North America and Europe. A few only are found within the tropics, 

 and the Order is generally far from abundant m South America, if compared with the 

 numbers that exist at the Cape. The genera INIarica and Morsea appear to occupy the 

 same station in hot cUmates that Iris, a closely related genus, does in cooler latitudes. 

 Crocus, among the most conspicuous of the Order, occurs only in Em'ope and Asia. 

 None of the Cape or New Holland forms appear in America. 



More remarkable for then' beautiful fugitive flowers than for their utihty. The 

 rhizome of some of them is shghtly stimulating, as the violet-scented Orris root, the pro- 

 duce of Iris Florentma. Various species of Sisyrinchium, Ferraria, Libertia, and the 

 Irises pseud-acorus, tuberosa, versicolor, and verna, are used as diiu'etics, purgatives, and 

 emetics, but some of them are apt to produce distressing nausea like sea-sickness, with 

 a prosti-ation of sti-ength. The substance called Saffron is the dined stigmas of Crocus 

 sati\Tis ; its colouring ingi-edient is a peculiar principle, to which the name Polychroite 

 has been given ; it possesses the properties of being totally destroyed by the action of 

 the solar rays, of colourmg in small quantity a lai-ge body of water, and of forming blue 

 and green tmts when treated \\-ith sulphuric and nitric acid, or ^\\i^a. sulphate of u'on. 

 In moderate doses this substance stimulates the stomach, and in large quantities excites 

 the vascular system. Moreover it seems to have a specific mfluence on the cerebro-spmal 

 system, as it affects, it is said, the mental faculties, a result which De Candolle considers 

 analogous to that produced by the petals of certam odorous flowers. « In modern prac- 

 tice it is httle used, except as a colom-ing mgredient ; on the Continent it is employed 



Fig. CXI.— 1. Spathe and flowers of RigideUa immaculata; 2. the petals, stamens, &c. of it ; 

 cross section of the capsule of Pardanthus Chinensis ; 4. a perpendicular section of its seeds. 



3. a 



