344 JPHIGENIA 



Iphigenia Kunth. Liliaceae (i). 8 S. Aft. and Madag. to N.Z. 



IpMona Cass. Compositae (4). 10 S. Afr. to Turkestan. 



Ipnum Phil. (Diplachne p.p. EP.}. Gramineae (10). i temp. S. Am. 



Ipomoea L. (BH. incl. Aniseia, Batatas, Calonyction and Exogonium of 

 Choisy, Mitta Cerv., Operculina Silva Manso, Pharbitis Choisy, and 

 Quanwdit Moench.). Convolvulaceae (i. 4). 310 trop. and warm 

 temp., chiefly climbing herbs or shrubs; many cult. orn. fls. (e.g. I. 

 p2irpurea Roth, the morning glory). /. biloba Forst. is a char, creeping 

 pi. of trop. beaches. /. Batatas Lam. (B. ednlis Choisy) is the sweet 

 potato, largely cultivated in warm countries for its tubers, which are 

 used like potatoes. /. (Exogonium) Purga Hayne is the jalap ; its 

 rhizome gives off turnip-like roots about the size of apples. Worm- 

 eaten tubers are most valuable, as the non-resinous parts are eaten. 



Ipomopsis Michx. = Gilia Ruiz et Pav. p.p. (Polemon.). 



Ipsea Lindl. (Pachystoma BH.). Orchidaceae (n. 9). 3 trop. Afr. 

 and As. 



Ir6 rubber, Funtumia elastica Stapf. 



Iresine P. Br. Amarantaceae (3). 25 Am., Afr. 



Iriartea Ruiz et Pav. Palmae (iv. i). 10 trop. S. Am. The stem is 

 supported on aerial roots (cf. Pandanus). Some of the branches of 

 these roots are thorny (cf. Acanthorhiza). In /. ventricosa Mart. 

 (Paxiuba palm), the stem has a peculiar egg-like thickening about 

 half-way up (cf. Bombacaceae, Jatropha). 



Iriartella H. Wendl. (Iriartea p.p. EP.}. Palmaceae (iv. i). i 

 Amazon. 



Iridaceae (EP., BH.). Monocotyledons (Liliiflorae ; Epigynae BH.). 

 57 gen., 800 sp. trop. and temp.; the chief centres of distr. S. Afr. 

 and trop. Am. Chiefly herbs with a sympodial tuber or rhizome below 

 ground. L. usu. equitant in two ranks. Infl. term., cymose (i fl. 

 only in Crocoideae). Fl. ?, reg. or -|-. P 3 + 3, petaloid, united 

 below into a long or short tube; A 3 (the outer whorl), with extr. 

 anthers; G (3), 3-loc., with axile plac. (rarely i-loc. with parietal 

 plac.); style usu. trifid and frequently petaloid. Ovules usu. oo , 

 anatr. "Loculic. caps. Embryo small, in hard endosp. 

 Classification and chief genera (after Pax) : 



I. CROCOIDEAE (fl. solitary, or several developed centri- 

 fugally round a central one; plant small; 1. not exactly 

 in \ phyllotaxy) : Crocus, Romulea. 



II. IRIDOIDEAE (fls. numerous, in spathes, several in each, 

 usu. reg.; stem distinct; 1. equitant): Iris, Moraea, Ti- 

 gridia, Sisyrinchium. 



III. IXIOIDEAE (similar, but spathes i -flowered; fl. often 

 zygomorphic) : Ixia, Tritonia, Gladiolus, Freesia. 



Irideae (BH.) = Iridaceae. 



Iris Tourn. ex L. Iridaceae (n). 125 N. temp. 2 in Brit., /. Pseu- 

 dacorus L., the yellow flag, and I.foetidissima L , the gladdon. Many 

 cult. orn. fl. Most have a sympodial rhiz. with equitant isobilat. 1., 

 and small cymes of fls. in spathes. P petaloid, the sepals usu. bending 

 downwards at the outer ends; opp. to them and almost resting on 

 them are the petaloid styles, under which are the sta. with their extr. 

 anthers. Just above the anther, on the outer side of the style, is a 



