IRUP] 



€fyt Erra£urg at 23ntang. 



628 



constitute one series of a flower dissimilar 

 in size or form. 



IRUPE. Victoria regia. 



IRVINGIA. A genus of Simarubacea?, 

 allied to Soulamea and Amaroria, but dif- 

 fering in habit, in the large disk under the 

 ovary, and in several other characters. It 

 consists of tropical African trees, entirely 

 glabrous, with alternate entire leaves con- 

 volute in the bud, and leaving prominent 

 rings on the branches as they fall off. The 

 flowers are small and yellow, in terminal 

 or axillary panicles. The drupaceous fruits 

 of two at least of the three species known 

 are edible, and known under the name of 

 Wild Mangos. 



IS ACANTHUS. A genus of Acanthacece, 

 containing a single species from Africa. It 

 is a branching shrub, with entire leaves, 

 and white flowers in few-flowered termi- 

 nal spikes. The calyx is five-parted, the co- 

 rolla has a slender tube, and a limb consist- 

 ing of a single unequally five-lo'oed lip, and 

 there are four exserted stamens. [W. C] 



ISACHNE. A genus of grasses belong- 

 ing to the tribe Panicece, now included by 

 Steudel in Panicum. [D. M.] 



ISANTHERA. A genus of Gyrtandracece, 

 containing a single species a native of 

 India. It is an herbaceous plant, with an 

 erect stem,obovate-cuneiform acute leaves, 

 and flowers in axillary clusters. The flowers 

 are polygamous. The hermaphrodite ones 

 have a five-cleft calyx, a rotate corolla, four 

 or five stamens, and one-celled ovary. The 

 female flowers want the corolla. This genus 

 has the flowers of Platystemma conjoined 

 to the habit of Cyrtandra. [W. C] 



ISANTHUS. A genus of labiates, hav- 

 ing the calyx bell-shaped, with five equal 

 lobes, enlarging as the fruit ripens; and 

 the corolla slightly longer than the calyx, 

 with five nearly equal lobes. The only 

 species, /. cceruleus, is a small annual, co- 

 vered with clammy hairs, the flowers mi- 

 nute, pale blue. It is a native of the 

 southern parts of the United States, and is 

 called False Pennyroyal. [G. D.] 



ISARIA. An important genus of fila- 

 mentous moulds, connecting them very 

 closely with the lower club-shaped Eyme- 

 nomycetes. The genus is divisible into 

 two distinct groups, in one of which all 

 the species grow upon insects, and prin- 

 cipally upon Hymenoptera. It is, however, 

 suspected that all of these are mere con- 

 ditions of different species of Cordiceps. 

 The species of the second group grow 

 upon various vegetable substances, and a 

 few of these must be considered as mere 

 sporiferous forms of other fungi. Some 

 good species, however, remain, which are 

 known by their threads being compacted 

 with a solid mass, which may be either 

 simple or branched, the free tips of which 

 bear the spores. The limits between some 

 of these and Pistillaria are so indefinite, 

 that it is not always possible to say posi- 



< tively to which genus a species should be 

 referred. [M. J. B.J 



ISARIEI. Anatural order of filamentous 

 moulds containing those genera in which 

 the fertile threads are compacted, and have 

 deciduous pulverulent spores at their free 

 apices. It must be observed, however, 

 that the order contains two sets of species 



i which are connected on the one hand with 

 Mucedines, and on the other hand with 



| Dematiei, in which order the threads are 

 more or less dark and carbonised. Little is 



I known of exotic species. Ceratium, how- 



■ ever, which, from its texture, would per- 

 haps be better referred to Hymenomycctes, 

 occurs in Ceylon, and we have one of the 

 darker series in India. North America, as 



I might be expected, has some in common 

 with Europe, besides an admixture of dis- 

 tinct forms. [M. J. B.] 



I ISATIS. A genus of Cruciferce, consist- 

 ing of erect annual or biennial plants, 

 natives of Southern Europe and "Western 

 Asia, one being found in China. They have 

 undivided leaves, with a bluish bloom, 

 the lower stalked, the upper clasping the 

 stem ; and the small yellow flowers are 

 j borne in long loose erect terminal pani- 

 I cles, and produce flat pendulous pods of 

 an elliptical form, with a strong rib along 

 each side. 

 I. tinctoria, the Dyer's Woad, is said to 

 ! have been originally a native of South- 

 1 eastern Europe, from whenceit has spread 

 I by means of cultivation and become na- 

 i turalised in most parts of Europe as far 

 north as Sweden, and also in some parts of 

 I Asia. It is a biennial, growing from eigh- 

 , teen inches to three or four feet high, 

 j with a smooth straight stem, branched to- 

 wards the top, the root-leaves stalked, in- 

 versely egg-shaped or oblong, and coarsely 

 i toothed, the upper ones narrow lance- 

 shaped, with prominent auricles at the 

 \ base. The pods are rather more than half 

 i an inch long, broad, and very blunt at the 

 ! top, but tapering to the base. 

 I Before the use of indigo became common 

 ! among European dyers, the blue colour- 

 J ing matter called Woad, obtained from 

 this plant, was an article of great import- 

 ance, and the plant was extensively cul- 



■ tivated ; but the introduction of indigo 

 I has almost entirely superseded it, and it is 



now only grown to a limited extent, and 

 used chiefly by woollen dyers for mixing 



I with indigo, in order to excite fermenta- 

 tion. It is generally prepared by grinding 



' the leaves into a paste, which is then care- 



j fully fermented in heaps, and afterwards 

 made into balls or bricks for sale. Small 

 quantities of these balls are annually im- 

 ported from the continent, amounting in 

 1859 to 200 cwt. The use of woad as a 

 dye dates from very early times. Diosco- 

 rides, Pliny, and others, mention its use 

 for dyeing wool ; and Caesar relates that 

 the ancient Britons used it for staining 

 their bodies— the word Britain being de- 

 rived from the Celtic brith or brit, ' painted,' 

 in reference to this custom. 



i J. indigotica is cultivated as a tinctorial 



