i connected by the long crest •which sur- 

 | mounts their lobes. The fruit is succulent, 

 i surrounded by the persistent outer whorls 

 i of the flower, either one or two-celled. 

 ; From other genera this differs in its nearly 

 regular flowers, and in its five stamens 

 • which are united into a tube, having at 

 : their base scale-like appendages prolonged 

 ! beyond the anthers. [M. T. M.] 



I HYMEXIDIUM. A genus of umbellifers, 

 I distinguished chiefly by each half of the 



fruit being provided with five ridges pro- 

 [ longed into wing-like membranes. The 



genus comprehends herbaceous plants na- 

 I tives of Kashmir, having the leaves much 



divided, and membranous bracts longer 

 I than the flowers. [G. D.] 



HYMEXIUM. The fructifying surface 



in Fungi, more properly applied where the 

 I spores are naked, but used also to express 

 j the same condition in such genera as Hel- 

 j villa and Peziza. It is not used where the 

 j fructifying cells are contained in a distinct 

 , perithecium, the word nucleus being then 

 . more generally substituted. [M. J. B.] 



j HYMENOCALLIS. A genus of beautiful 

 pancratiform Amaryllidacece, consisting oE 

 bulbous plants, with usually persistent 

 lorate leaves and flattened two-angled 

 solid scapes, bearing an umbel of from one 

 to a score of flowers, which are white 

 and very fragrant. The perianth has a 

 straight elongated tube scarcely widened at 

 the throat, a six-parted limb of subequal 

 linear segments, a funnel-shaped or rotate 

 spreading coronet on the edge of which the 

 six stamens are developed, and a long 

 flaccid declinate style with a roundish mi- 

 nutely fimbriated stigma. There are some 

 score or more of species inhabiting the 

 West Indies and South America. [T. M.] 



HYMEXOCARDIA. A genus of the An- 

 tidesmia family, differing from the others 

 in having samaroid (somewhat maple-like) 

 fruits. Of four known species three belong 

 to "West Africa, and one to the Malay penin- 

 sula. They are deciduous shrubs or small 

 trees, with ovate oblong or elliptical leaves 

 covered with glandular dots underneath, 

 and minute reddish flowers, the sterile and 

 fertile borne on different plants, the for- 

 mer in short axillary spikes, the latter so- 

 litary or in racemes. These are succeeded 

 by two-celled two-winged fruits. Sama- 

 ropyxis is the name applied to the Malayan 

 species by Miquel. [A. A. B.] 



HYMEXOCYSTIS. A name proposed by 

 ileyer for the Caucasian Woodsia fragilis. 



HYMEXODICTYOX. A erenus of Indian 

 trees closely related to Cinchona. The dis- 

 tinguishing features are the projecting 

 style, terminated by a lobed, somewhat 

 club-shaped stigma; and the fruit, which 

 is not surmounted by a limb of the calyx, 

 j forming a capsule, bursting by two valves. 

 The seeds are numerous, surrounded by a 

 membranous netted wing, whence the 

 name. H. excelsum a native of Ceylon and 

 the peninsula of India, and H. utile a native 

 of Malabar, have soft mahogany- coloured 



wood. The bark of the first-named is very 

 astringent, as much so as that of the true 

 cinchonas. This bark is used for tanning 

 purposes. [M. T. M.] 



HYMEXODIUM. The principal species 

 of this genus of acrostichoid ferns is a 

 coarse simple-fronded West Indian plant, 

 with large oblong-ovate fronds, sprinkled 

 over rather thickly with long black hairs. 

 The fertile fronds are of the same form, 

 but smaller, and entirely covered with 

 spore-cases on the under surface. The veins 

 are uniformly reticulated in coarse hexago- 

 nal or elongated meshes, without free vein- 

 lets. Also called Bictyoglossum. [T. M.J 



HYMENOGLOSSUM. A name proposed 

 by Presl for the Hymenophylhun crucnium 

 of Chili. 



HYMENOL^ENA. A genus of umbelli- 

 fers, having the fruit ovate or oblong, each 

 half with five nearly equal winged ribs, 

 and two oil-cells in the commissure. The 

 species are smooth perennial herbs, natives 

 of Nepal, having much-divided leaves, and 

 terminal many-rayed umbels, each sur- 

 rounded by a many-leaved involucre, the 

 pieces of which are membranous, often 

 toothed or cut. [G. D.] 



HYMENOLEPIS. A small and well- 

 marked genus of polypodiaceous ferns, 

 referable to the tribe Pleurogrammece. The 

 fronds are simple opaque and linear Ian- J 

 ceolate or lorate, with the apex very much 

 contracted, usually spike-like and fertile, 

 so much contracted, indeed, that the con- 

 tinuous line of spore-cases which lies on 

 each side the costa is in the early stages 

 cove? - ed by the revolute margin, as in the 

 fertile parts of Lomaria. The veins are 

 compoundly anastomosing, forming crowd- 

 ed irregular areoles, in which occur va- 

 riously directed free veinlets. The species 

 are found in India and the islands of the 

 Pacific and Indian Oceans. [T. M.] 



HYMENOMYCETES. The highest of the 

 six great divisions of Fungi, containing 

 those naked-spored genera, in which the 

 fructifying surface or hymenium is at 

 length completely exposed. In a few of 

 the agarics and boleti, there is at first a 

 common wrapper (volva), or a partial 

 veil covering the hymenium, but in far 

 the greater part it is exposed even in in- 

 fancy. The hymenium literally applies to 

 the fruit-bearing stratum only, the organs 

 on which it is spread being called the 

 hymenophorum, but in general it is ap- 

 plied to the whole apparatus, whether con- 

 sisting of gills, wrinkles, tubes or pores, 

 spines or tubercles, or if all inequalities 

 in the surface cease and it becomes per- 

 fectly even. In the higher species, the 

 hymenium is horizontal and turned away 

 from the light, but in those of an inferior 

 dignity it is often resupinate, though in 

 such cases there is frequently a tendency 

 to attain the usual position by theturning 

 over of the border. Iu a few rare cases, 

 on the contrary', amongst agarics, where a ' ! 

 species was in the first instance stipitue, 



