shaped perianth contracted at the throat, 

 where it is provided with a plicated ring 

 or ' corona.' The anthers are twelve in 

 number, arranged in two rows : the outer, 

 on triangular filaments, open inwardly, 

 and are partially united together ; the inner 

 ones are sessile, open outwardly, and have 

 their connective prolonged into a lance- 

 shaped point. The plant has the appear- 

 ance of Asarum, from which genus the 

 above characters amply distinguish it. Its 

 leaves are heart-shaped, marked with white 

 spots. [M. T. MJ 



HETEROTROPAL. Lying parallel with 

 the hilum. A term applied only to the 

 embryo. 



HETRE. (Fr.) Fagus sylvatica. 



HEUCHERA. A genus of perennial 

 herbaceous plants of elegant appearance, 

 natives of North America and Siberia, and 

 included in the Saxifragacece. The petals 

 are five, inserted into the upper part of the 

 tube of the calyx, of a linear form and 

 slightly unequal ; stamens five, inserted 

 with the petals ; ovary one-celled, with two 

 parietal placenta? ; styles elongated, diver- 

 gent; fruit bursting between the styles. 

 The flowers are borne in clusters which 

 rise from a number of lobed toothed 

 leaves. Several of the species are grown 

 in English gardens. The root of H. ameri- 

 cana is so astringent that it is called Alum 

 root. [M. T. M.J 



HEWARDIA. A genus of polypodia- 

 ceous ferns, agreeing with Adiantum in all 

 the essential points of fructification, but 

 distinguished from it by having the veins 

 reticulated. They have linear continuous 

 sori, as in Adiantum Wilsoni and its allies, 

 and are pinnate, bipinnate, or pedately tri- 

 pinnate plants of South America. It is 

 named after Mr. R. Heward, anamateurpte- 

 ridologist, and one of the contributors to 

 this work. The name has also been given 

 to a melanthaceous stemless herb from 

 Tasmania, having ensiform distichous 

 leaves, and star-shaped purple flowers, 

 and the habit of an Iris or Sisyrinchium ; 

 but for this the name of Isophysis has been 

 suggested. [T. M.] 



HEXA. In Greek compounds = six. 

 Tims: Eexalepidous, consisting of six 

 scales : Hexapterous, having six wines or 

 membranous expansions : Eexapyrenous, 

 having six stones ; E exapetaloid, consisting 

 of six coloured parts, like petals ; Eexa- 

 rinous, having six stamens. 



HEXACENTRIS. A small genus of Acan- 

 fftarap.containing three species from India. 

 They are climbing shrubs with dentate 

 leaves, and purple or yellow flowers in ax- 

 illary and terminal many-flowered racemes. 

 The small calyx is unequally toothed, and 

 is surrounded by two small bracts. The 

 corolla has a short tube and an oblique five- 

 cleft limb. The four didynamous stamens 

 have erect two-celled anthers, which, in the 

 shorter pair, have both cells spurred, aud 

 the longer pair have a spur on one only. 

 A short subulate sterile fifth stamen is 



present. The stigma is bifurcate. E. my- 

 sorensis is very ornamental. [W. C.j 



HEXADESMIA. A few epiphytal or- 

 chids of Central America, differing from 

 Epidendrum in having six instead of four 

 pollen-masses; whence the generic name. 

 They are tufted plants a few inches high, 

 with narrow oblong pseudobulbs, a few 

 short grassy leaves, and a number of in- 

 conspicuous green or white flowers in a 

 terminal raceme. [A. A. B.] 



HEXAGONIA. A fine genus of pore- 

 bearing Fungi, distinguished by its large 

 angular pores, which resemble the ceils 

 of a honeycomb. Most of the species are 

 hard and woody, hut one or two are thin 

 and flexible as paper. They are, with but 

 one or two exceptions, inhabitants of tro- 

 pical countries. We have no species in 

 Great Britain, but E. sericea is found in 

 the forests above Canada. One or two 

 species are found on gum trees in Aus- 

 tralia. In some Indian species the pores 

 are one-sixth of an inch across. [M. J. B.] 



HEXALOBUS. A genus of anonaceous 

 shrubs, inhabiting Senegal and Madagas- 

 car. They have a six-cleft corolla, with 

 the spreading segments- in two rows ; nu- 

 merous club-shaped stamens, attached to 

 the sides of a convex receptacle ; and nume- 

 rous ovaries with sessile stigmas; fruit 

 of several few-seeded berries. [M. T. M.] 



HEYNEA. A genus of Indian trees be- 

 longing to the Mcliacece, among which 

 they are distinguished by the tube formed 

 by the union of the stamens, which is 

 deeply five-cleft, the segments being also 

 cleft ; the anthers are ten, sharply pointed ; 

 ovary two-celled, imbedded in a fleshy 

 disk, and ripening into a somewhat fleshy 

 capsular fruit, which is one-celled by abor- 

 tion and single-seeded. [M. T. M.] 



HIANS. Gaping ; opening by a long nar- 

 row fissure cut across the shorter axis. 



HIBBERTIA. A genus of Dilleniacece 

 confined to Australia and Tasmania, com- 

 prising about fifty species. They usually 

 form little heath-like tufted shrubs, or their 

 slender stems trail along the ground, but 

 occasionally they grow several feet in 

 length and climb upon other shrubs. Their 

 flowers are yellow, borne at the ends of the 

 branches, and generally give out a very un- 

 pleasant odour ; they have five thick lea- 

 thery permanent sepals, and five thin fuga- 

 ceous petals; the stamens are very nume- 

 rous, entirely free or united at their bases 

 into several bundles; and the one-celled 

 ovaries, two to five in number, are termi- 

 nated by a diverging style. The fruit con- 

 sists of two or more carpels splitting open 

 down the inner edge, and containing one 

 or several roundish shining seeds, each 

 partly surrounded by an aril. 



E. dentata, a climbing species, is one of 

 the most showy, and grows six or eight feet 

 high. E. grossulariwfolia is another of the 

 climbing kinds, having leaves somewhat re- 

 sembling those of the common gooseberry 

 bush, its trailing stems tinged with red, and 



