XXII. 0% Acradenia, a new Genus of Diosmeae. By RICHARDKIPPIST, Esq., fibr. L.S.

Read June 1, 1852.

THE plant to which I propose to call the attention of the Society this evening, is one of a highly interesting collection, formed in the neighbourhood of Macquarie Harbour, by the indefatigable Secretary of the Royal Society of Van Diemen’s Land, Mr. Joseph Mil- ligan, by whom, through the instrumentality of our lamented member, Mr. Bicheno, they were kindly presented to the Society. It belongs to the Diosmeous section of Rutacece (Tribe Boronieg), and in habit most nearly approaches Zieria, to the larger-leaved species of which it bears, at first sight, con- siderable resemblance. From this genus, however, as well as from Melieope, Boroniu, and Cya?zothamizzcs,it is readily distinguished by the quinary division of the parts of the flower, and by its more numerous stamens. From Eriostemoiz, Crowen, and Philothem, with which it agrees in the number of its floral organs, it differs in having perfectly glabrous filaments, and smooth inappendiculate anthers ; and from the latter genus, in addition, by the filaments being distinct, not, as in Philotheca, united below into a tube. Another genus of Australian Diosme~cwith which it accords very nearly in many of its artificial characters, is Gelexnovia, a remarkable plant with the general aspect of Erio- stemon, recently described by Turczaninow, from Drummond’s Swan River Collections, in the Bulletin of the Imperial Society of Naturalists at Moscow. The points of agreement are, the quinary division of the calyx and corolla, the smooth subulate stamens (ten in number), and glabrous inappendiculate anthers ; but the calyx in Gelenzovia is coloured, and as long, or rather longer, than the corolla, the anthers are strictly terminal, and the entire surface of the carpels is covered with elevated tubercles, each surmounted by a tuft of radiating hairs. From all the above-mentioned genera the Tasmanian plant is distinguished by the structure of its ovaries, which adhere closely together, and are everywhere clothed with a dense tomentose covering; except that each bears, at its upper external angle, a naked sessile tubercle or gland, large enough to be readily observed with the naked eye ; a cha- racter which I have been unable to discover in any closely allied genus, and it has con- sequently suggested the name Acradenia, by which I would propose to designate my plant. I am unable to speak positively as to the precise nature of these glandular bodies, or to say whether any exudation proceeds from them: when examined under the micro- scope, they appear to be perforated by a tube, widening below, and communicating with the internal cavity of the carpel. From the exact correspondence in their position, how- ever, they are probably analogous to the cornute appendages which crown the ovaries of 20s MR. KIPPIST ON ACRADENIA, some species of PAebaZizcm, but in that genus they are occasionally developed into subu- late or nearly cylindrical horns, almost as long as the carpels themselves. In the structure of its mature capsule, Acraclelzia appears to differ from most, if not the whole, of its more immediate allies, the endocarp remaining, when ripe, hnly united to the epicarp, instead of separating from it in two elastic valves, as is usually the case in other Diosmecc. We have, unfortunately, no information from its discoverer with respect to the dimen- sions which the plant attains, but the dried specimens have all the appearance of having been broken off from a .shrub of considerable size. They are much branched, and copiously furnished with opposite ternate leaves ; these are remarkable for their coriaceous texture, and the extreme roughness and harshness of their upper surface, which is dark green, and covered with prominent glandular tubercles, while the under side is perfectly even, and (in the dried specimens) of a ferruginous brown. From its close resemblance in habit to Zieria, I had originally intended to employ the specific name “ zierioides ”; but Mr. Brown having kindly communicated to me a speci- inen, gathered by Mr. Milligan on the banks of the Franklin River in April 1842, on n ticket attached to which Mr. Milligan proposes to name the plant “ Zieria FrunkZii&,” aRer Lady Franklin (who, with her husband, Sir John, were, I believe, his companions on that journey), I have much pleasure in altering the specific name to FmnkZini&, in accord- ame with the wishes of its discoverer. On the same ticket Mr. Milligan speaks of the plant as handsome and fragrant ; but as he at that time saw no flowers, the latter term can only be intended to apply to the leaves, which, as in the majority of the DiosrneE, are copiously furnished with pellucid dots, reservoirs of essential oil, and exhaling probably the peculiar odour which characterizes that family.

ACRADENIA.

CHAR.ESSENT. Calyz 5-partitus. Petala 5, hypogyna, calyce multo longiora, restivatione imbricata, ovato-elliptica, undique velutina. Etaminu 10, hypogyna, petalis sublongiora, alteriia Paul6 bre- viora ; planrenta libera, subulata, glabra ; anthers introrsae glabrc, biloculares, rim& longitudinali dehiscentes, apice inappendiculatae. Ovaria 5, gynophoro disciformi margine sinuato insidentia, 1 -locularia, villosissima ; singulo apice glandulh majusculg sessili instructo. Ovula in loculis gemina, suturae ventrali collateraliter inserta, pendula. Styli in unicum glabrum coaliti. Stigma subcapitel- latum. Capsula 5 - (vel abortu I-%) rocca ;cocci subquadrati, compressiusculi, glabrati, npice trun- cati et extiis breve cornuti, coriacei, transversim rugosi ;endocarpio liaud secedente. Semina ...... 3. Frutex tasmanicus, ramosissimus ; foliis oppositis exstipulatis, petiolatis, 3-foIiatis ; foliolis coriaceis, Ian- ceolatis, serratis, suprh tuberculatis ; pedunculis terminalibus, trichotomt? CY~OE~S,multa$oris ; floribus albis. ACRADENIAFRANKLIXIB. Ziericc FpankZinie, Nilligan, MSS. Frutez ramosissimus, floribus ramulisque junioribus exceptis, glaberrimus. Rami teretes, oppositi vel subverticillati, cortice laevi vel subrugoso tecti. Folia opposita, exstipulata, breve petiolata, trifoliata. Petioli vix semipollicares, sup& canaliculati, subter convexi. Foliola 2-uncialia, coriacea, discolora, lanceolata vel obovato-lanceolata, margine revoluta, versus apicem obtusum serrulata, basi attenuata integerrima ; sup& glanduloso-tuberculata atro-viridia, subt2r yallidiora lzvissima vel glandulis miniis prominentibus par& conspersa, undique nitida ; nervo niedio vaiido utrinque prominente, venulis

A NEW GENUS OF DIOSMEZ. 209

immersis inconspicuis- Cymte terminales, trichotomae, multiflorae, pedunculo communi teretiusculo vel compress0 subpollicari, ramisque oppositis teretiusculis, pilis brevibus patulis velutinis nigres- centes. Bractes subulatae, pilis longioribus lutescentibus appressis dens2 tectie. Pedicelli divaricati ebracteolati (5-6 lin. longi). Calyx profundi: 5-partitus, sepalis ovatis, carnosulis, extiis margineque hirsutis, intiis glabris. Petala 5 (vel quandoque 4), calyce 5-pk longiora, aestivatione imbricata, sub anthesi patentia, ovato-elliptica, brevissimE unguiculata, basi sub 5-nervia, alba, undique pilis simpli- cibus crispatis velutina. Stamina 8-1 a, hypogyna (persistentia?), petala subsuperantia, alterna iisdem opposita pauli, breviora ;jilamenta omninb libera, lineari-subulata, laevia (sub anther&haud dilatata), glaberrima : anthwle introrsae, ovato-cordatae, glabrze, biloculares, rim& longitudinali dehiscentes, apice inappendiculatae. Ovaria 5, in germen pentagonum cohaerentia, gynophoro disciformi glabro margine sinuato insidentia, unilocularia, villosissima, singula apice ad angulum externum glanduli tuberculove majusculo sessili instructa. Ovula in quoque loculo gemina, suturae ventrali collateraliter inserta, pendula. Styli ex ovariorum apice in unicum, glabrum, angulatum, subulato-linearem, sta- mina subaequantem, germine subduplb longiorem, coaliti. Stigma subcapitellatum, vix lobatum. Capsula sub-pentacocca ; cocci (quorum 1-3 saepi? abortivi) basi subcohaerentes, sepalis pervistentibus plurss longiores, subquadrati v. rhomboidei, paulb compressi, basi rotundati, apice abrupt2 truncati et angulo externo brev6 cornuti, coriacei vel sublignosi, dorso carinati, transversini rugosi, extiis glabriusculi, intiis sulcati glabri ; endocarpio haud secedente. Semina...... a. Hub. ad margines sylvae densae prope Portum Macquarie dictum, Insula: Van Diemen; ubi floribus expansis legit Dom. Jos. Milligan mense Decembris 1846, et iterum Martii 1847. I take this opportunity of expressing my obligations to Sir William Hooker for having kindly afforded me the opportunity of examining the flowers in a living state; thus enabling me to supply some particulars with regard to colour, &c., on which little or no satisfactory information could be obtained from the dried specimens. I regret to find, however, that the plant is not likely at present to ripen its fruit at Kew. Mr. Smith informs me it was first introduced to the Botanic Garden in 1845, in a case sent by Dr. M'William from Norfolk Island, where, however, it is scarcely possible that it should be indigenous.

EXPLANATION OF THE PUTE. TAB.XXII. Fig. 1. A branch of Acradenia Frankliniq of the natural size. Fig. 2. Flower, with four of the stamens removed :-natural size. Fig. 3. Sepal :-magnified. Fig. 4. Petal :-magnified. Fig. 5. Stamen :-magnified. Fig. 6. Ovarium, seated on its gynophore :-magnified. Fig. 7. Transverse section of ovarium :-magnified. Fig. 8. Longitudinal sectiom of one of the carpels :-magnified. Fig. 9. Ripe capsule :-natural size.

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