176 Mr. J. Miers on some genera of the Icacinaceae. or papillary tubes, here sloping outwards on each side the cord ; c, truncated vessels of the marginal plexus ; d, d, small channels of intercameral communication ; e, grand semilunar or crescentic channel of ditto ; /, septum. Fig. /• Diagram of vertical section to show the situation of the interseptal vessels : a, a, interseptal vessels ; h, septum ; c, grand channel of intercameral communication ; c?, part of spicular cord. Fig. 8. Enlarged view of first-formed chambers of Operculina Arabica : a, central cell or chamber ; b, b, b, probable forms of last cham- bers in process of development. Fig. 9. Diagram of vertical section of Nummulites acuta, Sow. : a, spicular cord ? ; b, truncated vessels of marginal plexus ; c, c, chambers of central plane; d, d, vertical interseptal vessels (the "perforations," &c. of Dr. Carpenter) ; e, e, horizontal interseptal vessels ; /, /, /, chambers on each side the central plane ; g, g, g, vertical tubes. XVI. — On some genera of the Icacinacese. By John Miers_, Esq., F.R.S., F.L.S. [Continued from p. 119.] Emmotum. This neglected genus was proposed by Desvaux in 1825 upon a plant from Guiana. By Endlicher it was referred to Leretia of the ' Flora Fluminensis/ with which it neither accords in the appearance of the leaf nor the mode of its inflorescence : Hamil- ton's character as given in his ' Prodromus/ notwithstanding its brevity, is sufficiently well marked to show that it does not differ from Poffopetalum, founded by Mr. Bentham in 1840 ; indeed the Emmotum fagifolium J Desv., corresponds with Pogopetalum acu- tuMj Benth., both from Guiana, so as to leave no doubt of their identity : according therefore to the austere rule of science, the latter name must give way to the former. Mr. Bentham in establishing his genus recorded two species, and has since de- scribed two others, and I have now to add a fifth. All the spe- cies, which are from Guiana and intertropical Brazil, seem to form good-sized trees, with very thick coriaceous leaves of a peculiar appearance ; their inflorescence is in axillary crowded fascicles of rather small flowers, which are distinguished by having petals densely beset on their inner face with long red silky hairs arising from an elevated costal nervure. Their chief peculiarity, however, consists in the unusual structure and sin- gular mode of dehiscence of their anthers, which are formed of two opposite, unilocular, valveless, and separate cells, the pollen being discharged extrorsely through a fissure arising from the secession of the dorsal margin of each boat-shaped cell from the very fleshy connective, features that have hitherto escaped obser- Mr. J. Miers on some genera of the Icacinaceae. 177 "vation. Emmotum offers also another peculiarity in its ovarium with three radiate cells, placed excentrieally on the somewhat gibbous and anterior side of the ovarium. These points of struc- ture are so different from the development met with in other genera of the Icacinacece, as naturally to lead to the suspicion that Emmotum may not belong to this family; but we must remember that in other respects it accords, viz. in its exstipulate alternate leaves, small flowers with a persistent unchanged calyx, petals with valvate aestivation, alternate stamens, simple style, and suspended collateral ovules. I have therefore retained the genus doubtfully, as a separate tribe of the Icacinacea {ante, S. 3. vol. ix. p. 223), until its true place in the system can be ascertained, which will be determined by a knowledge of the structure of the fruit and seed and the form and position of its embryo. The name, I presume, has been derived from £v and jjbOTo^j linteum, on account of the densely intertwined hairs that line the petals, a character that also suggested the name of Pogopetalum. These hairs, when examined under the microscope, appear flattened and covered with numerous promi- nent transparent glandular dots as in Lereiia, The following is sxi outline of its generic features : — Emmotum, Desv. Pogopetalum, 5ew#A. — F/ores perfecti. Calyx brevissimus, 5- rarius 4-dentatus, liber, fructifer immutatus. Petala 5, rarius 4, lineari-oblonga, carnosula, intus ad cari- nam longitudinalem pilis rufis ssepius longis et crispatis den- sissime barbata, sestivatione valvata, mucrone apicali introflexo. Stamina 5 vel 4, petalis alterna, iis vix breviora, omnino libera ; filamenta carnosula dilatata, incurva, apice repente acuta ; an- ther ce 2-loculares, connectivo crasso, interdum loculis utrinque sejunctis breviores, vel ssepe in mucronem subulatum incur- vulum ultra loculos subantrorsim positos producto, imo cor- dato affixee, loculis membranaceis, cymbseformibus, evalvibus, margine posteriori a conjiectivo omnino soluto hinc extrorsim dehiscentibus. Pollen ovale, longitudinaliter sulcatum. Ova- rium liberum, oblongum, subgibbum, pilosum, disco hypogyno parvo sistens, 3-loculare, loculis excentrice radiantibus ; ovula in quoque loculo 2, juxta apicem appensa et subcoUateraliter superposita. Stylus excentricus, erectus, teres. Stigma e den- tibus 3 brevissimis erectis minutum. Drwpa globosa, abortu 1-locularis; csstera ignota. — Frutices Guianenses et Brasi- lienses sempervirentes ; folia alterna, exstipulata, coriacea, In- tegra, nitida, subtus tomentosa ; cymse fasciculatce, axillares, multiflorce ; flores parvi, aggragati, cum pedicellis brevissimis articulati, bructeati. Ann. ^ Majg, N. Hist, Sen 2, Vol x. 12 178 Mr. J. Miers on some genera of the Icacinacese. 1. Emmotvm orhiculatum. Pogopetalum orbiculatum, Benth. Linn. Trans, xviii. 685. tab. 43 ; — arbor 2-orgyalisj ramulis cinereo- vel fulvo-tomentosis_, foliis ovato-orbiculatis^ apice bre- vissime ac obtusissime acuminatis, coriaceis, nitidis, supra lucidisj rachi tomentoso, nervis parallele incurvo-divaricatis, venis creberrime transversis immersis, subtus cum petiolo crasso profunde canaliculate incano- vel fulvo-tomentosis ; ovario hispido, fructu globoso, calyce immutato suffulto. — In Guiana Brasilia3 ad fluv. Padauri, confl. fiuv. Nigri. — Schom- burgk. — [v. s. in herb. Mus. Brit, et Hook, fructu immaturo^ Rio Preto, Prov. Pernambuco. — Gardner, n. 2941.) This species is remarkable for the shape of its leaves, which are almost orbicular at the base and summit, are 2f to 3J inches long, 2~ inches broad, on a deeply grooved petiole 6 or 7 lines in length ; they are thick and coriaceous, very polished above, with a finely shagreened surface, and densely covered beneath with short yellowish tomentum : the simple racemes with a few immature drupes are about f inch long. 2. Emmotum acuminatum. Pogopetalum acuminatum, Benth. he. supr. cit. 685 ; — arbor 5-orgyalis, foliis ovatis oblongisve, apice longissime et anguste attenuatis, mucronulatis, coriaceis, fusco -rufulis, supra lucidis et glaberrimis, in costam sulcatis, nervis paucioribus vix prominulis, venis transversis immersis, subtus pallide ferrugineis, glandulis minutis creberrime punc- tatis, pube rara instructis, petioloque sulcato leviter pubescen- tibus, demum glabris; racemis geminis, fioribus aggregatis griseo-pilosis, petalis ovali-oblongis, intus in carinam pilis longis rufis lanatis, marginibus utrinque glabris ; ovario pilis destitutis et e glandulis minutissimis asperis glauco-pruinoso, disco glabro insito ; stylo excentrico elongato, stigmate obso- lete 3-dentato. — Rio Negro, Brasilise (Schomb. 970). The branchlets are somewhat compressed and angularly striated : it is however distinguished from the other species by the long attenuated summit of the leaves, which are also of a remarkably dark copper or reddish colour when dried ; they are about 4 or 4| inches long, including the suddenly narrow apex of half an inch in length ; they are If to 2|^ inches broad, on a petiole 5 lines long ; the nervures, about seven pairs, are parallel, very divergent, curving, with finely reticulated transverse veins ; the upper surface is polished and finely shagreened ; beneath they are of a ferruginous hue, dead, almost glabrous, and when viewed under the lens seem covered with minute raised glandular dots : generally two racemes spring out of each axil, from g^ to f Mr. J. Miers on some genera of the Icacinacese. 179 inch long, which, when younger, appear Uke a crowded globular axillary fascicle. The anthers in structure resemble those of the following species. The long red hairs that densely spring from the inner keel of the petals under the lens appear marked by large prominent glands in two uneven series, so that they seem almost torulose. 3. Emmotum fagifoliumy Desv. in Ham. Prodr. Fl. Ind. Occid. p. 29. Pogopetalum acutum, Bcnth., Hook. Lond. Journ. Bot. ii. 377; — ramis angulatis, rufo-tomcntosis ; foliis oblongis, ovatisve, apice repente lineari-attenuatis, basi rotundatis vel truncatis, valde coriaceis, supra sublucidis, glaberrimis, nervis divaricatis, pubentibus, approximatis, incurvo-parallelis, sul- catis, venis transversis immersis, subtus prsesertim in nervis sparse sericeo-pubescentibus, nervis tenuibus subprominulis, petiolo canaliculato tomentoso; racemis geminis, axillaribus, petiolo vix longioribus, floribus aggregatis, aurantiaco- vel cano-tomentosis, petalis lineari-oblongis, intus pilis longis rufis in carinam lanatis, lateribus glabris, tilamentis tenui- oribus, dilatatis, antheris ovatis, vix mucronulatis, loculis op- positis, complanatis, ovario pilis longis hispido (nee glabro), stylo elongato, gracili. — Guiana Gallica, Desvaux. — v. s. in herb. Hook. (Leprieur et Martin). There can be little doubt that this is the plant described by Desvaux as the " Bois d'Agoitti," and which is identical with the Pogopetalum acutum of Mr. Bentham : the leaves in form much resemble those of the preceding species ; they are from 3| to 6| •inches long, and 2^ to 3| inches broad, on a slender petiole half an inch in length ; the apex is very suddenly acuminated by a linear point, half an inch in length, and often little more than a line in breadth. The flowers are closely aggregated, each being articulated on its short pedicel ; the calyx is cupuliform, pubes- cent, and cleft into five ovate, fleshy and somewhat acute lobes, which are slightly imbricated in aestivation, as in Flatea; the petals are clothed outside with short gray adpressed hairs, and the prominent internal keel is furnished with a line of very densely-set long red spreading woolly hairs, which are flattened and marked with glandular dots ; the stamens are nearly as long as the petals ; the filaments are fleshy, compressed and broader at the base, somewhat terete and subulate above, and suddenly bent back at the apex, where the point is afiixed to the front of the red fleshy connective, just above its short basal sinus ; the anthers are therefore strictly extrorse ; the connective is almost terete, somewhat compressed, erect in position, and about one- sixth of the length of the filament; the two anther-cells are di- 12* 180 Mr. J. Miers on some genera of the Icacinacese. stinctly separate, thin, membranaceous, white, flattened, boat- shaped and vnlveless, fixed one on each side of the connective; they are longer both above and below, so that the anthers are emarginated at the apex and base ; they generally open extrorsely by the separation of the posterior margin of the cells from the connective, or they sometimes, though rarely, separate by both margins. The ovarium has been described as being glabrous, but I have constantly found it clothed with long, erect, setaceous, shining, white hairs ; the lower part is invested by a glabrous, adnate, cupshaped disk : the style is erect and somewhat bent, glabrous, rather subulate, slender, and of the length of the sta- mens : there is no apparent stigma, but the apex of the style is hollow and crowned with three very minute teeth : the ovarium contains three radiate, excentric cells, each showing two ovules suspended from near the apex. 4. Emmotum affine, n. sp. Pogopetalum affine. Planch. MSS. ; — foliis ovalibus e basi rotundato gradatim angustioribus apice fossulato et deflexo longe attenuatis, subconvexis, supra niten- tibus, costa sulcatis, nervis subprominulis, venis creberrime transversis immersis, subtus ferrugineis, et glauco-pruinosis e pilis brevissimis adpressis sub lente visuris, margine valde re- flexo, petiolo subtenui sulcato rufo-glaucescente ; racemis axil- laribus, floribus aggregatis cano-pilosis, petalis intus in cari- nam pilis longissimis rufis dense lanatis lateribus glabris : sta- minibus spec, prseced. : ovario piloso, disco glabro insito. — Brasilia. — v. s. in herb. Hook. (Sellow.) This species comes very near E. acuminatum ; the leaves are very shining above as in that species, and ferruginous beneath, but the hairs that clothe its under surface are so minute as to be seen only under a strong lens ; they are somewhat convex above and the margins are very revolute, the attenuated apex being deeply channelled and curved downwards ; they are about 4J inches long and 2 inches wide, with a somewhat slender and almost terete petiole, which is often suddenly deflexed. The in- florescence is axillary in a few of the upper leaves, but is mostly terminal in branching alternate racemes, each about three- quarters of an inch long. 5. Emmotum nitens. Pogopetalum nitens, Benth. loc. citat. ; — ramis striatis ; foliis oblongis, acuminatis, coriaceis, supra gla- berrimis, pallide glaucis, sub-nitentibus, subconvexis, nervis subprominulis, venis transversis immersis, subtus pube sericea adpressa densa incana aut fulva vestitis, nervis valde promi- nentibus, margine reflexo, petiolo elongato cano-tomentoso Mr. J. Miers on some genera of the Icacinacese. 181 canaliculate saspe deflexo ; paniculis racemosis, temis, axilla- ribus, petiolo sublongioribus, floribus dense aggregatis, grisco- pilosulis^ pctalis lineari-lanceolatis, acutis, sum mo patcntim reflexis, intus ad carinse basin apicemque fascicule pilorum donatis, pilis brevibus albidis ; staminibus incurvis crassius- culis, connective tereti, imo cordato, in mucronem obtusura incurvum longe protenso, antherarum loculis sejunctis, antice contiguis, subparallelis, margine dorsali dehiscentibus ; ovario pilis brevibus micantibus adpressis vestito, disco glabro insito ; stylo brevissimo valde excentrico. — Brasilia intertropica; — v. s. in herb. Hook. — Pj^ov. Goyaz, Minas Geracs et Pemambuco (Gardn. n. 294 J, 3309, 4451); Rio S. Francisco (Blanchet, 2889). In this species the leaves, in the dried state, present a re- markably pallido-glaueous and lurid aspect above, and are co- vered below with yellow, very short, adpressed and bright tomen- tum ; the upper surface is shining, with prominent nervures, and under a lens appears marked with numerous minute impressed dots, between which are seen still more numerous raised resinous spots ; they are generally about 4 inches long and 2 inches broad, on a longer and more slender petiole, about 9 lines in length. One, two or three short branching racemes, about the length of the petioles, crowded with numerous flowers, spring from each axil ; the stamens are incurved, about the length of the petals, the anthers being nearly as long as the broad fleshy filaments ; the thick, fleshy, almost terete connective is slightly cordate at its base, is somewhat incurved and subulate, and ter- minates in an obtuse point that much exceeds the length of the anther-cells; this is affixed just in the angle of its sinus in front, to the obtuse apex of the filament, so that the anthers, though at first sight apparently basifixed, are in reality also extrorse in position : the anther-cells are white, of thin texture, linearly boatshaped, quite separate, nearly parallel, and fixed extrorsely upon the sinus of the inner face of the connective, and they dis- charge their pollen by the secession of the exterior margins from the body of the connective. The pollen is oval, marked by three longitudinal lines. The ovarium is shorter than the stamens, covered with short erect hairs, and seated on a small fleshy glabrous disk ; it is 3-celled as in the last- described species ; the style is very short, very excentric, hollow at its apex, and termi- nated by three very minute teeth.