# Illustrations of Indian Botany, Vol. 1/Aurantiaceae

XXXI.—AURANTIACEÆ.
This very beautiful, and on account of its fragrant flowers and delicious fruit, much admired order, of which the orange with its numerous varieties of lemons, limes, citrons, pumplemoses &c form the type, is generally well known in India (to which country indeed it almost exclusively belongs) even to the most casual observers of plants. But though so generally known in its more perfect forms, it is not always easy to recognize those more remote from the type of the family.
The order generally is composed of handsome flowering ever-green trees and shrubs, occasionally armed with strong spines, abounding in glands filled with volatile oil, usually very conspicuous in the leaves when held between the eye and the light, and exhaling a fragrant odour. Their leaves are alternate, simple, or compound. In the former as in the latter instance the petiols are jointed, indicating a tendency to become compound. So constantly is this the case, that simple leaves with such petiols are sometimes described as "pinnate reduced to the terminal leaflet." The petiols are often dilated or winged. The flowers are bisexual, for the most part white variously arranged in solitary and axillary flowers, or in racemes, panicles, corymbs, &c.
The calyx is short, more or less urceolate, or campanulate at the base, 3-5 lobed, withering. Petals equalling the number of the lobes of the calyx and alternate with them, inserted outside of the torus, broad at the base, distinct, or sometimes cohering, deciduous, imbricated in aestivation. Stamens equal or double the number of the petals, or more rarely, are very numerous and indefinite, inserted in a single series into the torus : filaments compressed, either altogether free or united into a tube, or variously polyadelphous, subulate, and free at the point. Anthers 2-celled, attached by the base, or the middle of the back, dehising longitudinally, introrse. Ovary free, 2-3-5 or many celled, with one or several ovules in each. Style cylindrical, or rarely wanting. Stigma large, somewhat lobed, or flat and spread over the apex of the ovary. "Fruit (an orange) consisting of several (or 1 by abortion) membranacious carpels, with or without an internal pulp, and surrounded by a thickish indehiscent rind, abounding in vesicles full of volatile oil. Seeds attached to the inner angle of the carpels, solitary, or numerous, usually pendulous : raphe and chalaza usually very conspicuous : Albumen none. Embryo straight, radicle next the hilum, partly concealed within the cotyledons. Cotyledons large, thick and amygdaline."
Affinities. The plants of this order are most readily known by the number of oily receptacles, which are dispersed all over them; the leaves, sepals, petals, and fruit equally partaking of them; by their deciduous petals, and compound leaves, and frequently winged petiols. By these peculiarities they are nearly related to Amyrideœ and Zanthoxylaceœ, from neither of which is it always easy to distinguish them, except by the fruit. Several species referred by Roxburgh to his genus Amyris, actually belong to this order. From the former they are distinguished by the numerous, not solitary, cells of the ovary, and by their baccate, not drupacious, or saniaroid, or legume-like fruit : from the latter their bi, not usually unisexual flowers, and their indehiscent pulpy fruit, not 2-valved dehiscent capsules seated on a gynophore, with a solitary shining black seed.
Geographical Distribution. Tropical Asia and her islands seem to be the native country of the order, a few only having been found indigenous elsewhere, of these two or three are from Madagascar, an island in which many other associates of the Indian Flora are found. DeCandolle in his Prodromus, excluding Aglaea, enumerates 43 species for the whole order : G. Don, who published some years later, raises the number to 60, but many of these doubtful : Blume found 21 in Java: Wallich's list has 37 : and 24 are described in our Prodromus as natives of the Indian Peninsula : one or two have been since added to the Peninsular list and I have several species from Ceylon, and some from Mergui. One species only, is found to withstand exposure to frost and snow, the Limonia lauriola, Wallich (PI. As. rar,) which is found on the tops of cold and lofty mountains, where it is for some months of the year buried under the snow.
Properties and Uses. The properties of the orange in all its protean forms of lemon, ​ lime, citron, pumplemose, bergamot, &o. are too well known to require notice here, but it is not generally known, that the pulp of the wood-apple (Feronia elephantum) affords a very pleasant jelly, so closely resembling black currant jelly that it is only to be distinguished by a slight degree of astringency which it communicates to the taste. In common with that of most of the order, the wood of this tree is very hard and durable, and not the less valuable for being found in most parts of India. The tree itself, is tall and handsome, with a straight trunk and a fine head, but the branches do not spread much. Ægle Marmelos equally attains the size of a considerable tree. I have not heard of the wood of this plant being used as timber, probably owing to the respect in which the fruit is held by the Hindoos. It is most frequently met with in pagoda gardens, the following extract from Roxburgh's Flora Indica, vol. 2 page 580, will explain the reason of the preference given to this species.
"This is the Bilva or Matura of the Asiatic Researches, vol. 2 page 349, from whence the following is an extract. 4 Uses. The fruit is nutritious, warm, cathartic; in taste delicious, in fragrance exquisite ; its aperient, and detersive quality, and its efficacy in removing habitual costiveness, have been proved by constant experience. The mucus of the seed is for some purposes a very good cement.' Note — ' This fruit is called Shreephula because it sprang, say the Indian poets from the milk of Shree, the goddess of abundance, who bestowed it on mankind at the request of Jowarra, whence he alone wears a chaplet of Bilva flowers, to him only the Hindoos offer them ; and when they see any of them fallen on the ground, they take them up with reverence, and carry them to his temple.'
The root, bark, leaves, and flowers are reckoned refrigerants by the Malabar physicians. The ripe fruit they esteem most wholesome."
As an ornamental garden shrub the Murraya exotica is much cultivated in this country, and well merits the distinction both on account of the beauty of the shrub itself, and the profusion and fragrance of its flowers; as a cultivated plant it rarely produces seed. Murraya paniculata which seems scarcely distinct is frequent in our jungles. The oranges, limes, and pumplemoses, are frequently cultivated in this country on account of their fruit, but the former very rarely with success on the plains, in Coromandel. The cause of this want of success is not ascertained, but I am myself disposed to attribute it to the heat being too high during the period of their ripening their fruit, for it is well known, that in the valleys at the foot of the Ghauts where the cold is much greater during that season of the year, they arrive at great perfection.
The red, loose skinned orange, which arrives at so great perfection in the alpine tracts of the Circars, and which is equally found on the mountains of the south, (but very inferior) is so very tenacious of an alpine country, that it has in the Circars received the name of hill orange. This, to my taste, when in perfection, is by far the most delicious of the whole tribe, but judging from the nature of the climate in which it is said to arrive at its greatest perfection, (a cold very humid atmosphere) it seems next to impossible to rear it successfully on the plains. It must be recollected, that the orange for the most part ripens its fruit during the cold season, showing that to attain perfection it requires a considerable range of the thermometer, the heat in their favourite valleys being high during the day, but low during the night, supplies this desideratum. I may here mention on the authority of the late Dr. Turner that the juice of the lemon, lime and citron, contains a large quantity of citric, and that of the orange malic acid.
Respecting the other species of the order a few words will suffice. Dr. Ainslie Mat. Ind. vol. 2 page 86-87, speaks very favourably of the medicinal properties of Ægle marmelos under the name Cratœva, adding however, that he has never seen the species, which is rather remarkable as it is to be met with in almost every pagoda garden. He informs us that a decoction of the bark of the root is considered on the Malabar coast a sovereign remedy against various forms of disease originating in indigestion, and that the fruit, a little unripe, is given in diarrhæa and dysentery : and Roxburgh (cor. plants) states that the Dutch in Ceylon prepare a perfume from the rind.
The leaves of the Bergera Konigii which are very fragrant, are much used by the natives as a seasoning for their curries, and are supposed stomachic and tonic. An infusion of the dried leaves is said to stop vomiting.
The young leaves of Feronia elephantum have a delightful fragrance resembling anise, hence they are considered stomachic and carminatine. From wounds in the bark of this tree a very transparent gum exudes, having the properties of gum arable, and is said to be better suited than it, for mixing colours for the painter. ​ Remarks on Genera and Species. The genera of this order are few, but require much nicety, and attention to minute organs, for their accurate discrimination; the structure of the ovary, which in most is very small, and the number and position of the ovules in its cells, affording the marks on which the greatest dependence can be placed, accordingly form the basis of our characters. The following synoptical table which I extract from our Prodromus will place this in a clear point of view. It contains an analysis of all those having stamina twice as numerous as the petals and a definite number of ovules in each cell of the ovary.
Ovules solitary, or 2 collateral in each cell. LIMO-NEÆ. Ovary cells as many as the petals :
Filaments combined 1. Atalantia.
Filaments distinct.
Stamens 6; , 2. Triphasia.
Stamens 8-10.
Style elongated (ovules 1-2 in each cell) 3. Limonia.
Style short, scarcely distinguishable : (ovules solitary.) 4. Glycosmis. Ovary cells fewer than the petals :
Style short, scarcely distinguishable; ovules 1-2 pendulous from the apex of the cells 5. Sclerostylis.
Style elongated; ovules solitary, peritropal, attached to the middle of the axis......................... 6, Bergera.
Ovules in pairs, one above the other. CLAUSENEÆ
Filaments distinct : Ovary cells fewer than the petals 7. Murraya.
Ovary cells as many as the petals;
Ovary hirsute; berry full of liquid ; flower-buds angled 8. CooKia. Ovary glabrous ; berry dryish ; flower-buds not angled; Stamens 8, dilated part of filaments concave ; petals oval 9. Clausena.
Stamens 10, filaments flat ; petals linear-lanceolate... Micromelum. Filaments (8) combined to the middle: (anthers linear : ovarium 2-3-celIed : style long: berry 2-3-celled With a resinous pulp : calyx tubular: petals 4.) Luvunga.
Of each of these genera, except the two last, detailed characters are given in the work; of them no Peninsular species have, so far as I am aware, been yet found. The plant which I have here, I now find erroneously, referred to Micromelum, differs widely in habit, though in structure it associates in many points, as may be seen by comparing the figure, with, the character given in the table of the ovary and flowers of that genus, — but I shall add to this account of the order the detailed generic character of Micromelum as given by Blume. Though I have not yet found Luvunga I will also, to facilitate its recognition should it be met with, extract Roxburgh's description of the flowers of his Limonia scandens, which is referred to this genus. Of the genus Sclerostyles, of which it was remarked when we wrote that Dr. Berry was the only person who had found it in the Peninsula, I have now specimens received from Malabar, Courtallum, Ceylon, and the Circars. Whence it would appear that so far from being so rare a genus as we then supposed, it is on the contrary but little if at all less frequent than Atalantia ; to which it bears so close a resemblance, that it is quite impossible to distinguish them with certainty otherwise than by an examination of the ovary or fruit, the 2 or 4 cells of which immediately marks the difference. (See Icones No. 71,) Of the genus Glycosmis I now possess one or two species in addition to those described in our Prodromus, but for which I find it difficult to assign characters suited to distinguish them from the preceding ones. This, of all the genera of the order, next perhaps to Citrus, is the most difficult to distinguish by written characters. To the genus Atalantia I now add one species and take away another : our Atalantia racemosa being in truth a Sclerostylis. The new species is distinguished from the old, by wanting the style and having the broad stigma adherent to the apex of the ovary; in all other respects it resembles the other. In his " Pugillus Plantarum Indiæ Orientalis" Dr. Arnott has given the character of a new genus of Aurantiaceœ under the name of Rissoa. This genus, judging from the characters only, I fear I cannot adopt, as I see no sufficient mark by which to distinguish it from Sclerostylis. Luvunga differs from both in having superposed not collateral ovules, but in other respects the characters are very nearly alike. Respecting the genus Citrus I have nothing to add, to what we have already said in the Pro​dromus, I have I acknowledge, found both wild limes and oranges in the course of my botanizings, but unfortunately did not devote, at the time, that degree of attention to their examination, relative to the solution of the question of species and varieties of this complex genus, which I ought to have done, and my specimens do not now enable me to do so. Mr. Royle is of opinion that Dr. Buchannan Hamilton, whose views we adopted, is wrong in considering all the Indian forms varieties only, of one species. I extract his paragraph on the subject as being the most satisfactory method of stating his opinion. See his Illustrations page 129.
" So great a diversity of opinion being entertained respecting the different plants of the genus Citrus, whether they should constitute species or varieties, it becomes difficult to say what are such, if only seen in a state of cultivation ; but as some are still found wild, an opinion may be formed, at least respecting those, In the tract of forest so frequently alluded to, as well as in the valleys within the Himalaya, I have seen two plants growing apparently wild, one called bijouree, and the other biharee nimboo ; the first having the characteristics of the citron, and the other, called also puharee kaguzee, those of the lemon : both when transferred to gardens retain their peculiar characters. From the Rungpore forests a round kind of lime is obtained : in those of Silliet, and as it is stated also on the sides of the Neelgherries, the orange is found wild. Captain Turner describes the oranges as delicious, and Mr. Saunders, who accompanied him, mentions finding many orange and lime trees at the foot of the hills in approaching Buxedwar (v. Turner's Tioet ; p. 20 and p. 387). Citrus decumanus Shaddock or Pompelmoses, does not appear indigenous to India, as its name, batavi nimboo or Batavia lime, denotes, as remarked by Dr. Roxburgh, its being an exotic ; and as it retains its characteristics even where it does not succeed as a fruit, it may also be reckoned a distinct species. I therefore feel inclined to consider as distinct species, the orange, lemon, lime, citron, and shaddock, without being able to say whether the sweet kinds should be considered varieties of the acid, or ranked as distinct species."
That both oranges and limes are found in an apparently wild state in our alpine jungles, is most certain, and it is equally certain that in other, not cultivated, genera, less obvious differences than the fruit, of these plants presents would be esteemed conclusive evidence of their being specifically distinct, whence, I have no intention of calling in question the opinion advanced in the above quotation, my only regret now being, that I did not give the subject more of my attion when 1 had better opportunities of determining the point.
The following detailed generic character of Micromelum is taken from Blume's Bijdragen, vol. 1st. page 137.
Micromelum Blume. — Calyx urceolate, entire, persistent, petals 5, linear spreading. Stamens 10, free: filaments subulate, alternately shorter: anthers roundish, didymous. Ovary 5-celled, cells 2 seeded, (superposed) style thick, stigma obtuse, berry dry, lamellated within, with 5 intorted (spirally twisted) papery dissepiments. Testa of the seed, (spermoderniis) membranaceous. Cotyledons, foliaceous, twisted.
A tree with unequally pinnated leaves, alternate, oblique, leaflets, and terminal corymbs.
One species only was known to Blume, namely, M. pubescens having from 7 to 9 ovate, obtuse, acuminate, leaflets, the under side of which with the young shoots and corymbs are clothed with pubescence.
It will appear from this character that the habit of the plant which I have figured, as a doubtful Micromelum, which is a scandent armed shrub with simple leaves and axillary flowers, differs widely from the true one, so much so indeed, that had I then been acquainted with the true Micromelum I should never have thought of referring it to that genus, even under the protection of a doubt. Since the figure was printed, I have had an opportunity of examining a true Micromelum and find it differs from my plant in another and much more important point, to which, when naming it, I did not sufficiently advert in the written character, namely, the intorted or twisted partitions of the fruit, and even of the ovary when but little advanced. Thus differing in structure, and so widely in habit I can no longer hesitate in considering this plant as forming the type of anew genus intermediate between Micromelum and Luvunga: having the quinary flowers and 5-celled ovary of the former, (but wanting its erect arborious habit, and the spiral partitions of its impregnated ovarium and fruit,) and the scandent habit of the latter ; (but wanting its 3-celled ovary and quaternary inflorescence.) My first thought, on discovering that it could not possibly be received as a Micromelum, was to refer it to Luvunga with a modified generic character, The character of Luvunga ​is to have quaternary sepals and petals, 8 stamens, and a 3- celled ovary, with 2 superposed ovules in each. To admit my plant it would require to stand thus— Calyx 4-5 lobed, petals 4-5. Stamens 8-10, free or united at the base Ovary 3 or 5-celled, with 2 superposed ovules in each. Scandent armed shrubs, with ternate, or simple leaves, and axillary solitary, or racemose, " pretty large, white, fragrant flowers" (Roxb.) Such a union is however very objectionable as combining two plants, one with the number of petals and cells of the ovary equal, and the other with them unequal. I therefore pursue what I consider the more judicious course, that of forming a genus for the reception of this plant.
Luvunga. — Hamilton. — The following is Roxburgh's description of the fructification of his Limonia scandens, now Luvunga, Flora Indica. 2 page 380. " Calyx 1-leaved, cylindric with the mouth cut into four short, truncate divisions. Petals 4, linear oblong, fleshy, recurved. Filaments 8 ; the lower half united into a firm, fleshy tube. Anthers linear, incumbent. Germ conical, elevated on a fleshy receptacle, 3-celled with 2 vertical ovula in each, attached to the axis. Style cylindric. Stigma entire, roundish. Berry oblong, somewhat 3-lobed, size of a pigeon's egg, pretty smooth, pulp of a resinous nature, and odoriferous, 3-celled. Seed solitary, oval, somewhat pointed at the apex, covered with a single greenish-veined integument. Perisperm none. Embryo conform to the seed, inverse. Cotyledons oblong, green, fleshy. Plumula 2-lobed. Radicle ovate, superior."
Two species of this genus are named in Wallich's list, namely, L. scandens and L. Tavoyana— Roxburgh thus characterizes the former, his Limonia scandens " Shrubby, scandent, armed, leaves ternate, leaflets lanceolar, entire : [flowers racemose,] : berries 3-seeded" Roxb.
The following character will I think distinguish my new genus from all the others of the order.
Paramignya R. W. —Calyx urceolate, obtusely 5-lobed at the apex. Petals 5, lanceolate. Stamens 10, free : filaments compressed, subulate at the point : anthers oblong, obtuse, attached by the back. Torus fleshy, cup-shaped, lobed at the apex ; embracing the base of the ovary. Ovary obtuse. 5 celled, partitions fleshy, not twisted. Ovules 2, superposed, in each cell, attached near the middle of the axis. Style thick, length of the stamens. Stigma capitate, obtuse, somewhat lobed at the apex. Fruit pomacious ! endorcarp 5-angled. between coriaceous and fleshy, surrounded by cellular pulp and rind, one (always ?) celled by the rupture and absorption of the partitions. Seed.— Scandent, armed shrubs ; spines axillary reflexed. Leaves simple, ovate, lanceolate, acuminated, glabrous. Flowers axillary, solitary, of rarely 3 or 4 together, rather large, white, very fragrant. The fruit ovate, obtusely 5-angled and furrowed between, clothed with short matted pubescence, the seed I have not seen.
The scandent habit, associates this genus with Luvunga, from which it is removed by the symmetrical petals and cells of the ovary, the predominance of the quinary not quaternary number of parts, and the free not united filaments, but above all, by the distinct endocarp of the fruit. I first found it in the jungles about Courtallum its long decumbent branches, spreading in all directions among the surrounding bushes, forming a nearly impenetrable brush-wood ; I afterwards received fine specimens through the kindness of Coionel Walker from Ceylon, and very recently one in fruit, but in a bad state for examination, from Mr. Nimmo, of Bombay. This last is the only fruit I have seen.
Only one species is yet known, the one here figured — It varies however in having larger, and more decidedly ovate leaves, and smaller thorns, differences depending I apprehend on luxuriance only.
The species of Micromelum the examination of which enabled me to determine, that the above was really a distinct genus, is a native of Ceylon, and does not seem to differ from Blume's M. pubescens.
ATALANTIA.
The following brief characters will sufficiently distinguish my two species of Atalantia.
A. monophylla DeC. Style as long as the stamens, stigma subcapitate, lobed.
A. platystigma. R. W. Style wanting, stigma large, flat, appressed to the apex of the ovary.
The habit and general appearance of both plants are the same.
GLYCOSMIS.
I mentioned above, that I had met with what I consider a new species of this genus. The following character may perhaps suffice to distinguish it from the preceding species.
​ S. macrocarpa. R. W. Shrubby, leaves pinnate, leaflets 3-5, oblong, lanceolate, attenuated at the base, acuminated above, quite entire : panicles terminal, corymbose small: fruit globose, about the size of a cherry, contracted at the base into a short podocarp.
Courtallum in dense jungles.
The large size of the fruit forms the best distinguishing mark : in all the other species it scarcely exceeds the size of a pea, in this it is as large as a moderate sized cherry.
SCLEROSTYLIS.
Of this genus there appears to be several species, all of which seem hitherto to have been confounded with Atalantia. Among my specimens I find the following series of forms each of which may perhaps be considered distinct species— and all distinct from Roxburgh's Limonia bilocularis our S. atalantioides. Taking that species as the original type of the Indian branch of the genus, it is distinguished from the following by having fascicled, subsessile, axillary and terminal, quinary, flowers: i.e. the calyx, 5-lobed: the corolla 5-petaled: and 10 stamens: filaments free, not united.
From this character all the other Indian and Ceylon ones with which I am acquainted depart in having quaternary flowers, some still further recede by having the filaments united into a tube as in Atalantia. Taking these marks as so many points of distinction the genus may be thus subdivided.
S. atalantioides W. and A.
† Filaments cohering into a tube.
S. racemosa (R. W.) Thorns large, leaves ovate, more or less emarginate, racemes axillary, simple or branched : flowers villous, subsessile, petals 4, stamens 8, filaments united to near the apex, into a tube, ovary 2 or 3-celied, fruit globose.
Atalantia racemosa (partly) W. and A. Prodromus, page 91.
S. parvifolia (R. W .) Sparingly armed, leaves narrow, elliptic, oblong, slightly acuminated and emarginate at the apex, racemes axillary, solitary, or paired, about as long as the leaves, flowers rather remote, longish pedicelled, segments of the calyx pointed, petals reflexed, filaments united into a tube, fruit globose, small.
Atalantia racemosa (W. and A.) partly.
This in the size and form of its leaves seems very nearly allied to Roxburgh's Limonia bilocularis, but differs in having racemose quaternary, not fascicled quinary flowers.
S. ovalifolia R. W. Leaves broadly oval, attenuated at the base, very slightly and obtusely acuminated at the apex, racemes axillary, short, few flowered. Flowers short, pedicelled, filaments united to the apex ; ovary 3 (always ?) celled, stigma clavate.
†† Filaments compressed free.
S. Arnottiana R. W. Armed, or occasionally without thorns, leaves ovate, very broad and rounded at the base, acute, or somewhat obtuse, and slightly emarginate at the apex, flowers axillary, fascicled, pedicels 1-fiowered, or rarely 2 or 3 flowered, filaments free to the base, compressed, suddenly attenuated at the point, anthers cordate at the base, stigma clavate.
Ceylon. — Colonel Walker.
The broadly ovate short petioled leaves and congested flowers, afford the best marks by which to distinguish this from the following.
S. Ceylanica. Leaves oval, attenuated at the base, very obtuse and entire, or slightly emarginate at the apex : racemes axillary, solitary, about half the length of the leaves, many flowered, (20 to 30) flowers longish, pedicelled, filaments free, much compressed, or somewhat winged, anthers cordate at the base, stigma clavate.
Ceylon.
One or other of these or perhaps both go to form, I think, Dr. Arnott's Rissoa ceylanica. So far as my specimens enable me to judge they ought to be kept separate.
In addition to these 5 species I have specimens of another from Malabar, but being in fruit only, I refrain from introducing it here. I may observe in conclusion that it appears to me the whole genus requires further revision.
MICROMELUM.
The only specimen I have seen of this plant closely resembles Bevgera Konigii in form. It is every where clothed with short while pubescence, the leaves are pinnate, leaflets 7-11, ovate, acuminate, blunt, emarginate, somewhat oblique at the base. Flowers small, numerous, forming large terminal corymbs, the ovary thickly covered, with longish while hairs. Should this on comparison with the Java plant be found to differ, I would recommend its being called M. Ceylanica,
PARAMIGNYA.
P. monophylla. Of this plant I have seen two varieties, but not sufficiently distinct to admit of their being considered species.
EXPLANATION OF PLATE 41.
1. Limonia alata— natural size. 2. A flower expanded. 3. Stamens. 4. Ovary, style and stigma, the calyx partly removed to bring them into view. 5. Ovary cut vertically, showing the pendulous collateral ovules. 6. The same cut transversely to show its 5 cells. 7. A full grown fruit. 8. A seed.--- 9. The same cut transversely.
EXPLANATION OF PLATE 42.
    1. Paramignya monophylla, R.W. (Micromelum? monophylum)—natural size.
    2. An expanded flower.
    3. The same, the calyx partially separated and the petals and stamens removed, to show the cup-shaped plaited torus, ovary, style, and stigma.
    4. Stamens and anthers, filament compressed, subulate at the apex.
    5. The 5-celled ovary eut transversely.
    6. The same cut vertically, showing the ovules superposed.
    7. A portion of a leaf magnified, to show the pellucid dots.
AURANTIACEÆ LIMONIA ALATA
AURANTIACEÆ MICROMELUM? MONOPHYLLUM (R.W.)