Illustrations of Indian Botany, Vol. 1/Malpighiaceae

by Robert Wight

XXXVI.—MALPIGHIACEAE.

A rather large order of tropical plants but principally confined to America, a very few being found in India, and these not of common occurrence. The greater number of Indian species are scandent shrubs, with jointed branches and opposite simple entire leaves, without dots, and minute stipules, some species of the order are clothed with appressed stinging bristles, others with silky pubescence. The flowers are for the most part bisexual, regular, racemose, or corymbose, rarely solitary, the pedicels often jointed in the middle and furnished with bractiols.

Calyx 5-sepaled, free or slightly united, persistent, imbricated in aestivation, and furnished with a definite number of conspicuous glands. Petals 5 unguiculate, inserted on a discoid torus, sometimes unequal, seldom wanting. Stamens 10, rarely fewer, filaments either distinct or partly united at the base, anthers roundish, 2-celled, opening by longitudinal lateral slits, introrse. Ovary usually 3-celled, occasionally more or less distinct, ovules solitary, pendulous, styles 3 distinct, or cohering into one. Fruit berried or dry, 3-celled, or by abortion, 2 or 1-celled and 1-seeded, often with the middle of the back expanded into a wing, seeds pendulous, attached to the central axis of the carpel, exarillate, albumen none. Embryo curved or straight : radicle superior, short. Cotyledons foliaceous, or fleshy.

Affinities. The affinities of this order do not seem to be very clearly defined, at least I do not find them so in any work I can refer to. They are distinguished from Acerineae by their unguiculate petals, glandular calyx, and symmetrical flowers : but in Erythroxyleae, which, as stated above, are considered a mere section of Malpighiaceae, the petals are sessile, and in Hiptage, the claw is so short as scarcely to deserve notice. Here however the position of the ovules assists to distinguish them, being pendulous in this, erect in Acerineae. It is said that those genera of Hippocrateaceae which have samaroid fruit have sessile petals, this is not a good distinction, since in H. Arnotliana, the claws of the petals are, in proportion to their size, fully as long as those of Hiptage, the direction of the radicle, however, is different, being in this superior, in that inferior ; from which it would appear, that Malpighiaceae are only distinguishable from Hippocrateaceae and other allied orders " by the radicle of the embryo being uniformly superior," while in them it is inferior, Meisner in his Plantarum Vascularium Gevera combines into his class Malpighinae the following orders, Hippocastaneae, Sapindaceae, Malpighiaceae, Acerineae, Erythroxyleae, Hippouratiaceae, and ? Corearieae, the characters of which

I give below in his own language, as presenting in few words perhaps the best and clearest view yet published of the distinctive marks of these very nearly allied orders.

MALPIGHINAE. (Classis).

Conspectus ordinum.

A. Germen conflatum ex ovariis 3 v. 2, plus minus inter se connatis.

I. Stamina calycis laciniis aequalia v. plura, plerumque dupla (rarissime in Malpighiaceis pauciora). Germinis loculi 1-2- (raro pluri-) ovulati.

† Semina exalbuminosa.

a. Semina hilo lato aut arillo praedita. Folia plerumque composita.

1. Folia opposita exstipulata palmatim 5-00-foliolata. Thyrsi terminales. Cirrhi 0. Flor. irregulares. Stam. 7, rarius 6 v. 8. Germ. 3-loc, loc. 2-ovulat., ovulo superiore pendulo inferiore adscendente. Caps, aptera, loculicide 3-2-valv., 3-1 -sp. Sem. exarill., hilo maximo.—Hippocastaneae.

2. alter na, pinnata aut pinnatisecta, rarius simplicia integra, rarissime stipulata. Pedunculi axillares, saepe cirrhigeri. Flores regular, v. irregul. Stam. petalor. numero dupla, duobus saepe deiicientib. Germ. 3-2-loc., local. 1-3-ovul., ov. adscendent. Drupa v. caps., carpellis saepe samaroideis.—Sapindaceae.

b. Semina nec ariilata nec hilo lato insignia, pendula aut adscendentia. Fol. plerumque simplicia.

1. Semina ope funiculi pendula, solitaria. Ovaria 3, interdum distincta. Carpella saepissime alata, rarius carnosa. Calyx persist., basi extus saepe glandulosus. Stam. 10, rarissime pauciora. (Fol. opposita, rarissime alterna, simplicia, interdum lobata, saepe stipulata.)—Malpighiaceae.

2. — adscendentia, sessilia. Ovaria 2, connata. Carpella extrorsum alata, saraaroidea. Calyx decid., eglandulos. Stam. 5-12, saepius 8. (Fol. opposita, simplicia, plerumque lobata, rarius impari-pinnata. Stipulae 0.)—Acerineae.

†† Semina albuminosa, solitaria. Fruct. drupaceus, abortu 1-loc. Germ. 3-loc, loc. 1-ovulatis, duobus subevanidis. Ovulum pendulum. Cal. persist. Pet. 5. Stam. 10, basi monadelpha. (Fol. alterna, rarissime opposita, simplicia, integra, saepe triplinervia. Stipulae 2 persist, intra axillam connatae in unicam saepe 2-ridam.)— Erythroxyleae.

II. Stamina 3 (an theris saepe 1-iocular.). Cal. 5-divisus, persist. Pet. 5. Germ. 3-loc, loeuL biseriatim pluriovulatis. Styli 3 connati. Carpella 3, v. abortu 2-1, samaroidea, 2-valvia, aut baccata, oligosperma. Sem. adscendent., exalbum. (Fol. oppos., simpl., indivisa. Stipulae parvae, deciduae.)—Hippocrateaceae.

B. Germen conrlatum ex ovariis 5 connatis, 1-ovulatis, ov. pendulis. Stigm. 5, sessilia. Carpella demum subdistincta, indehiscentia. Sem. exalbum. Cal. persist. 10-fid., lobis 5 interioribus callosis minoribus. Petala 0. Stamina 10, libera. (Fol. oppos., simpl., integra, 3-5-nervia, exstipulata.)—? Coriarieae.

Geographical Distribution. I have remarked above that this is a strictly tropical order, but principally confined to America, so much so indeed, that of 180 species described by DeCandolle in his Prodromus, only 5 are East Indian, 5 from Equinoctial Africa, 1 from the Cape and 1 from Arabia. Since that time considerable additions have been made to the Indian list, as there are about 20 enumerated in Wallich's list, and Blume has 6 from Java. To the Peninsular list nothing has been added since the publication of our Prodromus, except that the genus Ancistrocladus is ascertained to be unquestionably a native, as I have found it abundantly in the woods of Courtallum, and have also received specimens from Bombay : also from Maulmain and Ceylon. This therefore seems a widely diffused genus, but I have great doubts of the propriety of referring it to this order. The species of Malpighia here figured flowered in the garden of the Madras Horticultural Society, and is I believe of Chinese origin, if so, it is the first of the genus which has been found in the old world, but 1 doubt whether it can be admitted as a legitimate member of the genus.

Properties and Uses. Under this head little is known, and respecting the Asiatic members of the order nothing, except that they are highly ornamental twining shrubs, and merit a place in every shrubbery having ornament for its object, though so far as I have seen, they are nearly unknown in Madras.

Remarks on Geneva and Species. The genera of this order amounting, according to Meisner, to 26 in number, are distributed into three tribes, Malpighieae, Hiptageae, and Banisterieae, of the two last of these only, the Indian flora can with certainly be said to possess representatives. The native country of the Malpighia I have represented is uncertain. We no doubt received it from China, but have no means of ascertaining whether it is really a Chinese plant. Ancistrocladus is also referred to this tribe, but there is much reason to doubt whether it belongs to the order. Platynema and Hiptage, both certainly Indian plants, belong to the 2d tribe, and Hiraea equally so to the third. As these three are all old and weh known genera, it is unnecessary further to notice them here. Malpighia is also well known but not in this quarter, on which account I have been induced to give a figure illustrative of the tribe, if not of the genus; for in truth I rather think this plant will be found to constitute the type of a new genus, when examined by Botanists conversant with the tribe, which I am not, and therefore abstain from giving what may prove a needless generic name. It differs from Malpighia in its unequal filaments and anthers, as well as in its very unequal styles, but associates in the characters of its sepals, petals, and fruit; on which account I refer it. to that genus. The peculiarities of the stamens and styles sufficiently distinguish the species.

Ancistrocladus, as already remarked, is an extensively distiibuted genus, and when the species referred here, rather from similarity of habit than Botanical scrutiny, have been carefully examined, will probably be found to embrace more than one genus, and form the type of a new order intermediate between DipterocarpeAe and Malpighiaceae, but removed from both by the subinferior 1-celled ovary, with a solitary erect ovule. Vahl describes the species he saw (from Ceylon) as pentandrous. The Courtallum one has 10 stamens, one I have from Mergui, has 10 stamens, but united at the base by pairs like those of Hopea. This last associates in habit and in the form of its flowers, but differs in the ovary, which seems rudimentary. In all I have seen in fruit the sepals enlarge and become wing-like as in the Dipterocarpeae, not the carpels themselves as in some Malpighiaceae. Whether these different forms will ultimately be considered to form types of so many genera, and the whole a new order, future experience must determine, but in the mean time I do not think it can with propriety be referred to this order without much violence to existing affinities.

With Dipterocarpeae it is associated on the one hand, by the wing-like expansion of its sepals, when in fruit, by a more or less perfect union of its petals and filaments towards the base, by its twisted aestivation, and finally by its exalbuminous seed and thick fleshy exceedingly crumpled cotyledons : while on the other, it is removed by the ovary being inferior, not superior; one, not 3-celled, and with one erect, not several, pendulous ovules; and finally, by its scandent habit. The erect solitary ovule and scandent habit are the only points by which it approaches Malpighiaceae, while it is removed by the insertion of the petals being perigynous, by their being exunguiculate and occasionally cohering at the base, by their aestivation being twisted, not imbricative, and lastly, by the crumpled cotyledons. Much examination however is still required for the satisfactory elucidation of this very curious genus, but enough has been ascertained to shew that it is more nearly allied to Dipterocarpeae than to Malpighiaceae.

MALPIGHIA.

M. Heteranthera, (R. W.) Shrubby, ramous, leaves roundish, armed with spiny teeth, glabrous : peduncles axillary, jointed, furnished with two bracteal scales : petals unequal, fimbriated on the margin; stamens monadelphous at the base, two of them much larger : styles three, all distinct, two larger much bent, the other straightish and smaller : fruit composed of three unequal sized drupes.

Hab.—Uncertain, but supposed to have been brought to Madras from China.

This, as it appears in the Horticultural garden growing in a flower pot, is a small, very ramous, erect, leafy shrub, the leaves armed with sharp spiny teeth, like the Holly. The petals are plaited, unequal sized, fimbriated on the margin, usually pure white, but occasionally with a light rosy tinge. The fruit rarely arrives at maturity, but when it does seems to consist of three berries, scarcely adherent except at the base, one usually much larger than the other two, and that the one which bore the smallest style.

HIRAEA.

The two species of this genus established by Roxburgh and adopted in our Prodromus, unless distinguishable by the fruit alone, seem either but varieties of the same plant, or the one we had before us as H. indica is incorrectly described, as having the leaves glabrous on both sides. This I have ascertained through a number of newly preserved specimens recently received, the under surface of the leaves of which are covered with soft downy pubescence. The same I observe must have been the case with my original specimens when first collected, as there are still some remains of it visible. These two species, it would appear from this, can only be distinguished by the form of the wings of the carpels, that is whether they are oblong or elliptic. This may be a good specific character, but not the clothing. I have specimens of a third species, from Mergui, with carpels nearly answering to Roxburgh's description of H. nutans, though not exactly, as they are orbicular in place of elliptic ; the leaves are nearly oval, acute at both ends, and glabrous, which marks, when added to the diffuse few flowered panicles form a combination of characters which leaves no doubt of this one being distinct from all the Indian forms, These three species then may be thus distinguished by their fruit.

H. indica, carpels each surrounded with an oblong-linear entire wing.

H. nutans, carpels "surrounded with a large entire reticulate scarious elliptical wing." (Roxb.)

H. Merguienses, carpels surrounded with an orbicular thin transparent scarious reticulated wing.

In the two first the panicles are described as large, compound and clothed with appressed hairs, in the last rtiey are diffuse, glabrous, with few flowers, on long very slender jointed pedicels.

H. cordata, appears quite distinct from all these, but the fruit is as yet unknown.

The fruit of our H. indica is also unknown, and as it differs from Roxburgh's plant in having the under surface of the leaves rather thickly clothed with soft appressed pubescence', not glabrous, it may, when the fruit is found prove either Roxburgh's H. nutans, or a distinct species, but for the present must remain undetermined.

EXPLANATION OF PLATE 49.

1. Malpighia? heteranthera, (R. W.) natural size.

2. A partially dissected flower showing the glands of the sepals, a petal with its claw, and the unequal stamens and styles.

3. The same forcibly opened to show the union of the filaments, and more clearly the ovary, styles and stigmas.

4. Back and front views of a small anther.

5. The same of a large one.

6. The ovary 1-cell opened, to show the pendulous incurved solitary ovule.

7. The ovary cut transversely near the apex.

8. A mature fruit, natural size.

9. The same, one of the carpels cut transversely.

10. A seed removed and freed from its pulp, to show the rough reticulated testa.

11. The same opened to show the position of the seed.

12. Foliaceous cotyledons and the radicle.

13. A leaf — all, with the exceptions mentioned, more or less magnified.

EXPLANATION OF PLATE 50.

1. Hiptage Madablota, (Gaert.) natural size.

2. An expanded flower, the petals removed to show the relative position of the other parts.

3. The petals.

4. Anthers back and front views.

5. Ovary, style and stigma.

6. Style and stigma detached, and more highly magnified.

7. Ovary cut vertically.

8. Cut transversely, 3-celled.

9- A full grown fruit, natural size.

10. Cut transversely—with the exceptions mentioned, all more or less magnified.

MALPIGIACEÆ

MALPIGIA? HETERANTHERA (R.W.)

MALPIGIACEÆ

HIPTAGE MADABLOTA (GART.)