Illustrations of Indian Botany, Vol. 1/Polygaleae
XVIII.—POLYGALEAE.
This order which is very generally distributed over the globe, being found in every quarter of it, and in almost every kind of soil and climate, abounds in species, but is very limited in the number of genera, the latter, standing in the proportion of only about 1 to 19 or 20 of the former, on whole order. Among its species every form of vegetation is found, from the very minute annual scarcely 3 inches high, up to large sized trees. Many of these are milky plants, with round stems, and ex-stipulate, scattered, simple, entire, sessile, leaves, or having the limb attenuated into a short petiol. The flowers, which are sometimes solitary, often racemose, with the pedicels furnished with bractiee, are hermaphrodite and irregular in their form, often small, and inconspicuous, but showy in some of the Polygalas. The calyx is composed of 5 sepals, 3 exterior smaller; 2 interior and lateral much longer, and petaloid in appearance, (the wings). The corolla of 5 petals, but generally two of these are not developed, leaving only three, which often adhere at the base ; the anterior one larger than the others and somewhat boat-shaped; (the keel) the other two are alternate with the upper lateral sepals. Sometimes the whole number is complete, and then the two additional petals which are usually smaller, are placed between the keel and lateral petals, or between the anterior, and large lateral sepals, showing that it is the middle pair, or those alternating with the large petaloid sepals or wings, that are in the ordinary state of the flower suppressed. The keel is sometimes entire, and then, usually with a crest, sometimes 3-lobed, and without a crest, whence the crest is supposed to be the altered middle lobe of a 3-lobed keel. The stamens below are usually eight, ascending, combined into a tube adhering to the base of the petals ; sometimes 4 and distinct; when combined the tube is split opposite the upper sepal. Anthers clavate, erect, 1-celled, opening by a terminal pore, rarely, by a longitudinal slit. Disk sometimes large and forming a cup round the base of the ovary. Ovary free, compressed, formed of two united carpels, one anterior, and one posterior, usually 2-celled, with the placentae in the axis, but occasionally, 1-celled, from the suppression of one of the cells, and still more rarely, 1-celled, as in Xanthophyllum, with two opposite parietal placenta?. Ovulus solitary, or very rarely, from 2 to 6 in each cell, style simple curved. Fruit loculicidal, sometimes indehiscent. Seeds with a crustacious outer integument, furnished with a carunculus at the base, or an arillus : albumen, usually copious and fleshy ; sometimes reduced to a thin plate, or wanting as in Xanthophyllum : Embryo straight, radical next the hilum, cotyledons usually foliacious. The following further explanation of the nature of the irregularity of the flowers I extract from Dr. Lindley's Natural System of Botany, 2d edition.
"The calyx apparently consists of but three pieces, which are usually green, and like sepals in their common state ; but their real number is 5, the two coloured lateral petal-like bodies, sometimes lying within the apparent sepals, being in reality part of the series of the calyx. The corolla is mostly monopetalous, and, if carefully examined, formed of 3 pieces; namely, the keel and two petals, all soldered together. We have, therefore, an abortion of two petals, according to the laws of alternation : but this is not all; there is not only an abortion of two petals, but of these two which would, if present, be found right and left of the keel. The monopetalous corolla is, therefore, formed by the cohesion of the two posterior and the one anterior petal of a pentapetalous corolla, of which the two lateral petals are suppressed. The keel has an appendage of an anomalous character, called technically a crest, and often consisting of one or even two rows of fringes or divisions, originating not from the margin but from within it, and sometimes cohering in a common membrane at their base. Aug. de St. Hilaire has shown that this crest is nothing more than the deeply-lobed middle segment of a keel, with these lobes in such a state of cohesion that the central lobe is pushed outwards, while the lateral ones cohere by their own margins and with its back. The stamens are only 8, two therefore are suppressed : or in krameria 4, one being suppressed. I may remark, in addition, that the relative position of the fifth sepal and petal respectively, was first indicated by Brown." Denham 31.
Affinities. The opinions of Botanists, have always been much divided in regard to the affinities of this order, and the place it ought to occupy in the natural arrangement of plants Jussieu first placed Polygala among the Monopetalous orders, placing it at the head of his order Pediculares, but afterwards saw reason to change its place, and then ranged it among the Polypetalae. DeCandolle considering it more allied to Violarieae and Droseraceae, placed it after these orders. Bartling has placed it in his class "Rhoeadeae" along with Residaceae, Fumariaceae, Papaveraceae, Cruciferae, and Capparideae. Lindley prefers placing it in his alliance "Acerales" along with Aceraceae (Sycamore's) Sapendaceae, (soap-nuts) and OEsculacece, (horse chesnuts). The following exposition of the affinities of this order, is extracted from his work.
"Polygalaceae are stationed by DeCandolle between Droseraceae and Tremandraceae, and in the immediate vicinity of Violaceae. With the latter they are related on account of their hypogynous stamens, irregular flowers, and cucullate stigma; and with Tremandraceae on account of the caruncula of their seed. To Fumarieae they approach in the general aspect of their flowers; but if my theory of the structure of that order be admitted, their resemblance would not be so great as it appears to be. Leguminosae are, notwithstanding their perigynous stamens, an order with which Polygalaceae have great affinity : the irregularity of corolla is of a similar nature in both; there is in Leguminosae a tendency to suppress the upper lateral petals in Erythrina, as in Polygala; the ascending direction of the style and a cohesion of stamens are characters common to both orders. Many additional observations are made by St. Hilaire and Moquin—Tandon to the same effect. These authors, moreover, compare this order with Rutaceae; but they appear to have finally decided upon the vicinity of Sapindaceae being its true position; remarking that "the calyx of Sapindaceae is unequal the corolla very irregular, and the ovary of Schmidelia is usually 2-celled and 2-seeded like that of Polygala. Moreover, the greater part of the genera of that order have, with a calyx of five divisions, a corolla with four petals, and the place of the fifth is manifestly vacant. This suppression is not exactly the same as what is observed in the corolla of Polygala, where there is only 3 petals with 5 sepals; but the suppression has more analogy with what concerns the stamens, since with a quinary number in the calyx each order has eight antheriferous filaments."
Geographical Distribution. As already observed, this is most general, every part of the world being able to boast of some species, peculiarly its own. The genus Polygala is found in all climates, from the equinox to the polar circles, and in every variety of soil, from the burning sands and plains of Coromandel, to the Peat bogs of the northern mountains, and no where met with in greater beauty, than on the dry chalk hills of Kent. The other genera are more limited in their range. Salomonia has as yet only been met with in Asia, but extends from China to the Malabar Coast, being more or less met with in all the intermediate countries. Soulamia, is as yet only known to exist in the Moluccas. Xanthophyllum has a range nearly as wide as Salomonia, extending from Java, (whence Blume has three species which he had published under the generic name of Jackia) through Silhet, Ceylon, and Coromandel, to Malabar, but has not yet been met with out of Asia. Most of the other genera are American, but Muraltia is confined to the Cape of Good Hope.
Properties and Uses. Were the properties of the species of Polygala in accordance with virtues expressed in the name, (Poly gala 'Much milk,' in allusion to their supposed power of augmenting the flow of that secretion) truly valuable would they be in many situations, but we have no proof of their possessing such powers. Generally speaking, bitterness, combined in a greater or less degree with cathartic properties, have been found in those species which have been subjected to trial, especially Polygala amara, on which account, it is esteemed in chronic bowel complaints after active inflammatory symptoms have subsided. But the diseases for the cure of which they have attained their greatest repute, are those of the chest, requiring expectorants, on account of their action on the mucous membrane of the bronchi. In such cases, if inflammatory symptoms exist, they must in the first instance be reduced by bleeding. The senega, or snake-root of America, (Polygala senega) is the species which has attained the highest repute for its medical properties, and especially as a remedy in diseases of the chest, but notwithstanding it has been highly extolled in such cases, and no doubt in many instances deservedly, there is still much uncertainty as to its real merits. Among the aborigines of America, it is administered in cases of snake bite, and it was from observing its effects in relieving oppression of breathing in such cases, that analogy led Dr. Tennant to recommend its employment in deseases of the chest. A species met with on the Himalaya mountains P. crotalarioides is used by the inhabitants of these hills as a remedy in snake bite in like manner as P. senega, is by the Americans. Such being the case, it appears somewhat remarkable, that of all the long list of Indian species, about 20 in number, that not one of them, with that exception, is mentioned as being employed in native practice, and yet, I cannot help thinking, that some at least of the Indian species, enjoy properties analogous to those found in both the European and American ones.
A peculiar vegetable principle, called Senegen has been discovered by one chemist, (Gehlen) and a different one by another, (Reschier) which he has called Polygaline, but it is still uncertain whether they are not the same. A third (M. Folchi) has procured a substance, which he calls Polygaline, under the form of brilliant pale coloured scales at first insipid, afterwards acrid and burning to the taste, insoluble in distilled water, and but sparingly soluble in alcohol. M. Dulong on the contrary, procured one, deliquescent and very soluble in water and alcohol. M. Peschier states that he obtained from 6 ounces of the root 100 grains of an alcaline substance, united with a new acid, which he has called acide Polygalinique. The Krameria or Ratany root remarkable for its astringent, properties and for its extensive employment by preparers of Port wine in Britian, is derived from another genus of this or a nearly allied family. The species of Xanthophyllum are trees that furnish timber of considerable size, and being besides handsome flowering plants, deserve a place in the garden, as does Polygala arillata a very handsome flowering shrub, not uncommon on the higher hills of this country. The properties of both Xanthophyllum and P. arillata if they possess any, are unknown. It seems to me desirable to remove the latter from the genus Poly gala, from most of the species of which it differs very widely in habit and in the arillus which covers the whole of the seed.
Remarks on Genera and Species. Three genera only, of this order, have as yet been found in the Indian Peninsula, viz. Polygala, Xanthophyllum, and Salomonia. The first of these, is a very old genus, has been long known as a native of India, but of which it appears Dr. Roxburgh knew only 'Z peninsular species, these have now been increased to 14 and Dr. Wallich and Mr. Royle mention several others, not met with in this part of India. Xanthophyllum is a genus originally established by Roxburgh for two Silhet trees, but is now found to extend nearly to the southern extremity of the peninsula, as I have several species from Courtallum, and one from Ceylon. It is also found in Java, whence Blume has 3 species to which he has given the name of Jackia, not knowing, that the genus had been previously named by Roxburgh. The genus Salomonia, originally established by Loureiro to receive a small Chinese plant, has recently had considerable additions made to it. Two have been found in Nepaul, three in Ceylon, and one in Malabar. The last, having been discovered for the first time in 1835, the genus has not yet found its way into our catalogue of peninsular plants, on which account I have availed myself of the present opportunity of making it known. The species of Polygala here represented, was selected on account of its being new to the peninsular flora, and under the supposition that it is a new species. On this last point however I have still some doubts, not but that my plant appears more distinct from P. perseearicefolia as figured by Wallich (Plant, rar. tab. 184) than many of the other allied species of the genus which are kept distinct, but because, I find they have a strong tendency to vary in their forms. I was particularly struck with this disposition while examining a very large series of specimens of P. Javana, presenting almost every form of vegetation and outline of foliage, but all agreeing in two points, the large wings of the calyx, and in having a curious 2 lobed membranous appendage, or arillus pendant from the carunculus. In like manner P. Heyneana has three, smaller, but in other respects similar, appendages hanging like flaps, nearly the whole length of the seed, from its carunculus, by which a number of sufficiently distinct looking specimens were with certainty associated. None of the other species possessed an equally certain guide by which to bring varying forms together, but from what I have observed in these two, I feel but little hesitation in concluding, that in some instances mere varieties are raised to the rank of species.
The genus Salomonia is distinguished from Polygalaby the absence of the large wing-like interior sepals; its 5 sepals being all nearly equal, by having four, not eight, stamens with the filaments united their whole length; and lastly, by the capsule being furnished on the margine with long tooth-like bristles, in place of being naked, or ciliated. Two species are introduced into the accompanying plate, one from Ceylon, recently discovered, and the other from Malabar.
The genus Xanthophyllum differs from the rest of the order in having symmetrical flowers, except the stamens, and exalbuminous seed. Here in place of three petals firmly united at the base into one, there are 5 petals, corresponding in number, and alternate with the lobes of the calyx, but the stamens retain the unsymmetrical character of the order. It differs further from the character of the order in having the placentae parietal in place of in the axis of the ovary. The species of Xanthophyllum here figured I at first doubted, whether to consider a narrow-leaved variety of one of Roxburgh's species, or distinct from both ; the latter I now think the more correct view ; partly on account of the difference of appearance of this plant, but much more on account of the difference of structure which its ovary presents. In X. flavescens, Roxburgh describes and figures the ovary as having two tubercles rising from the base, each bearing two erect ovules, and in his X. virens, he represents the placentas as forming two projections, one from each side of the ovary extending its whole length, and each bearing from 4 to 6 ovules! In my plant, I find only 4 ovules, as in flavescens, but differently situated, one namely from each extremity of each placenta, one ascending the other pendulous. On this account it approaches more nearly to X. virens, but in that species each placenta bears from 4 to 6 ovules in two rows. I may here observe that in our Prodromus we have fallen into an error in adopting the name flavescens, for the only species it contains. It is most true that in its general aspect, our plant corresponds with Roxburgh's flavescens, even to the colour of the leaves but it differs in the structure of the ovary, the principal point of difference between Roxburgh's' two species. From X. virens, both the present species and flavescens of the Prodromus differ in the absence of a glandular enlargement of the veins on the lower surface of the leaves and in changing to yellow in drying. The very distant stations of the two plants, tend, still further to confirm the opinion that they are distinct. On this point however, T refrain from offering any decided opinion, as 1 have not seen a specimen of the original X. virens. Among my specimens from Courtallum and Ceylon, there are five distinct forms, which may be thus distinguished and named—1st, the one here figured, X. angustifolium. 2d, one with subsecund spicate racemes, elliptic, shortly acuminated, green, leaves; ovary with four ovules, 2 erect and 2 pendulous, X. Roxburgianum. 3d, one with hard coriacious reticulated, glabrous, acuminated leaves, undulated on the margin ; ovary with four transverse ovules, X. undulatum. 4th, the form described in our Prodromus under the name of X. flavescens, but which I now consider quite distinct from Roxburgh's plant, X. Arnotlianum: and lastly, one from Ceylon, with oval leaves, ending in an abrupt, rather long pointed, acumen; the ovary 4-ovuled, the ovules attached to the base, ascending ; probably the true X. flavescens of Roxb : the figure of which it greatly resembles.
POLYGALA.
P. Wallichiana. (R.W.) Glabrous, erect, ramous : leaves narrow, lanceolate, obtuse: racemes axillary, or from the forks of the branches, many flowered : wings from broadly ovate to orbicular, longer than the capsules : capsule margined, glabrous : seeds black, densely covered with white hairs, carunculus white edentulate.
P. persicariaefolia. Wall. List 4185, c.
A native of Alpine districts, frequent on the Pulney hills, where the plant attains a much larger size than the one here represented, bearing fewer but longer racemes.
This differs from the plant figured by Wallich, in being perfectly glabrous, diffusely, ramous in having the racemes invariably springing from the branches, in place of terminal as in his plant, sometimes they are axillary, sometimes supra-axillary, and not unfrequently from the forks of the branches. The flowers appear much smaller than in his. It differs from DeCandolle's plant in being glabrous, not pubescent, and in having glabrous, not ciliate capsules; From Dons, P. Buchanani, it differs in its ramous habit, and in being every where glabrous. The plant here figured is, 1 find, equally a native of the Himalayas, and of the southern mountains, as I have a specimen from Simla, procured from a very extensive and beautifully preserved collection of plants formed, while there, by Lady Dalhousie.
SALOMONIA.
Calyx 5-sepaled, sepals about equal. Petals 3, united below into a tube, cleft longitudinally on one side. Stamens 4, filaments united their whole length, and adhering near the base to the tube of the°corolla. Anthers 4. Capsule compressed, bristle-toothed on the margin, 2-lobed, 2-celled, with a single pendulous seed in each cell. Seed compressed, glabrous, sublenticular black, testa crustacious, brittle. Embryo large, straight, enclosed in albumen. Cotyledons foliacious, radicle pointing to the hilum.
Small herbaceous plants; leaves alternate; racemes terminal; flowers minute, purplish, each furnished with a bractea.
Mr. Don characterizes this genus as exalbuminous, and with an inverse embryo, in both of which points, it appears to me he is mistaken ; the albumen being rather copious in S. obovata, and the embryo erect with respect to the seed, though inverse with reference to the plant.
1. S. obovata. (R. W.) Erect, ramous: leaves sub-sessile, glabrous, obovate obtuse, or spathulate below; above, from sub-orbicular to cordate : spikes elongated: capsules bristle-toothed on the marline.
Malabar Coast and Ceylon.
My specimens from Malabar scarcely exceed three inches in height, but are very ramous, some that I have from Ceylon of apparently the same plant, are much larger, but less branched; in all other respects they correspond. Perhaps the species is too nearly allied to S. oblongifolia D.C. which however seems distinct.
2. Salomonia cordata. (Arnott) Ramous, leaves sessile, cordate, ovate, glabrous on the sides, ciliate on the margin ; spikes elongated: capsules crestato-pectinate. Arnott.
Sea Coast Ceylon.
All the species from southern India are coast plants. Mr. Arnott inadvertently quotes the mountains of Ceylon as the station of the two species seen by him, but I am informed by Colonel Walker, who communicated the specimens, that that is an error, as he got them both in the neighbourhood of Colombo.
XANTHOPHYLLUM. (Roxb.)
1. X. angustifolium. (R. W.) Leaves narrow lanceolate, obtuse, glabrous, longer than the axillary and terminal racemes : ovary l-celled, 4-ovuled, two ascending from the base, and two pendulous from the apix of the cell : Fruit.
Courlallum in thickets. The leaves of this species which are hard and coriacious do not turn yellow in drying but are of a pale brownish colour.
2. X. undulatum. (R. W.) Leaves elliptic, oblong, acuminated, undulated on the margin, coriacious : Ovary l-celled, 4-ovuled, ovules transverse.
Courtallum. This species agrees so much in the texture and colour of the leaves as well as in the character of the ovary, with the preceding that I rather doubt the propriety of separating them, but the undulated margin, the long pointed acumen, and the much larger size, in all its parts, of the one than the other, fully warrant me, 1 think in doing so.
3. X. Roxburgianum. (R. W.) Leaves broadly elliptical, acuminated : racemes axillary and terminal, shorter than the leaves, subsecund : Ovary l-celled, 4-ovuled, two ascending, and two pendulous; Fruit.
Courlallum and Shevagerry hills in woods and thickets.
This species which differs very widely from the preceding in appearance, seems, judging from the specimens alone, to be a diffuse or scandent shrub. The leaves retain their green colour in drying.
4. X. Arnottianum. (R. W.) leaves elliptic oblong, with a short blunt acumination : under side with two pores at the base : racemes axillary and terminal : Ovules 8 — 12; attached by pairs to two lateral placenta? : fruit globose, one seeded. X. flavescens W. and A. Prod, not Roxburgh.
Woods about Courtallum and elsewhere.
5. X. flavescens? Roxb. Leaves elliptic oblong, with a longish fine pointed acumination ; numerous dores scattered over the under surface : racemes axillary and terminal, shorter than the leaves : Ovules 4, erect, attached near the base of the ovary. Ceylon—Communicated by Colonel Walker.
This is a handsome species, and is perhaps distinct from Roxburgh's flavescens though corresponding with it, in (he character of the ovary and ovules; but while unacquainted with the original species, I feel averse to add to the difficulties of a sufficiently difficult genus, by adding doubtful species. The pores on the under surface of the leaves are peculiar, from the circumstance of their being scattered all over them and not as usual confined to the base.
EXPLANATION OF PLATES 22 and 23.
22.— POLYGALA.
A. I. P. Wallichiana—natural size. 2. Flower opened, showing the calyx and corolla. 3. The same, the corolla drawn back to shew the stamens, ovary and style. 4. A stamen. 5. Style and stigma. 6. Capsule. 7. The same split vertically, showing the seeds in situ. 8. Seed. 9. Embryo. 10. Seed of Poly gala Heyneana, showing the pendulous lobes of the carunculus. 11, 12. Back and front views of P. Javana, showing the two large lobes of its carunculus — all more or less magnified.
B. 1. Salomonia obovata—natural size. 2. Calyx and corolla. 3. The same, the petals and stamens separated, showing the ovary, style and stigma. 4. Capsule- 5. The same opened, showing the seed. 6. A seed — all more or less magnified.
C. 1. Salomonia cordata—natural size. 2. A leaf magnified. 3. Flower opened, and the petals and stamens removed to show the ovary, style and stigma. 4. Capsule. 5. Capsule opened. 6. Seed. 7. The same cut transversely. 8. Embryo removed-all more or less magnified.
23.— XANTHOPHYLLUM.
I. X. angustifolium—natural size. 2. Flower. 3. Petals removed, showing the stamens. 4. Stamen separated. 5. Ovary. 6. Ovary opened, showing the position of the ovules—all more or less magnified. 7. Young fruit—natural size. 8. The same opened showing that all the ovules but one have aborted magnified. 9. Ovary of X. Arnottianum laid open, showing one placenta with its attached ovules. 10. Ovary of X. flavescens ? showing the four erect ovules— both, magnified.
POLYGALEŒ.jpg)
A. POLYGALA WALLICHIANA R. W.
B. SALOMONIA OBOVATA (R.W.) C. SALOMONIA CORDATA. ARN.
POLYGALEŒ.jpg)
XANTHOPHYLLUM ANGUSTIFOLUM. (R.W.)