Illustrations of Indian Botany, Vol. 1/Balsamineae

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Illustrations of Indian Botany, Vol. 1 (1840)
by Robert Wight
Balsamineae
4500777Illustrations of Indian Botany, Vol. 1 — Balsamineae1840Robert Wight

XLIV.—BALSAMINEAE.

A small order of tender herbaceous succulent plants with round branches ; alternate, or opposite, exstipulate, serrated, simple leaves : usually confined to marshy grounds, or to moist shaded situations, and of most frequent occurrence in warm humid climates within the tropics. The flowers are bisexual, irregular, axillary, solitary or fascicled, or racemose, pedicelled; white, red, or yellow.

" Sepals 5, or by abortion 3, irregular, deciduous, with an imbricated aestivation ; the two exterior opposite, lateral, somewhat unsymmetrical, with a valvate aestivation, but giving way for the projection of the spur of the odd sepal ; the odd sepal spurred, symmetrical, with an equitant aestivation in the bud, looking towards the axis of the axillary racemose or umbellate inflorescence, containing honey; the two inner sepals very small, sometimes scale shaped, sometimes unsymmetrical, larger, orbicular, always coloured, appearing at the side of the flower, which is opposite to the spurred sepal, and at the base of the odd petal; (usually altogether abortive in Balsamina). Petals either distinct or a little adhering, 5, combined into 3, irre- gular, deciduous, alternate with the sepals ; the odd petal regular, placed between the inner scale-like sepals, in front of the bract, wrapping up a great part of the remainder of the flower in aestivation ; the four remaining petals unsymmetrical, united more or less on each side of the flower in pairs ; their two larger lobes next the spur, their smaller next the odd petal ; aestivation convolute. Stamens 5, symmetrical, alternate with the petals ; those alternate with the odd petal longer than the others. Carpels 5, alternate with the stamens consolidated into a 5-celled ovary. (Roper abridged). Stigma sessile, more or less divided in 5, cells 5, two, or many seeded. Fruit capsular, with 5 elastic valves, and 5 cells formed by membranous projec- tions of the placenta, which occupies the axis of the fruit, and is connected with the apex l>y 5 slender threads ; sometimes succulent and iudehiscent. Seeds solitary, or numerous, suspended ; albumen none, embryo straight, with a superior radicle and plano-convex cotyledons."

This character is copied from Dr. Lindley's Natural System of Botany, and explains the views of Professor Roper, of Bale, of the structure of the flowers of this family which differs from that of Professor Kunth adopted in our Prodromus. These eminent Botanists take very different views of the construction of the flowers of this order of plants. Their differences may be thus explained — Kunth proceeds from a full grown flower, the spur of which is pendulous and appears on the same line with the bractea, that is, remote from the axis of the plant, (a line drawn through the stem,) hence, as the flower han^s on the stalk the spur is the lowest part, and if so placed that the axis of the flower, or a line drawn through its centre, is vertical will look towards the horizon in place of towards the axis of the plant.

Roper on the other hand commences his examinalion with the flower-bud, in the early stages of its growth, the spur in place of being the lower part of the flower next the bractea and remote from the axis is then on the upper part, and next the axis, showing clearly, that, in the progress of the flower towards maturity, the pedicel acquires a twist which changes, with respect to the axis, the relative position of all its parts. For the correctness of this last view the analogy of Orchideae may be adduced, in nearly the whole of which family, the pedicel becomes similarly twisted placing the lip of the flower, which in the hud is above, on the lower part. According to Kunth's view, the spur is the low^r or odd sepal, the lar^e upper segment of the flower two sepals united, and the two small green ones on either side are the lateral

sepals, making a total of 5 sepals : while the two interior lobed petals he considers four petals united two and two, the fifth or odd petal, required to make up the normal number of 5 he supposes aborts, but ought to be placed on the upper part of the flower, opposite the large leaf which he supposes is formed by the union of the two upper sepals. Roper commences his examination with the young bud and finds the spur on the superior aspect next the axis, this therefore he considers the upper or odd sepal, the two green leaves the lower or exterior sepals, while between them and the lower leaf of the expanded flower, he finds two small scale-like sepaloid bodies, which however often abort, these he considers the inner pair of sepals. Kunth's upper united pair of sepal>, which at this period are on the lower part of the flower opposite the spur he considers the odd or anterior petal, and the lateral lobed ones as double petals, thus making, up the number 5, the regular number of the genus. To trace the different stages of this theory which as being most consonant with the analogy of the rest of the vegetable kingdom, and especially with the Orchideae, appears to be the true one, it is only necessary to invert a flower of a balsam so as to place the spur uppeimost as it is in the bud when the whole becomes evi- dent. We then see the odd sepal above and the odd or anterior petal below, with one pair of the lateral sepals, (the other pair sometimes present, very small, but oftener absent from abor- tion) and the two pair of the lateral petals, but usually united below into a single 2-lobed petal.

In support of Kunth's view it may be urged that the interior petal of Roper is more ana- logous in texture to a sepal than a petal. This however is not an argument of much weight. In a practical point of view the difference is not of much consequence, since in describing the organ in question, for the purpose of deducing specific characters, it seems not to matter much, whether we call it a superior sepal or an inferior petal, so long as the part meant is clearly un- derstood.

Affinities. I mentioned above that this order is considered by some Botanists nearly allied to the two preceding and to Oxalideae, but that others separate Lineae from the group on account of its wanting the gynobasi. This structure, the essential character of which is " Carpels seldom or never exceeding 5, always in a single whorl diverging at the base, and separated by the interposition of a conical gynobase, which throws them into an oblique posi- tion" (Lind.) is not so evident in the Balsamineae as in Geraniaceae, but still when sought for in the ovary, can be made out especially in the genus Hydroeera, where it is very distinct. Notwithstanding this mark of relationship Bartling does not see any affinity between these orders, and remarks that unless somewhat allied to Fumareaceae it is far removed from all other orders, and therefore places it at the end of this work along with some others, the place of which ; n the series he is uncertain about.

The Tropeoleae, or Nasturtium tribe, on the other hand, which other Botanists consider only a sub-order or section of Balsamineae, Bartling places in his class Malpighinae near Sapindaceae, while Mr. Don thinks them allied to Capparideae. Bartling's view is, I think, nearer the truth than Don's, as there is certainly many points of similarity between the orders though but little affinity.

Geographical Distribution. As affording the most complete view of this part of the subject, so far as I know, yet published, I shall here introduce some remarks which I formerly published in the Madras Journal of Science, merely adding, that, since they were written I found several species, not noticed in these introductory remarks, on the higher ranges of the Pulney mountains, and have by me drawings of seven species collected on the Neilgherries by Mr. G. Gough, several of which are new.

"Of this genus, now embracing nearly one hundred species, Linnaeus only knew seven or eight; and most of these from indifferent figures. In 1805 when Persoon published his Synopsis, ten only were known; to these only six had been added in 1819, when Roemer and Schultes published the fourth volume of their Sysfema FegelabiUum, and one of the six " sine definitione." In 1^24, Profess >r DeCandolle published the first volume of his Prodromus, and extended the catalogue from sixteen to thirty-one, excluding the undefined one, thus doubling the former number: of these, twenty-four are Indian, nearly all the new ones being derived from Dr. Wallich's Nepaul Collections. In 1830-3 1 , Dr. Wallich named in his list no fewer than forty-seven Indian species. Since that time Mr. Royle informs us, {111 usltalions page l) that his collection contains several not in Wallich's list, and Mr. Arnott writes me that he has recently described sixteen new ones from Ceylon. To these last, my excursions on the Courtallum and Shevagerry hills have added about as many more. Of the Courtallum ones, those only of which drawings were made, are introduced into this paper; not having, either specimens or sufficiently perfect notes, to enable me to define the rest.

It is a curious, and to me an inexplicable fact, that a genus so strikingly Indian, and associating such a host of species, should have been so little known to Roxburgh. He only describes three in his Flora, though I am sure I speak within bounds, when I assert that the countries, whence he derived the materials for his work, will be found to present an assemblage of not fewer than one hundred species. It is no doubt an eminently alpine genus, delighting in a cool and moist climate ; hence it is unknown on the plains of Coromandel, though not unfrequent in Mysore, but, so far as I have seen, only abounding, in the Peninsula, on the higher hills participating in the western monsoon, which enjoy, during the hot months, a moderate range of temperature, with a very humid atmosphere. Some, (how many is not yet known,) are found during the monsoon on the Malabar coast, little elevated above the level of the sea, but, except in Tanjore, I have not seen one of the order on the plains eastward of the ghauts, beyond the influence of that monsoon: and the only one found there, is Hijdrocera trijiora, which grows, but is not common, in its ditches and swampy grounds, during the cool season, and is the only place where I have yet seen it.

This peculiarity of distribution may account for his not having met with Peninsular species, as he was but little in the southern provinces, and perhaps they are not found in the eastern range of the northern ghauts : but, twenty-two of the forty-seven species named by Wallich, are from Silhet, Pundooa and Nepaul, from all of which places Roxburgh procured plants, and one of the three he describes is from Silhet. A moist climate and moderate temperature are the circumstances most favourable, if not indispensable, to their production ; hence we find twenty two, of the remaining twenty-five species named by Wallich, natives of the Peninsula, but confined to the ghauts and Mysore where these contingercies meet. This fact was first noticed by Mr. Royle, who, after remarking the nearly equal division of the forty-seven species between the frontier mountains of Bengal and the Peninsula, adds, " a singular equality of numbers, seeing that we have hitherto found Peninsular and South of India genera confined to the base of the mountains, and if found existing on them, generally only as single species; but here we have them in equal numbers, some of them extending to an elevation of seven thousand feet.

" This anomaly can only be explained, and a stronger fact cannot be adduced in its confirmation, than that the moisture and moderate temperature of the rainy season in the hills (for it is at this season only that they are found) is as favourable to their growth as the hear and moisture of the Peninsula. I have never met with any in the plains of India ; but have heard from travellers that they are abundant in Central India, whence we may expect some new species, as well as from thp Neilgherries."

The facts which I have mentioned regarding the distribution of the Peninsular species, go to pi-ove, that heat and moisture are not the circumstances most favourable to their production here, but moisture combined with a moderate but equal temperature. At Courtallum for example, whence I have eleven or twelve species, they most abound in shady places on the tops of the hills, with a mean temperature during the season of their greatest perfection, not exceeding 70°, if so much. At Shevagerry, about fifty miles north of Courtallum, 1 found five, out of seven species, on the highest tops of the mountains ; none of the five u'«tder 4,000 feet, and three of them above 4,500 feet of elevation ; the mean temperature, as deduced from twenty observations, continued through four days, at an elevation of 4,100 feet, being 65° of Fahrenheit's scale. The two found at a lower elevation, were both either growing in the gravelly beds of streams, or immediately on their banks ; the temperature of which was ascertained to be 65°, while that of the air at noon was only about 75 a , a temperature, I presume, but little above that in which they delight on the Bengal frontiers. There is one other point, respecting the effect of climate on plants of this genus, to which I wish to call attention, as it may ultimately prove useful to any one who may again attempt to subdivide it, and is, in the mean time, in a physiological point of view, exceedingly curious. It is, that most of the species from the colder regions of the Himalaya mountains, correspond with the European I. noli tangpie, in the form- and dehiscence of their capsule, that is, they split from the base, rolling the segments toward* the apex, while those of the warmer regions split from the apex and roll their segments towards the base. This difference of habit between those of India proper and the Himalayan forms, is well worth}' of notice, as it shows, that the affinity which exists between the flora of the latter and that of Europe, is stronger than between it and the Indian, and extends to even this most purely tropical genus.

The innate power which plants enjoy of selecting the soil and climate in different countries, however remote, most suitable to their perfect development, and which the preceding remarks have shown to be so eminently possessed by those of this order, may, when the subject has been more studied and is better understood, prove of immense benefit to the scientific cultivator.

Taking for an example the genus Impatiens, we may at once infer, that herbaceous plants growing where its species abounds, and arriving at maturity about the same time, may be transferred to any other locality, where they are equally prevalent. Thus the associates of I. nolitangere, insignis, racemosa and bicolor, might be mutually interchanged ; while the neighbours of I. reticulata, pubertda, &c. might be made to change places with those of I. fasciculata, grandis, and many more, with every prospect of success. The limits to which this rule may be extended are as yet totally unknown, and cannot be estimated, until plants are studied not as insulated individuals, but in connexion with the soil, climate, aspect, exposure, &c. in which they are observed to arrive at the greatest perfection. This is a study which the scientific Botanist pursues in its relations to the physiological peculiarities of plants, but to the cultivator, it becomes one of much deeper and more engrossing interest, as the success or failure of vast speculations may depend on his acquaintance with, or ignorance of, the external agents which act on the objects of his culture — whether for their benefit or their injury.

Properties and Usrs. Under this head there is little room for remark. One species, Impatiens noli tanpere, which derives its name " Noli tangere" from its acrimony, is said to be so powerfully diuretic that it is capable of producing a diabetes. This I think may be doubted. Applied as a cataplasm on the hypogastrium, it equally acts on the kidneys. Neither this nor, I believe, any other species of the genus is now used in medicine. As however species greatly abound in India the subject, of their medical properties, seems not undeserving of enquiry among those favourably situated for conducting such investigations.

Remarks on Genera and Species. The genera of this order are few, amounting as yet, I believe, to only two, viz. Impatiens and Hi/drocera — the former distinguished by the irregularity, caused by suppression and union of parts of its flowers, the latter, by having them quite regular with a drupacious 5-celled fruit — The species on the other hand, are numerous, and when characterized from dry specimens the most difficult to distinguish, though with recent ones less so than those of many other genera. This arises from the tender succulent nature of the plants causing the flowers, the part from which the best characters are derived, to become so matted together in drying, that it is quite impossible to separate them afterwards in such a manner as to show their forms.

The genus Impatiens affords several excellent marks for the distribution of its species into sectional groups : for example, in some the valves of the capsule roll from the base to the apex ; in others from the apex to the base : this character may serve to divide them into two subgenera — Impatiens and Balsamina. Of Balsamina some species have alternate, others opposite leaves: these differences form the first subdivision of them. Of the alternate leaved section again, so many have ancillary, solitary, one-flowered pedicels ; while others have many flowered peduncles. Of the latter or opposite leaved division, the flowers are either solitary in the axils, or they are fascicled. To these leading divisions several other easily observed subdivisions can be made, which, so vastly facilitate the discrimination of the species, that those of this, generally supposed most difficult genus, become among the easiest to distinguish of those embracing so large a number.

The fullest advantage has been taken these sectional characters, in our account of the genus in the Prodromus as well as in the respective contributions towards the elucidation of its species by both Dr. Arnott and myself, published in Hooker's Companion to the Botanical Magazine, vol. 1st, and in the Madras Journal of Science. To these sources I am under the

necessity of referring, having already exceeded my space here. The species figured, is a Ceylon plant, first discovered and named by Mr. Moon : Colonel and Mrs. Walker afterwards found it, and for the figure, I am indebted to the kindness of that accomplished lady.

IMPATIENS.

§. Leaves alternate, pedicels axillary, solitary, or aggregated, one Jloicered.

I. repens, (Moon's Catal.) diffuse, procumbent, leaves alternate, suborbicular-cordate, hairy, pedicels axillary, longer than the leaves, flowers large, (yellow) upper sepals orbicular, lower cuculate ending in a thick short spur, tumid at the apex, lateral petals deeply 2-lobed, lobes irregular, the upper ones larger, ovary hairy.

In shady vegetable soil, Four Korles. Moon.

Munronii, (R. W.) Erect, sparingly ramous, leaves crowded towards the summit, ovate, slightly serrated, acute, hairy on b th sides, pedicels axillary, solitary, one (always ?) flowered, furnished near the base with a bractea, longer than the leaves : lateral sepals ovate, toothed at the apex, posterior ones concave, helmet- shaped, and furnished with a foliaceous crest, lower one conical, terminating in a long hooked spur, lower lobes of the petals twice the size of the upper ones.

Neilgherries on moist rocks by the road side near Sis- para. Munro and Gough.

The affinities of this species are clearly with my I. auriculata and /. viridiflora, but it certainly differs from both. The bractea near the base of the petiol seems to indicate that the peduncles are occasionally

and perhaps often 2-flowered, when exposed to much moisture and growing luxuriantly.

§. Leaves alternate, peduncles many flowered.

I. Goughii, (R. W.) Erect, ramous, every where glabrous, leaves ovale, serrated, short petioled, aggre- gated towards the summit of the branches, peduncles filiform, axillary, umbellately, 4-6 fl- wered, often three or four times the length of the leaf, viscid, flowers small, lateral sepals minute, subulate, superior ones broad, obcordate mucronate, lower, much shorter than the petals, acute, spur shorter than the flowers, coni- cal, slightly incurved — anterior lobes of the petals much larger than the posterior, capsules glabrous.

Neilgherries on damp rocks by Pekarra river. Gough.

The present species is evidently intermediate be- tween /. uncinata and I. campanulata, having a shorter spur than the former, and longer than the latter, but judging from the specimens is much smaller than either. This however is a mark of no value, as the same species in some situations may be quite diminu- tive, while in others it attains a great size.

I have dedicated these the only new species yet re- ceived from the Hills to the two young Botanists who, in company, explored much of them that had not pre- viously been examined.

EXPLANATION OF PLATE 61.

1. Upper sepal front and side views, 4. Ovary and stamens.

2- 2. Anterior sepal with its spur. 5. Stamens removed.

3- 3-3. Petals different views. 6. Ovary and style,

BALSAMINEÆ

IMPATIENS REPENS. (MOON.)