An introduction to physiological and systematical botany/Chapter 13
CHAPTER XIII.
DIFFERENT KINDS OF STEMS AND STALKS OF PLANTS.
Linnæus enumerates seven kinds of Trunks, Stems, or Stalks of Vegetables. These are necessary to be known, for botanical distinctions, though some are more important than others, both in that respect and in a physiological point of view.
1. Caulis. A Stem properly so called, which bears, or elevates from the root, the leaves as well as flowers. The trunks and branches of all trees and shrubs come under this denomination, as well as of a great proportion of herbaceous plants, especially annuals.
The Stem is either simple, as in the White Lily, or branched, as in most instances. When it is regularly and repeatedly divided, and a flower springs from each division, it is called caulis dichotomus, a forked stem, as in Chlora perfoliata, Engl. Bot. t. 60, as well as the common Mouse-ear Chickweeds, Cerastium vulgatum, t. 789, and viscosum, t. 790.
Though generally leafy, a Stem may be partially naked, or even entirely so in plants destitute of leaves altogether, as the Creeping Cereus, Cactus flagelliformis, Curt. Mag. t. 17, various exotic species of Euphorbia or Spurge, and the whole genus of Stapelia. In Orobanche, it is scaly, squamosus.
With respect to mode of growth, the Stem is
Erectus, upright, as in Yellow Loosestrife, Lysimachia vulgaris. Engl. Bot. t. 761.
Procumbens, procumbent, Wood Loosestrife, L. nemorum, t. 527.
Repens, creeping, Creeping Loosestrife, L. Nummularia, t. 528, and Creeping Crowfoot, Ranunculus repens, t. 516.
Adscendens, ascending obliquely without support, as Panicum sanguinale, t. 849.
Prostratus, prostrate, or Depressus, depressed, when it lies remarkably flat, spreading horizontally over the ground, as in Coldenia procumbens; also Coronopus Ruellii, Swine's-cress. Eng. Bot. t. 1660.
Reclinatus, reclining, curved towards the ground, as in Ficus, the Fig, Rubus, the Bramble, &c.
Radicans, clinging to any other body for support, by means of fibres, which do not imbibe nourishment, as Ivy, Hedera Helix, Engl. Bot. t. 1267, Vitis quinquefolia, Sm. Insects of Georgia, t. 30. Bignonia radicans, Curt. Mag. t. 485.—Linnæus, Philosophia Botanica 39, has expressed this by the term repens, but has corrected it in his own copy. Still he does not distinguish between these plants, and those whose stems throw out real roots, which last only are justly called creeping whether they grow on the ground, like those above mentioned, or on other plants like Cuscuta, Dodder, Engl. Bot. t. 55 and 378. See p. 95.
Scandens, climbing; either with spiral tendrils for its support, as the Vine, Vitis, the various species of Passion-flower, Passiflora cærulea, Curt. Mag. t. 28, alata, t. 66, &c. and Bryonia dioica, Red-berried Bryony, Engl. Bot. t. 439; or by adhesive fibres, as in the preceding paragraph.
Volubilis, twining round other plants by its own spiral form, either from left to right, supposing the observer in the centre, (or in other words, according to the apparent motion of the sun,) as the Black Bryony, Tamus communis, Engl. Bot. t. 91, the Honeysuckles, Lonicera Caprifolium, t. 799, and Periclymenum, t. 800, and the Polygonum Convolvulus, t. 941; or from right to left, contrary to the sun, as the Great Bindweed, Convolvulus sepium, t. 313, the French Bean, Phaseolus vulgaris, Ger. em. 1212, fig. 1, &c.—Figures of plants being sometimes reversed by the engraver, in that case give a wrong representation of the circumstance in question, witness Lonicera Periclymenum in Curtis's Flora Londinensis, fasc. 1. t. 15, and many instances might be pointed out of its not being attended to at all.
Flagelliformis, long and pliant, like the Common Jasmine, Jasminum officinale, Curt. Mag. t. 31, or Virginian Silk, Periploca græca, Fl. Græc, t. 249.
Sarmentosus, trailing. A creeping stem, barren of flowers, thrown out from the root for the purpose of increase, is called sarmentum or flagellum, a runner, as in the Strawberry, Fragaria vesca, Engl. Bot. t. 1524. When leafy it is generally denominated stolo, a sucker or scyon, as in Bugle, Ajuga reptans, t. 489, and Viola odorata, the Sweet Violet, t. 619. When the stolo has taken root, it sometimes flowers the first year, see Curt. Lond. fasc. 1. t. 63, but generally not till the following season.
Rectus, straight, as in Lilium, the different species of garden Lily.
Strictus, expresses only a more absolute degree of straightness.
Laxus or Diffusus, loosely spreading, has a contrary meaning, as in Bunias Cakile, Sea Rocket, Engl. Bot. t. 231, and Sedum acre, Biting Stone-crop, t. 839.
Flexuosus, zigzag, forming angles alternately from right to left and from left to right, as in Smilax aspera, Ger. em. 859, and many of that genus, also Statice reticulata, Matted Sea Lavender, Engl. Bot. t. 328. In a less degree it is not unfrequent. See Atriplex pedunculata, t. 232.
Alternè ramosus, alternately branched, as Polygonum minus, t. 1043, Dianthus deltoides, t. 61, &c.
Distichus, two-ranked, when the branches spread in two horizontal directions, as in the Silver Fir, Pinus picea, Duhamel, Arb. v. 1. t. 1.
Brachiatus, brachiate, or four-ranked, when they spread in four directions, crossing each other alternately in pairs; a very common mode of growth in shrubs that have opposite leaves, as the Common Lilac, Syringa vulgaris.
Ramosissimus, much branched, is applied to a stem repeatedly subdivided into a great many branches without order, as that of an Apple or Pear-tree, or Gooseberry-bush.
Prolifer, proliferous, shooting out new branches from the summits of the former ones[1], as in the Scotch Fir, Pinus sylvestris, Lambert's Pinus, t. 1. and Lycopodium annotinum, Engl. Bot. t. 1727. This is obsolete, and seldom used.
Determinatè ramosus, abruptly branched, when each branch, after terminating in flowers, produces a number of fresh shoots in a circular order from just below the origin of those flowers. This term occurs frequently in the later publications of Linnæus, particularly the second Mantissa, but I know not that he has any where explained its meaning. It is exemplified in Azalea nudiflora, Curt. Mag. t. 180, Erica Tetralix, Engl. Bot. t. 1014, many Cape Heaths, and other shrubs of the same Natural Order.
Articulatus, jointed, as in Samphire, Salicornia annua, Engl. Bot. t. 415, and more remarkably in the Indian Figs, Cactus Tuna, &c.
In shape the Stem is
Teres, round, as in Trollius europæus, Engl. Bot. t. 28, and Hydrangea hortensis, Sm. Ic. Pict. t. 12.
Anceps, two-edged, as Sisyrinchium striatum, Sm. Ic. Pict. t. 9. S. gramineum, Curt. Mag. t. 464, and some of the genus Lathyrus.
Trigonus, or Triangularis, triangular or three-edged, as Cactus triangularis, Plukenet, t. 29. f. 3.
Triqueter, three-sided, is applied to a stem with 3 flat sides.
Tetragonus, or Quadrangularis, square, as Lamium album, White Dead-nettle, Engl. Bot. t. 768, and a multitude of other plants.
Pentagonus, or Quinquangularis, five-sided, as Asparagus horridus, Cavanilles Ic. t. 136, where however the character is not well expressed.
When the number of angles is either variable, or more than five, it is usual merely to describe the stem as angulosus, angular, except where the precise number makes a specific difference, as in the genus Cactus.
Alatus, winged, when the angles are extended into flat leafy borders, as Passiflora alata, Curt. Mag. t. 66, Lathyrus latifolius, Engl. Bot. t. 1108, and many others of the Pea kind, besides several Thistles, as Carduus acanthoides, t. 973, palustris, t. 974, and Centaurea solstitialis, t. 243.
The Surface of the Stem is
Glaber, smooth, opposed to all kinds of hairiness or pubescence, as in Petty Spurge, Euphorbia Peplus, Engl. Bot. t. 959, and numerous plants besides.
Lævis, smooth and even, opposed to all roughness and inequality whatever, as in the last example, and also Euonymus europæus, t. 362.
Nitidus, polished, smooth and shining, as Chærophyllum sylvestre, t. 752.
Viscidus, viscid, covered with a clammy juice, as Lychnis Viscaria, t. 788.
Verrucosus, warty, like Euonymus verrucosus, Jacq. Fl. Austriaca, t. 49, and Malpighia volubilis, Curt. Mag. t. 809.
Papillosus, papillose, covered with soft tubercles, as the Ice plant, Mesembryanthemum crystallinum. Dill. Elth. t. 180.
Scaber, rough to the touch from any little rigid inequalities, opposed to lævis, as Caucalis Anthriscus, Engl. Bot. t. 987, Centaurea nigra, t. 278, and Stellaria holostea, t. 511.
Hispidus, bristly, as Borage, Borago officinalis, t. 36, and Chara hispida, t. 463.
Hirtus, or Pilosus, hairy, as Salvia pratensis', t. 153, and Cerastium alpinum, t. 472.
Tomentosus, downy, as Geranium rotundifolium, t. 157, very soft to the touch.
Villosus, shaggy, as Cineraria integrifolia, t. 152.
Lanatus, woolly, as Verbascum pulverulentum, t. 487, V. Thapsus, t. 549, and Santolina maritima, t. 141.
Incanus, hoary, as Wormwood, Artemisia Absinthium, t. 1230, and Atriplex portulacoides, t. 261, in the former case from close silky hairs, in the latter from a kind of scaly mealiness.
Glaucus, clothed with fine sea-green mealiness which easily rubs off, as Chlora perfoliata, t. 60 and Pulmonaria maritima, t. 368.
Striatus, striated, marked with fine parallel lines, as Oenanthe fistulosa, t. 363.
Sulcatus, furrowed, with deeper lines, as Smyrnium Olusatrum, t. 230.
Maculatus, spotted, as Hemlock, Conium maculatum, t. 1191.
The spines and prickles of the stem will be explained hereafter.
Internally the stem is either solidus, solid, as that of Inula crithmoides, t. 68, and numerous others; or cavus, hollow, as in Cineraria palustris, t. 151, as well as Hemlock, and many umbelliferous plants besides.
Plants destitute of a stem are called acaules, stemless, as Neottia acaulis, Exot. Bot. t. 105, and Carduus acaulis, Engl. Bot. t. 161. Such plants, when they belong to a genus or family generally furnished with stems, as in these instances and Carlina acaulis, Camer. Epit. 428, are liable from occasional luxuriance to acquire some degree of stem, but seldom otherwise. Pinguicula, Engl. Bot. t. 70 and 145, is a genus invariably stemless, while Primula, t. 4, 5, 6 and 513, is much less truly so. The term acaulis however must never be too rigidly understood, for logical precision is rarely applicable to natural productions.
Caulis fasciculatus, a clustered stem, is a disease or accident, in which several branches or stems are united longitudinally into a flat broad figure, crowded with leaves or flowers at the extremity. It occurs in the Ash, several species of Daphne, Ranunculus, Antirrhinum, &c. In a kind of Pisum, called the Top-knot Pea, it is a permanent variety propagated by seed.
2. Culmus. A Straw or Culm, is the peculiar Stem of the Grasses, Rushes, and plants nearly allied to them. It bears both leaves and flowers, and its nature is more easily understood than defined. Many botanists have thought this term superfluous.
The Culm is occasionally
Enodis, without joints, as in our common Rushes, Juncus conglomeratus, Engl. Bot. t. 835, and effusus, t. 836; Articulatus, jointed, as in Agrostis alba, t. 1189, Aira canescens, t. 1190, Avena strigosa, t. 1266, and most other grasses;
Geniculatus, bent like the knee, as Alopecurus geniculatus, t. 1250.
It is either solid or hollow, round or triangular, rough or smooth, sometimes hairy or downy, scarcely woolly. I know of no instance of such a scaly culm as Linnæus has figured in his Philosophia Botanica, t. 4, f. 111, nor can I conceive what he had in view.
3. Scapus. A Stalk, springs from the Root, and bears the flowers and fruit, but not the leaves. Primula vulgaris, the Primrose, Engl. Bot. t. 4, and P. veris, the Cowslip, t. 5, are examples of it. In the former the stalk is simple and single-flowered; in the latter subdivided and many-flowered. It is either naked, as in Narcissus, Engl. Bot. t. 17, or scaly, as in Tussilago Farfara, t. 429. In others of this last genus, t. 430 and 431, the scales become leafy, and render the Scapus a proper Caulis.
The Stalk is spiral in Cyclamen, Engl. Bot. t. 548, and Valisneria spiralis, a wonderful plant, whose history will be detailed hereafter.
Linnæus believed[2] that a plant could not be increased by its Scapus, which in general is correct, but we have already recorded an exception, p. 112, in Lachenalia tricolor. The same great author has observed[3] that "a Scapus is only a species of Pedunculus." The term might therefore be spared, were it not found very commodious in constructing neat specific definitions of plants. If abolished, Pedunculus radicalis, a radical flower-stalk, should be substituted in its room.
4. Pedunculus, the Flower-stalk, springs from the stem, and bears the flowers and fruit, not the leaves. Pedicellus, a partial flower-stalk, is the ultimate subdivision of a general one, as in the Cowslip, and Saxifraga umbrosa, Engl. Bot. t. 663.
The Flower-stalk is
Caulinus, cauline, when it grows immediately out of the main stem, especially of a tree, as in Averrhoa Bilimbi, Rumph. Amboin. v. 1. t. 36, the Indian substitute for our green gooseberries.
Rameus, growing out of a main branch, as in Averrhoa Carambola, ibid. t. 35, and Eugenia malaccensis, Exot. Bot. t. 61.
Axillaris, axillary, growing either from the bosom of a leaf, that is, between it and the stem, as Anchusa sempervirens, Engl. Bot. t. 45, and Campanula Trachelium, t. 12; or between a branch and the stem, as Ruppia maritima, t. 136.
Oppositifolius, opposite to a leaf, as Geranium pyrenaicum, t. 405, G. molle, t. 778, and Sium angustifolium, t. 139.
Internodis, proceeding from the intermediate part of a branch between two leaves, as in Ehretia internodis, L' Heritier Stirp. t. 24, Solanum carolinense, Dill. Hort. Elth. t. 259, and indicum, t. 260; but this mode of insertion is rare.
Gemmaceus, growing out of a leaf-bud, as the Barberry, Berberis vulgaris, Engl. Bot. t. 49.
Terminalis, terminal, when it terminates a stem or branch, as Tulipa sylvestris, t. 63, and Centaurea Scabiosa, t. 56.
Lateralis, lateral, when situated on the side of a stem or branch, as Erica vagans, t. 3.
Solitarius, solitary, either single on a plant, as in Rubus Chamæmorus, t. 716, or only one in the same place, as in Antirrhinum spurium, t. 691, and many common plants.
Aggregati Pedunculi, clustered flower-stalks, when several grow together, as in Verbascum nigrum, t. 59.
Sparsi, scattered, dispersed irregularly over the plant or branches, as Linum perenne, t. 40, and Ranunculus sceleratus, t. 681.
Uniflori, biflori, triflori, &c. bearing one, two, three, or more flowers, of which examples are needless.
Multiflori, many-flowered, as Daphne Laureola, t. 119.
When there is no Flower-stalk, the flowers are said to be Sessiles, sessile, as in Centaurea Calcitrapa, t. 125, and the Dodders, t. 55 and 378.
The subject of inflorescence, or particular modes of flowering, will be explained in a future chapter.
5. Petiolus. The Footstalk, or Leaf-stalk. This term is applied exclusively to the stalk of a leaf, which is either simple, as in Ranunculus parviflorus, Engl. Bot. t. 120, Sium angustifolium, t. 139, and all simple leaves; or compound, as Coriandrum sativum, t. 67, and Fumaria claviculata, t. 103. In the latter the footstalks end in tendrils, and are called Petioli cirriferi.
This part is commonly channelled on the upper side. Sometimes it is greatly dilated and concave at the base, as in Angelica sylvestris, t. 1128.
The Footstalk bears the Flower-stalk in Turnera ulmifolia, Linn. Hort. Cliff. t. 10, Menyanthes indica, Curt. Mag. t. 658, and perhaps Epimedium alpinum, Engl. Bot. t. 438.
6. Frons. A Frond. In this the stem, leaf and fructification are united, or, in other words, the flowers and fruit are produced from the leaf itself, as in the Fern tribe, Scolopendrium vulgare, Engl. Bot. t. 1150, Polypodium vulgare, t. 1149, Aspidium, t. 1458—1461, Osmunda regalis, t. 209, &c. It is also applied to the Lichen tribe, and others, in which the whole plant is either a crustaceous or a leafy substance, from which the fructification immediately proceeds. Linnæus considered Palm-trees as fronds, so far correctly as that they have not the proper stem of a tree, see p. 58; but they are rather perhaps herbs whose stalks bear the fructification. It must however be observed that the deposition of wood in ferns, takes place exactly as in palms.
The term frond is now used in the class Cryptogamia only.
7. Stipes, Stipe[4], is the stem of a frond, which in ferns is commonly scaly. See the plates cited in the last section. The term is likewise applied to the stalk of a Fungus, as the Common Mushroom, Agaricus campestris, Sowerby's Fungi, t. 305.