Polygonum

“ Polygonum amphibium is peculiarly interesting, because, as Kerner has pointed out, aquatic specimens are glabrous; while in those living on land the base of the leaf produces hairs. Half a dozen are early spring plants which flower before the ants are roused from their winter sleep; about the same number are minute ground-plants to which hairs could be no protection ”

“ The wheels of the drays sank up to their axle-trees, and the horses above their fetlocks at every step. The fields of polygonum spread on every side of us like a dark sea, and the only green object within range of our vision was the river line of trees. In several instances, the force of both teams was put to one dray, to extricate it from the bed into which it had sunk, and the labour was considerably increased from the nature of the weather. ”

“ This family is divided into seven genera and many of these are further divided. They are all inconspicuous in flower. The genus Rumex, to which our common Sorrels belong, contain seventeen species: that of Polygonum, which contains the Knot-weeds, has 32 species included in its six sub-genera. ”

“ Polygonum Rheoides becomes abundant towards a height of 5,200 feet, when Pyrus, an apple-like species, and Spiræas make their appearance at 5,300 feet. On the Kala Panee, Bucklandia re-appears, but thence would seem to cease: on the brow of the ascent from this, Pedicularis appears in abundance among grasses, with it Sphacele? At the same height, which cannot be less than 5,400 feet, Carduus or Cnicus, appears. Solidago commences in the valley of the Kala Panee, but becomes more abundant at higher elevations. ”

“ The Polygonum Viviparum, viviparous bistort, rises about a foot high, with a beautiful spike of flowers, which are succeeded by buds or bulbs, which fall off and take root. There is a bulb, frequently seen on birch-trees, like a bird's nest, which seems to be a similar attempt of nature, to produce another tree; which falling off might take root in spongy ground.
There is an instance of this double mode of production in the animal kingdom, which is equally extraordinary: the same species of Aphis is viviparous in summer, and oviparous in autumn. ”

“ The natives puddle the bottoms and sides of these wells to prevent absorption, and as their positions are usually of a low-lying character, there is in most cases an abundant growth of polygonum, which, in a considerable measure, lessens the evaporation which the summer sun would induce. ”

“ Polygonum erectum L. Achenes dull, light to dark brown, unequally 3-sided, ovoid or rhombic, finely granular and striate lengthwise, the faces sometimes concave, the angles rounded, 2.5–3 mm. long, sometimes with the remains of calyx attached. Native to this country. Of little account.
Fig 34. Smart-weed. Polygonum Hydropiper L.
Smart-weed. ”

“ Elæagnus, Mespilus microphyllus, Polygonum of Chugur; 2 or 3 Amaranthaceæ; Prinsepia, rare; very little variety in ferns; Pteris chrysocarpa, Aspidium pungens, and another are the most common; nor is there any variety in Epiphytous ferns, and very few Jungermannias. The Mosses are Bartramia, Catharinea, Polytrichum aloides on banks with Fissidens, otherwise Hypna are the most prevalent. A Neckera hangs from every tree, and a Pterogonio Neckeroid covers almost every trunk, a Brachymenium is likewise common. ”

“ The temperature of this is said to be hot in winter. Salsola common, Joussa, a curious Ericoid plant was observed, Typha angustifolia, latifolia ceased since we left Gundamuck; Isachne, Pulicaria, Epilobium, Sagittaria, Cyperaceæ, Marsilea! Polygonum, Ranunculus sceleratus, Lythrum, Lemna, Alisma, Menthoid, a Cuscuta common on cotton plants, as at Futtehabad, several tropical grasses, Aristida, Poa, and Andropogon appear.
Descent though almost unappreciable, yet amounts to 1,000 feet. Bulbul and Parus common, as well as doves and ravens; quails are scarce. ”

“ The Polyzoa are chiefly marine, and the common "sea-mat," often erroneously treated as a sea-weed, is a well-known form. A species of another order often picked up on our coasts is the Sertularia, or Sea-Fir, composed of delicate branching stems of a horny-looking substance, which, under a pocket-lens, is found to contain an immense number of small cells inhabited by Polyps. It is instructive to compare the two and note how much more advanced in structure is the Polyzoon than the polyp. ”

“ Some few even among coral-polyps live individual lives, but the greater number follow the community-system. This must always be looked upon as an inferior way of existence.
The most usual way in which polyps increase is by “budding”—not unlike the growth of a plant by buds. A small lump appears on one side of the parent, which increases fast in size, develops a mouth and tentacles, and by-and-by gives birth itself to other buds. The increase of numbers is enormous. One polyp may produce in a short time thousands or even tens of thousands of descendants. ”

“ In Gonionemus the actinula becomes fixed and polyp-like, and reproduces by budding, so that here also an alternation of generations may occur. In the Leptolinae we must first substitute polyp for actinula, and then a condition is found which can be compared to the case of Cunina parasitica or Gonionemus, if we suppose that neither the parent-actinula (i.e. founder-polyp) nor its offspring by budding (polyps of the colony) have the power of becoming medusae, but only of producing medusae by budding. ”

“ The polyp may be solitary, but more usually produces polyps by budding and forms a polyp-colony. The polyp usually has the body distinctly divisible into hydranth, hydrocaulus and hydrorhiza, and is usually clothed in a perisarc. The medusae may be set free or may remain attached to the polyp-colony and degenerate into a gonophore. When fully developed the medusa is characterized by the sense organs being composed entirely of ectoderm, developed independently of the tentacles, and innervated from the sub-umbral nerve-ring. ”

“ Gonostyles, appendages which produce by budding medusae or gonophores, like the blastostyles of a hydroid colony. In their most primitive form they are seen in Velella as “gonosiphons,” which possess mouths like the ordinary sterile siphons and bud free medusae. In other forms they have no mouths. They may be branched, so-called “gonodendra,” and amongst them may occur special forms of palpons, “gonopalpons.” The gonostyles have been compared to the blastostyles of a hydroid colony, or to the manubrium of a medusa which produces free or sessile medusa-buds. ”

“ As a rule, the polyps are either male or female; but in stock-forming species individuals of the two sexes are often mixed. Monoxenia may be taken as the simplest type of the regularly radiate polyps; in all the different organs being repeated in regular rings round a central axis; the mouth also is circular. From this interesting account, drawn by Haeckel, of a simple polyp, it will be at once seen what kind of radiate animal it is that builds up the coral reefs. “No garden on earth can match the gardens of the sea that circle the northern part of Australia. ”

“ The Hertwigs when they discovered the endoderm-lamella showed on morphological grounds that polyp and medusa are independent types, each produced by modification in different directions of a more primitive type represented in development by the actinula-stage. If a polyp, such as Hydra, be regarded simply as a sessile actinula, we must certainly consider the polyp to be the older type, and it may be pointed out that in the Anthozoa only polyp-individuals occur. ”

“ Thus the typical hydroid colony starts from a “founder” polyp, which in the vast majority of cases is fixed, but which may be floating, as in Nemopsis, Pelagohydra, &c. The founder-polyp usually produces by budding polyp-individuals, and these in their turn produce other buds. The polyps are all non-sexual individuals whose function is purely nutritive. After a time the polyps, or certain of them, produce by budding medusa-individuals, which sooner or later develop sexual elements ”

“ In the Calyptoblastea, where the polyps are protected by special capsules of the perisarc, the gonothecae enclosing the blastostyles differ from the hydrothecae protecting the hydranths (fig. 54) .
In other colonies the two functions of the nutritive polyp, namely, capture and digestion of food, may be shared between different polyps (fig. 10) . One class of polyps, the dactylozoids (dz) , lose their mouth and stomach, and become elongated and tentacle-like, showing great activity of movement. ”

“ Pycnogonomorpha, Pocock (nov.) .—Derivative forms in which the reduction in number of the anterior appendages is carried farther than in the other orders, reaching its extreme in the Pycnogonidae, where the 1st and 2nd pairs are absent in both sexes, and the 3rd pair also are absent in the female. In the Hannoniidae, however, which resemble the Pycnogonidae in the absence of the 3rd pair in the female and of the 2nd pair in both sexes, the 1st pair are retained in both sexes.
Two families: 1. Hannoniidae (genus Hannonia) ; 2. Pycnogonidae (genera Pycnogonum and Phoxichilus) . ”

“ Each petal carries on its edges a row of very slender transparent filaments, arranged like the teeth of a comb, which also arch downward, and greatly augment the beauty of the flower-like polyp.
Structurally, this polyp is closely allied to the common forms of the Sea Anemones; the most obvious peculiarity being, that a multitude are combined into one mass, with a common life animating the whole. [Pg 75] The fleshy mass is of a spongy texture, full of branching water-canals, and containing a multitude of calcareous spicula of characteristic forms. ”

“ Hence, in a colony of calyptoblastic hydroids, the oldest polyp of a system is the lowest; the youngest polyp is the topmost 140 one; and the axis of the system is a false axis composed of portions of each of the consecutive polyps. In this method of budding there are two types. In one, the biserial type (fig. 15) , the polyps produce buds right and left alternately, so that the hydranths are arranged in a zigzag fashion, forming a “scorpioid cyme,” as in Obelia and Sertularia. ”

“ Gonosome with free medusae or gonophores; medusae usually with ocelli, never with otocysts. The gymnoblastic polyp usually has a distinct perisarc investing the hydrorhiza and the hydrocaulus, sometimes also the hydranth as far as the bases of the tentacles (Bimeria) ; but in such cases the perisarc forms a closely-fitting investment or cuticule on the hydranth, never a hydrotheca standing off from it, as in the next sub-order. The polyps may be solitary, or form colonies, which may be of the spreading or encrusting type, or arborescent, and then always of monopodial growth and budding. ”

“ The skeleton of Plagonium exhibits therefore the same remarkable form which is found in the isolated spicula of numerous Beloidea (e.g., Lampoxanthium punctatum, Sphærozoum punctatum) , and bears the same relation to Hexaplagia that Plagonidium does to Tetraplagia.
1. Plagonium sphærozoum, n. sp. (Pl. 91, fig. 6) .
Spines straight and stout, three-sided prismatic, about twice as long as the common middle rod, irregularly branched or nearly verticillate, with short thorny branches. Similar to the single spicula of some species of Sphærozoum and Lampoxanthium. ”

“ 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 Polyplagia alone represents the small subfamily of Polyplagida, distinguished from the other Plagonida by the multiplication of the radial spines, the number of which amounts to seven to nine or more. This increased number is commonly the result of an intercalation of new spines between the three or four primary spines; it is sometimes also effected by stronger development of branches of the latter, which become independent. The following five species of this genus are very different, require further investigation, and perhaps represent different genera:—
1. ”

“ The polyp (hydropolyp) is of simple structure, typically much longer than broad, without ectodermal oesophagus or mesenteries, such as are seen in the anthopolyp (see article Anthozoa) ; the mouth is usually raised above the peristome on a short conical elevation or hypostome; the ectoderm is without cilia. (2) With very few exceptions, the polyp is not the only type of individual that occurs, but alternates in the life-cycle of a given species, with a distinct type, the medusa (q.v.) ”

“ The buds may all become detached after a time and give rise to separate and independent individuals, as in the common Hydra, in which only polyp-individuals are produced and sexual elements are developed upon the polyps themselves; or, on the other hand, the polyp-individuals produced by budding may remain permanently in connexion with the parent polyp, in which case sexual elements are never developed on polyp-individuals but only on medusa-individuals, and a true colony is formed. ”

“ The characteristic skeletal structure of the different species appears at a later stage. Whether ripe central capsules can emerge from the social bond of a cœnobium, and, having become isolated, establish the formation of a new colony, is very doubtful. The various forms which the cœnobium assumes in the different species of Polycyttaria, are due partly to simple growth, partly to the development of large vacuoles in the calymma. ”

“ Like the anemone they also have lasso-cells for capturing their food.
Should it be a branching coral whose history we are tracing, it will now begin to bud from the sides. The buds will grow into branches, throwing out other buds, somewhat as plants do, until we have an elegantly branching colony. Each bud is a new polyp, and remains attached to [Pg 724] the branch from which it sprang. Although the polyps in such a community have separate mouths and stomachs, there is a close connection between them, and a free circulation of fluids through the soft flesh. ”