Corolla

“ The corolla is shaped like an urn, with 5 spreading, rounded lobes, their edges curving or even curling in toward the center; the texture is very fine and thin, showing the veins; the large throat is downy on the inside; sometimes the margin is crinkled; the color is a pure yellow. The 4 yellow stamens are divided into a long and a short pair; the pistil is green. The calyx is 5-parted with a noticeable rounded cleft between the divisions; it is half as long as the corolla, very downy, and green. ”

“ A corolla with a single petal, unipetalous, which we must not confound with the monopetalous corolla, is a monstrosity, created by defective development; the other petals or foliola are abortive. A corolla with two petals, or dipetalous, as in Circæa Lutetiana, is rare. A tripetalous corolla occurs only when the calyx has likewise three foliola. But in this instance opinions are divided: the majority will not admit more [226] than a single floral envelope,—a perianth of six foliola, of which three, herbaceous and internal, alternate with three petaloid and external. ”

“ Besides the above purposes, I have always conceived the Corolla to fulfil some important office to the essential parts of the flower with respect to air, and especially light. It not only presents itself in a remarkable manner to the sun-beams, frequently closing or drooping when they are withdrawn, but it is so peculiarly distinguished by beauty or brilliancy of colour, that one cannot but think its functions somewhat different from those of the leaves, even with regard to light itself. ”

“ A monopetalous Corolla consists of two parts; the tube, tubus, the cylindrical part enclosed in the calyx of the Primrose; and the limb, limbus, which is the horizontal spreading portion of the same flower. The analogous parts of a polypetalous Corolla, as in the Wall-flower or Stock, are named the claw, unguis, and the border, lamina.
The Corolla is infinitely diversified in form in different genera, which Tournerfort and Rivinus derived their methods of arrangement. It is called regular when its general figure is uniform, as in the Rose, the Pink, the Columbine, Aquilegia vulgaris, Engl. ”

“ Kerner, Nature has recourse to a more complex machinery: the corolla first closes over the anthers, which are at a lower level than the stigma, and takes off some of the pollen; a growth of the corolla carries the pollen dust to the level of the stigma, and a second closing of the corolla transfers the pollen to the stigmatic surface. ”

“ Ligulate Corolla. The ligulate or Strap-shaped corolla mainly belongs to the family of Compositæ, in which numerous small flowers are gathered into a head, within an involucre that imitates a calyx. It is best exemplified in the Dandelion and in Chiccory (Fig. 266) . Each one of these straps or Ligules, looking like so many petals, is the corolla of a distinct flower: the base is a short tube, which opens out into the ligule: the five minute teeth at the end indicate the number of constituent petals. ”

“ Sometimes the Corolla is very short-lived; sometimes very lasting, even till the fruit is perfected, though mostly in a faded condition. In double flowers I have observed it to be much more durable than in single ones of the same species, as Anemones and Poppies, because, as I conceive, of its not having performed its natural functions, the stamens and pistils of such flowers being obliterated, or changed to petals; hence the vital principle of their corolla is not so soon exhausted as usual. ”

“ Corolla 5-parted (rarely 4–8-parted) , large, the lobes mostly soft-downy. Stamens twice as many as the lobes of the corolla; filaments flat, united at the base into a short tube; anthers linear, adnate. Fruit globular, its base surrounded by the persistent calyx, 1-celled, mostly 1-seeded, dry, often 3-valved. Seed globular, erect, with a hard coat.—Shrubs or small trees, with commonly deciduous leaves, and axillary or leafy-racemed white and showy flowers on drooping peduncles; produced in spring. Pubescence scurfy or stellate. ”

“ The flowers are generally borne in capitula, racemes, or spikes.—Trifolium (Clover) . The corolla is gamopetalous. The calyx persists, together with the corolla, round the ripe fruit. The inflorescence is a spike, capitulum or capitate umbel; the leaves are ternate, and have adnate stipules.—Medicago (Medick) . The corolla falls off after flowering; fruit curved like a sickle or spirally twisted; it is a nut, and opens with difficulty. Leaves ternate.—Melilotus (Melilot) has a small, spherical or lanceolate, thick and wrinkled fruit, which as a rule is indehiscent. ”

“ In the first place, a corolla with five petals of a delicate rose-hue, very pleasant to the sight.
Take care! those foliola are not petals, if you give that name to the free parts of the corolla. Look at them thoroughly. Your foliola are prolonged at their base in a narrow tube, which is easily removed. If you had begun here,—if, instead of proceeding from the top to the bottom, you had, in your analysis, proceeded from the bottom to the top, you would [252] have acquired a wholly different view of things. ”

“ The corolla shows great variety in form; thus among the British genera it is rotate in Chlora, funnel-shaped in Erythraea, and cylindrical, bell-shaped, funnel-shaped or salver-shaped in Gentiana; the segments are generally twisted to the right in the bud; the throat is often fimbriate or bears scales. The stamens, as many as, and alternating with, the corolla-segments, are inserted at very different heights on the corolla-tube ”

“ Corolla funnel-shaped, with 4 oval, pointed, spreading lobes that equal the slender tube in length; rarely the corolla has more divisions; 4 stamens inserted on tube of corolla; 2 stigmas; calyx 4-lobed. Leaves: Opposite, seated on stem, oblong, tiny; the lower ones spatulate. Fruit: A 2-lobed pod, broader than long, its upper half free from calyx; seeds deeply concave. Root-stalk: Slender, spreading, forming dense tufts. ”

“ And if even but a small effect is producible on the growth of the corolla, then it is to be expected that light will be an agent in changing the form of the corolla, when the attitude of the flower causes its parts to be differently exposed. ”

“ When the petals are equal as regards their development and size, the corolla is regular; when unequal, it is irregular. When a corolla is gamopetalous it usually happens that the lower portion forms a tube, while the upper parts are either free or partially united, so as to form a common limb, the point of union of the two portions being the throat, which often exhibits a distinct constriction or dilatation. ”

“ We are glad our morning-glory kept this little notch and the line where the sides of the petals grew together, for that is what tells us the story of long, long ago when all the petals were separate.
When finally they were grown together, the corolla did not need to be so stiff, for its shape helped to make it firm, and then it no longer used good material to make stiffening for the petals, for that would have been a waste of plant sap, and plants do not like to waste materials. When they find they can get along without something they have been used to having, they stop making it. ”

“ Deficiency of the corolla was observed in Campanula perfoliata and Ruellia clandestina by Linné, who calls such blooms flores mutilati. [480] Drs. Hooker and Thomson relate a similar occurrence in Campanula canescens and C. colorata. Some plants seem as a normal occurrence to produce flowers of different construction, and are hence termed dimorphic, as in many Malpighiaceæ, Violaceæ, Oxalidaceæ, in some of the flowers of which the petals are altogether wanting, while in others the [Pg 404] corolla is developed as usual. ”

“ In the particular flowers now alluded to the tubular form seems due to a dilatation, and not to a cohesion of the margins. (See Cohesion, p. 23.) These tubular petals resemble in form and colour almost precisely the normal corolla in miniature, but are not surrounded by a calyx, nor do they contain stamens, while the less perfect forms show clearly their origin from a single tube-like organ.
Fig. 168.—Corolla of Primula sinensis turned back to show a tubular petal springing from it. One only is shown for the sake of clearness; they are generally numerous. ”

“ The corolla is about half an inch across, wheel-shaped, with no tube 363 364 and usually with six, white or pinkish petals, sometimes deep pink, or flecked with lilac outside. The ovary makes a purplish dot in the center, surrounded by curling, yellow anthers, with threadlike filaments united at base. The capsule contains a few, rather large, white seeds. We often find these dainty little plants growing in companies, their starry blossoms glimmering in the shade, prettily set off by their neat circle of leaves. ”

“ Calyx persistent. Corolla mostly withering-persistent; the stamens inserted on its tube. Seeds anatropous, with a minute embryo in fleshy albumen. (Bitter-tonic plants.)
Suborder I. Gentianeæ. Leaves always simple and entire, sessile, never alternate. Æstivation of corolla never valvate.
[*] Lobes of corolla convolute in the bud.
[+] Style filiform, usually deciduous; anthers oblong to linear, mostly twisting or curving in age.
1. Erythræa. Parts of flower 5 or 4; corolla salver-form; anthers twisting spirally.
2. Sabbatia. Parts of flower 5–12; corolla rotate; anthers recurved or revolute. ”

“ Calyx 5-parted; the upper division broadest, the innermost often very narrow. Upper lip of the corolla entire, notched or 2-cleft, and the lower 3-lobed, or the limb nearly equally 5-lobed. Stamens 4, all fertile. Style dilated or 2-lobed at the apex. Seeds numerous.—Low herbs, with opposite leaves, and solitary axillary flowers; in summer; ours rather succulent perennials. (Name from ἑρπηστής, a creeping thing, the species being chiefly procumbent.)
[*] Corolla plainly bilabiate, the 2 upper lobes united to form the upper lip; leaves many-nerved. ”

“ A large family, widely distributed, chiefly rough-hairy herbs, without stipules; usually with alternate, toothless leaves; flowers usually in coiled, one-sided clusters; calyx usually with five sepals; corolla usually symmetrical, with five united petals, often with crests or appendages in the throat; stamens five, inserted in the tube of the corolla, alternate with its lobes; ovary superior, with a single, sometimes two-cleft, style, and usually deeply four-lobed, like that of the Mint Family, forming in fruit four seed-like nutlets. ”

“ The flowers of the dandelion are all of one type. The corolla is strap-shaped (Fig. 86, 2) , and of a beautiful yellow colour to attract insects. On the end of the strap may be seen five small teeth which indicate that it really consists of five [Pg 114] united petals. At the base of the corolla is a tuft of fine hairs, which is the top of the calyx-tube, and at the bottom of the flower is a little white knob—the ovary. The five stamens are fixed on the inside of the corolla-tube. Their anthers are united to form a tube through which the upper part of the style, and the forked stigma protrude. ”

“ The corolla is salver-shaped, with a long tube, and a spreading, five-parted limb. The anthers are nearly sessile, and the short filaments to which they are at88 tached are inserted in the throat of the corolla, only the tips of the anthers being visible. The stigma is divided into two fleshy lobes, and the capsule splits, not like that of Cinchona, but from the apex to the base in the centre of each cell. The seeds are very small, and each has a toothed, membranous wing. The flowers of this beautiful plant are produced in a large head, and at first sight greatly resemble those of a Hydrangea ”

“ Calyx 5-parted. Corolla rotate, with no proper tube, deeply 5-parted, the sinuses rounded; divisions ovate, cuspidate-pointed, erose-denticulate above, each separately involute around its stamen. Filaments distinct or nearly so on the ring at base of corolla, alternating with 5 subulate staminodia; anthers linear. Capsule 10–20-seeded.—Leafy-stemmed perennials, glabrous except the ciliate petioles, not punctate, the leaves all opposite, but mostly in seeming whorls on the flowering branches. Peduncles slender, axillary, bearing yellow flowers. ”

“ A monopetalous corolla not splitting at the base is necessarily connected with this structure, which seems also peculiarly well adapted to the dense inflorescence of Compositæ; the vessels of the corolla and stamina being united and so disposed as to be least liable to suffer by pressure. ”

“ The relationship of the corolla to the leaves of the stalk is shown in more than one way, since on the stalks of some plants appear leaves which are already more or less colored long before they approach inflorescence; others are fully colored when near inflorescence. Nature also goes over at once to the corolla, sometimes by skipping over the organs of the calyx, and in such a case we likewise have an opportunity to observe that leaves of the stalk become transformed into petals. ”

“ Imperfect development of the whole or of some of the constituent parts is more common in the case of the corolla than in that of the calyx. In Arenaria serpyllifolia the petals, especially in autumn, are only one fourth the length of the sepals. Anagallis phœnicea, Honckenya peploides, Arabis alpina, Ranunculus auricomus, Rubus fruticosus, and Geranium columbinum, also frequently afford illustrations of this circumstance. ”