A Review of Important Literature Pertaining to Stipules

" 1. Buds are called foliar when, the leaves being sessile, the blade itself, reduced to the form of a scale, forms the buds, as in Daphne mezereum L.

" 2. They are called petiolar when the bases of the petioles dila ted into scales form the covering of the young shoot. This oc curs in petiolate leaves without stipules, as in the walnut, ash and horse-chestnnt.

" 3. Buds are stipular when the scales are formed, not by the leaves, but by the stipules which are not united with the petioles. Of these there are two sorts,—those which are formed by a great number of stipules enclosing a young shoot collectively, as in oaks, willows and elms, and those in which the stipules, free or united by their exterior margins, form a peculiar envelope for each leaf, as in Flees and the magnolias.

" 4. When the stipules are adherent with the petiole, these two organs united into one form the bud scales, and are named ful oral. This occurs in most of the Rosacere, and the scales are frequently three-lobed or three-toothed, indicating the origin of the scale formed by the petiole and the two stipules united to gether." Plate 21, figure 9, shows the progressive change from scales to foliage-leaves in buds that are fulcral in nature.

Bischoff, G.

der Botanik. 177-183. 1834.

The subject is here more fully outlined than in De Candolle's Organographie. Stipules are defined as peculiar leafy expan sions at the base of a free middle leaf. They are recognized as belonging to the leaf on the ground of their frequent connection with the petiole, the receiving of their vascular bundles from those of the leaf and the absence of buds from their axils. Va rious kinds of stipules are described and the ochrea, the ligule, the stipule in the Naiadacere and the ochrea of palms are included with stipular formations.

Lindley,

to Botany, 99. 1832.

The following statement is of interest : "The exact analogy of stipules is not well made out. I am clearly of opinion that, not withstanding the difference in their appearance, they are really accessory leaves ; because they are occasionally transformed into leaves, as in Rosa bracleala, because they are often indistinguish able from leaves of which they obviously perform all the func tions, as in Lathyrus, and because there are eases in which buds develop in their axilla, as in Salix, a property peculiar to leaves and their modifications." The character of stipules is denied to the tendril of the Cuctirbitaccre and the tendrils of Smilax (p. 96)

are regarded as lateral branches of the petiole.

Henry, A.

Recherches sur les bourgeons. Nova Acta Acad. Nat. 18 : 525 540. 1836. (Cited by Clos in Bull. Soc. Bot. Fr. 26: 193. 1879.) Henry says that he recognizes in the Betulacem and Cnpuliferre that the bud-scales are formed by stipules in an anamorphosed condition, and that in Platanus they are formed by the ochres as he terms the basal foliar appendage in this genus.

Lestiboudois, Them.

Etudes sur l'anatomie et la physiologie des vegetaux. 1840. (Cited by himself in Bull. Soc. Bot. Fr. 4 : 746-747. 1857.) The author states that he has shown that stipules are parts of the leaf, formed by the bundles or lateral fibers of these organs, whether they arise from bundles not yet having left the stem, from anastomosiug arcades which unite the leaves as in the Stellatae, or from the fibres of the petiole, as in the ftdnate stipules of Rosacem, or whether they are in part supplied by bundles directly from the cauline cylinder, as in Platanus.

In relation to the tendril in the Cucurbitaceae, be states that its bundles are derived from those which pertain to the axillary bud ; that it is therefore not a stipule, but the first foliar appendage of the axillary branch for its fibro-vascular bundles are not disposed like those of stems, but are analogous with those of petioles.

St. Hilaire, Aug.

Lecons de Botaniquc. 170, 1840. (Quoted by Colomb in Ann. Sci. Nat. (VII), 6 : 28. 1887.) It is stated that the tendrils of Smilax are to be considered as lateral leaflets of a compound leaf.

Agardlt, J.

G.—Ueher die Nebenbliitter der Pflanzen. (Reviewed by Fries and Wahlberg in Flora, 33 : 758-761. 1850.) Agardh believes that, although stipules have been considered as degenerate appendages of the leaf or modifications of it, they are not at all a part of the leaf because they are formed before it, and must be considered as independent organs. The outer bud-scales and also the protective coverings of the earliest shoots of a plant are a kind of stipule-formation, leading to the conclusion that in the lower part of a shoot or the outer part of a bud the stipule. formation preponderates, and in the upper or inner parts, the leaf formation, so that often at the lowest nodes the leaf does not de velop and at the upper stipules are absent. In Tussilago there are special leafy shoots and the flowering shoots are provided with stipules only.