A Review of Important Literature Pertaining to Stipules

Clog, D.—Les Vrilles des Smilax ni Folioles ni Stipules. Bull. Sue. Bot. Fr. 4: 984-987. 1857.

A summary is given of the literature pertaining to the tendrils of Smilax. They arc considered as representing two lateral leaf lets of a compound leaf by von Mohl (Veber den Ban and das Winden der Ranken and Schlingpflanzen, 41, 1827), Lindley (Introd. to Botany, Ed. 2, 118, 1835), Link (Elem. Phil. Bot. Ed. 2, 1 : 478, 1837), St. Hilaire (Lecons de Bot. 170 and 854, 1840), Le Maout (Atlas de Bot. 23, 1846) and Dnehartre (Art. vrille in Diet. Univ. Hist. Nat.).

Mirbel (tem. de Physic!. et de Bot., 2: 680, 1815), Trevi !lulus (Physiol. der Gewaehse. 2: 138, 1838), Seringe (E16in. de Bot. 175, 1841), De Candolle (Theorie Element. Ed. 3, 321, 1844), Treen1 (Ann. Sci. Nat. (III), 20: 295, 1854) and Lestiboudois (Bull. Soc. Bot. Fr. 4: 745, 1857), believe these organs to be stip ular tendrils. It is the opinion of Clos that they are neither leaf lets nor stipules, but a double lateral prolongation of the cellulo vascular elements of the petiole.

Rossman, J.

Beitriige zux Kentniss der Phyllomorpbose. 1857. (Cited by Closin Bull. Soc. Bot. Fr. 26: 192. 1879.) Rossman considers the problem of the nature of stipules, and from a study of bud-scales arrived at his conclusions. He figures the passage from bud-scales to leaves in Ribes sanguineum Pursh, Prunus Pados L., SpirEca sorbifolia L., etc. He notes the pres ence in the of three median veins, separated at the base and joining one another at the apex, where the petiole will origi nate. The lateral parts of the scale outside of these three nerves he believes to represent the stipules which show themselves at the appearance of the blade in two little points at the apex.

Hanstein,

J.—UebergfirtleformigeGefiissstmng-Verbindung in Stenglc knoten dicotyler Gewiiehse. Abltandl. der Akademie der Wissenschaften zu Ber lin, 1857 : 77-98. 1858.

The vascular nodal girdle of the Stellate is treated of at length. It is shown that from this girdle arise the bundles that supply those leaves of the whorl which are really stipules, and in some eases also the veins of the lateral parts of the true leaves. Similar

nodal girdles are shown to exist in other families of plants, nota bly in Sambucus, Valeriana, Verbena, Dipsacus, Scabiosa, Dahlia and Silphium. In SambucusE bolus L. the girdle sends oir vascular branches to true stipules. In the majority of other cases if branches arise they enter the margins of the petioles or the inter foliar portions of connate leaves. In Platanus and Liriodendron with alternate leaves, each of which receives seven vascular bun dles, a similar girdle is shown to pass around the stem posterior to the leaf, and is there joined by another small leaf-trace bundle. From this girdle arise a part of the stipular veins, the others being branches of the sixth and seventh leaf-trace bundles.

Clos, D.—S6pales Stipulaires. Bull. Soc. Bot. Fr. 6: 580-589. 1859.

It is argued from the similarity of the sepals to the divisions of the involucre (stipulium) and also to the stipules of the fully developed foliage leaves which is frequently observed, that they represent stipules. This is held to be true in many Geraniacere, Malvacere, Begoniacete and Cistacepa. In concluding Clos adds the theoretical consideration that " whether or not stipules are admitted to be organs different from the leaf, analogy seems to demand that in some cases at least they should participate in some degree in floral formation." Cosson, sur la Stipule et la Pr6feuille dans le Genre Potamo geton. Bill. Soc. Bot. Fr. 7: 715-720. 1860.

"The stipule in Potamogelon is very closely like the first leaf of one of the branches. It is homologous with the ligule of the Graminete and Cyperaceoe and is constituted by a single organ, not by two united by their margins." Eichler, A. Entwicklungsgeschichte des Mates. 22-31, 1861 (Cited by Martin Franke in Bot. Zeit. 54 ;45, 1896.) Stipules are said to arise without exception as a product of the leaf base of the primordial leaf. This mode of origin of the stipules is their chief characteristic. Their form, their more or less foliaceous condition and their persistence are secondary.