Venation
Collier's New Encyclopedia (1921)
the arrangement of the veins in the leaves of plants. If a leaf has only a single midrib without branches as in many Coniferæ, the venation is said to be simple. The three leading types of venation are the reticulated, netted, or angular, found in the exogens and a few aberrant endogens; the parallel, or curved, found in all the higher endogens; and the furcate, or forked, characteristic of ferns. Lindley 101 made 10 divisions: veinless, equal-veined, straight-veined, curve-veined, netted, ribbed, falsely ribbed, radiating, featherveined, and hidden-veined. Professors McCosh and Dickie considered that they had traced a connection between the ramifications of plants and their venation. VENDÉE (vong-dā'), LA, a maritime department of western France; bounded on the W. by the Bay of Biscay, on the N. by Loire-Inférieure, and on the S. by Charente-Inférieure; area, 2,690 VENDÉE, LA, WAR OF The square miles; pop. about 450,000. department, which owes its name to a small affluent of the Charente, is traversed from E. to W. by a range of hills, called in the E. the Plateau de Gatin, and in the W. the Collines Nantaises, and is watered in the N. by the affluents of the Loire, and in the S. by the Lay and the affluents of the Charente. Of its three divisions the W. is the Marais, occupied by salt marshes and lakes; the N. the Bocage, covered with plantations; in the S. and middle is the Plaine, an open and fertile tract. The coast line, 93 miles in length, presents few deep indentations, the chief being the safe Bay of Aiguillon. VENDÉE, LA, WAR OF, the Royalist resistance to the French Revolution, which occurred chiefly in Vendée and Brittany. It broke out in Vendée, in March, 1793; gained a victory at Saumur, in June, 1793; but under La Rochejacjuelin was decisively defeated by the Republican forces under Westermann and Marceau at Le Mans, Dec. 12, 1793. The struggle still went on in Brittany, under the name of the War of the Chouans; but was suppressed by General Hoche in 1796; and finally by Napoleon Bonaparte in 1800. The principal Vendean leaders were La Rochejacquelin, Cathelineau, Charette, and Stofflet. VENDÉMIAIRE (vong-da-myār'), the first month in the French Republican calendar, beginning Sept. 22 or 23, and ending Oct. 21 or 22; so called from its being the vintage season.
What Has Changed in the Last Century
Collier's in 1921 still sorted leaves by Lindley's mid-19th-century scheme, dividing them between "exogens" and "endogens" and listing ten vein classes; those group names are gone, replaced by monocots and (since molecular phylogenies of the 1990s) eudicots, and the parallel venation of monocots is now read as a derived condition rather than a badge of rank. The descriptive vocabulary survives — reticulate, parallel, dichotomous (the old "furcate") venation in ferns are all still taught — and a standardised terminology for leaf architecture was set out for palaeobotanists in the 1970s and 1990s, letting fossil leaves be identified from vein pattern alone. What is wholly new is the functional account: veins are studied as a plumbing and supply network, and measurements of vein density show a sharp rise in flowering plants during the Cretaceous, tied to higher rates of water transport and photosynthesis. The natural-theology instinct of McCosh and Dickie, who sought a designed correspondence between a plant's branching and its venation, has given way to explanations from hydraulics and development.
Written for this edition, 2026.