McATEE: VIBURNUM AND THE CAPRIFOLIACEAE 151 
tum frequently, one might almost say usually, has the leaves in 
whorls (three’s, sometimes four’s). The structure of plants with 
opposite leaves readily lends itself to the production of verticils, 
and as instanced here, the two types of foliation are hardly distinct 
enough to be given much weight in the major phases of classi- 
fication. 
Stipules in the Caprifoliaceae——The most persistent efforts to 
name characters that will distinguish the Caprifoliaceae from the 
Rubiaceae have been centered on stipules. It being untrue that 
the assemblage of plants known as Caprifoliaceae entirely lacks 
stipules, various niceties of language have been used to indicate a 
difference where practically none exists. ‘‘ Usually exstipulate,”’ 
lacking ‘‘true stipules,” and stipules if present adnate to the pet- 
iole are some of the expressions used. The first statement is 
more or less true but, demanding qualification, fails as a satisfac- 
tory character for distinguishing families. With respect to the 
second it must be said that special students of stipules agree in 
attributing such organs to the Caprifoliaceae.* Relative to the 
third definition, I may say that I have before me (gathered 
Maywood, Virginia, today, July 4, 1920) a piece of Sambucus 
canadensis with well-developed stipules on the petioles of leaves 
just beneath inflorescence, one of which when its leaf was stripped 
off remained adnate to the stem. In a specimen of Viburnum Op- 
ulus collected in the grounds of the United States Department 
of Agriculture, May 25, 1920, the stipules} are connected by wings 
which form a stipular cup completely encircling thestem (see 
Fic.1). In some Rubiaceae the interpetiolar stipules are reduced 
to a mere stipular line and stipular lines are present in various 
caprifoils, notably Sambucus; moreover, what essential difference 
is there between the shallow cups formed by the interpetiolar 
stipules in some Rubiaceae and the perfoliate leaves of Triosteum 
and Lonicera? The idea that true stipules can be distinguished 
* See an excellent paper on The Nature and Origin of Stipules Ae review of 
the literature), by A. A. Tyler, Ann. N. Y. Acad. Sci. 10: 1-49. pl. 1-3. April} 1897. 
These stipules are unusually large, and bear glands on their ball; thus sug- 
ea 
Similar stipules were collected on the same species in the Washington Monument 
: —. D..C., May 36, 1910, their likeness to leaves being greater, since they 
tendency to lobing. : 
