120 THE FLORA OP THE DAKOTA GROTTP 



etc. The priiiuiry nerves, two or three, rather alternate than opposite, 

 are mostly eqiiidistaut with the secondaries and with the same angle of 

 diverg-enoe (30° to 40°), much branching outside, the few lower branches 

 only not corresponding to teeth, being camptodrome. 



The species has a degree of affinity to V. Schmkltiamim Heer\ from 

 which it differs by the leaves being cuneiform, not rounded at the base, the 

 nervation subi)almately trifid, with lateral nerves somewhat more distant. 

 The areolation and the form of the leaves are the same. 



Habitat: Ten miles northeast of Delphos, Kansas. No. 4192 of the 

 collection of Mr. K. D. Lacoe. 



Viburnum grewiopsideum, sp. nov. 

 PI. XXI, Fig. 4. 



Similar to the preceding species; a single leaf, differing by smaller size, 

 thinner texture and equilateral form. The secondaries are less distant, more 

 branched, the nervilles connivent at an angle near the borders, with branches 

 passing at right angles from the angular point of union to the borders as in 

 leaves of Grewiopsis. The teeth are shorter, less marked, separated by flat 

 sinuses. This and the preceding species are typical of T". lantanoldes and 

 V. eUipticum of our present flora. 



Habitat: Ellsworth County, Kansas. No. 834 of the museum of the 

 University of Kansas; E. P. West, collector. 



Viburnum robustum, sp. nov. 

 PI. XX, Figs. 4-6. 



Leaves coriaceous, polished on the surface, entire, oblong, oval or 

 ovate, narrowed downward, slightly decurrent at the \evy base to a long, 

 thick petiole, penninerved; median nerve thick, secondaries strong, camji- 

 todrome to brachydrome. 



These fine leaves, which are S*"™ to lO*"" long and h™ to G™ broad at 

 the middle, with a thick petiole 2.5"" to 3"'" long, have a nervation com- 

 parable to that of the leaves of Poptdus mutahilis Heer, which they also 

 resemble by their thick texture. The secondaries, diverging at an angle of 

 30° to 50° from the median nei've, fork at a distance from the l)orders, their 

 divisions anastomosing in curves forming a double row of marginal 'areoles. 

 This type of nervation is still very marked in some living species of 

 Vibmuium, as in V. nudum L., V. Lentago L., and its numerous varieties, and 



'Flora of Sacbaliu, V\. Foss. Arct., vol. h, pt. '.!, p. 43,' PI. XI, Figs. 4-8. 



