1/2 Rhodora [August 



within recent years that they have been clearly distinguished. Both 

 species produce an abundance of gemmae but are exceedingly rare 

 in fruit. The characters which separate them are derived from the 

 leaf-cells and the gemmae. In S. exsedaeformis the median cells 

 average 22 x 36 /x, and their thin walls show distinct trigones; in 

 6". exsectus the cells in the same position average 9 x 18 /x. and 

 their walls are more uniformly thickened, the trigones being incon- 

 spicuous. The gemmae of 6". exsedaeformis are angular, while those 

 of the other species are ellipsoidal or ovoid. Both species are widely 

 distributed in Europe, and an interesting account of them may be 

 found in a recent paper by M. G. Dismier, of Saint-Maur, France.^ 

 Under his Scapania exsecta, Austin quotes as a synonym the Jnnger- 

 mannia sdtula of Taylor ; the type-specimen of this species, however, 

 shows that it is abundantly distinct. Stephani also recognizes its 

 validity and describes it as Sphenolobus sdtulus (Tayl.) Steph. 



7. Sphenolobus Hellerianus (Nees) Steph. Bull, de I'Herb. 

 Boissier II. 2 : 166. 1902. Jungermaimia Helleriana^^^'&\ Linden- 

 berg, Nova Acta Acad. Caes. Leop.-Carol. 14, suppl. : 64. 1829. 

 Diplophylhim Hellerianum Dumort. Recueil d'Obs. sur les Jung. 16. 

 1835. jHtiger77iannia verruculosa Lindb. Not. pro F. et Fl. Fenn. 

 13: 369. 1874. Diplophyllda Heller iana Trevis. Mem. R. 1st. 

 Lomb. III. 4 : 420. 1877. /. verrtuulosa^ var. Helleri Lindb. Muse. 

 Scand. 8. 1879. Cephalozia Helleri Lindb. Medd. Soc. F. et Fl. 

 Fenn. 14: 65. 1887. S. Hellerianus is quoted in Gray's Manual 

 from " N. Eng. " but was omitted from the Preliminary List because 

 the record was so indefinite. There is, however, in the herbarium 

 of the New York Botanical Garden, a specimen from the White 

 Mountains, New Hampshire, collected by Oakes, and on the basis of 

 this, the species may be restored. The plant grows on rotten logs, 

 and is usually accompanied by other minute hepatics. Although 

 widely distributed in North America, it is apparently very rare. All 

 of the specimens seen have been provided with gemmae but destitute 

 of floral organs, yet this fact offers no difficulty in their determination 

 because the gemmiparous branches are so striking ; they consist of 

 short upright shoots with closely appressed and more or less imbri- 

 cated leaves, which give off the gemmae from their margins. These 

 leaves are imperfectly developed and differ considerably from the 



1 Bull. Soc. Bot. de France, 49: 204-209. 1902. 



