R. H. Howe: MANUAL OF THE GENUS USNEA ed 
4. Fruiting branch of Usnea florida (L.) Web. (slightly reduced) showing normal 
development 
5. Microscopic photograph of cross-section of thallus of Usnea florid, showing 
axis cord, medulla, algal cells, and cortex with papillae. 
PLATE 3 
Usnea plicata (L.) Web, (4 nat. size), Represents the highest development 
found in eastern North America. Collected in Plymouth, N. H,, March, 1go1, and 
kindly loaned for reproduction by Dr. L. W, Riddle from the Herbarium of Wellesley 
College. 
2. Specimen ae St. Martinsville, La,, kindly loaned by Professor Bruce Fink. 
oe phase 
nea pice (L. ) Web. = [ Usnea vulgaris]. Dillenius’ figure, Hist. Muse. 
pl ITs oe 
4. Seats ae (L.) Web. ey ae a portion of a plant (4 nat. size) show- 
ils the highest development attained {— U. californica Herre). Specimen collected 
by M. A. Howe, April 5, 1893, Coast iets Marin Co., Cal. Vo. 7763, author’s 
Sevan kindly given by Dr, L. W. Riddle. 
PLATE 4 
1. Usnea plicata barbata (L.) R. H. paeea mos barbata]. Dillenius’ 
aie Hist. Muse. p/. r2. f. 6. 1741. Reduced to abou 
Usnea trichodea Ach. Specimen vo. i author’s co collected Jan. 7, 
on Fitzwilliam, N. H., reduced to 3 nat. siz 
R. 
snea plicata barbata (L.) H. Howe Typical specimen representing 
normal development in or jaarrines North America (,%; nat. size). Specimen from 
Westbrook, Me., collected Aug 1908, In the herbarium of the Portland Society 
of Natural History, kindly Sheiats a Mr. A. H. Norton. 
4. Usnea trichodea Ach. Acharius’ original figure, Meth. Lich. 1803. Reduced 
nearly one ha 
PLATE 5 
1. Usnea articulata (L.) Hoffm. =[Usnea capillacea & nodosa]. Dillenius’ 
cot Hist. Muse. p/. zz. fi g. 1741. 
Usnea articulata (L.) Hofim. Specimen in the U. S. National a 
ilies from the British Isles. Kindly loaned by Assoc. Curator J. N. Rose. 
3. Usnea cavernosa Tuck, Specimen mo. +7g8, author’s herbarium, erat Bruns- 
wick, Me., Jan., 1909. Kindly sent by Dr. Manton Copelan 
4. Microscopic photograph of cross-section of thallus of vee cavernosa, showing 
axis oe medulla, algal cells, and foveola. 
PLATE 6 
Usnea longissima Ach. Acharius’ figure, Nova Act. Soc. Sci. Upsal. 7: f/. 7- 
jf. 5. 1815. Reduced. 
PLATE 7 
1. Usnea angulata Ach., representing the highest development. Specimen from 
eastern Bolivia, Apolo, collected July 18, 1902, above a — Mr. R. S, Williams, 
New York Botanical Garden, and kindly loaned for reprod 
2. Specimen of Usnea angulata from Granville, Nae porcine by Miss Mary 
