Iva frutescens subsp. oraria (Bartlett) R.C.Jacks.

Examined fo"
i.-pfîTrl AM EBI CAN fLORA.
[Reprinted, without change in paging, from Rhodora, Journal of the New England
Botanical Cltjbv Vol. 8 (1900).— A monthly magazine, devoted to the flora of the north-
eastern United States. Published in Boston (740 Exchange Building) and Providence
(Preston and Bounds Co.). Price 11.00 per year; to foreign countries, $1.25.]
The northern and sout&em forms of the plant known as Iva fru-
tescens differ so widely in several points that it seems best to treat
them as distinct species. The northern plant, as it occurs in Massa?
chusetts, is a shrubby perennial from two to four feet tall; generally
found on the muddy banks of tidal streams and along salt-marsh
ditches. Each clump consists of from tën to a hundred or more stems
from a single woody base. The individual stems are simple below
the paniculate inflorescence except in very old plants, where, branches
may occur several nodes below the inflorescence. Iva frutescens as
described by Small in the “Flora of the Southeastern United States”
is from 1 to 3.5 meters (3^11.5 ft.) tall. No accessible spécimens
show the base of this large southern form, but as nearly as can be
judged frôm herbarium material it has freely branched stems. This
is probably due to the fact that in the south the small branches are
not deciduous at the end of the growing season, but continue their
growth from year to year.	•
The most noticeable difference between the two plants lies in the
leaves, which are much larger and broader in the northern plant than
in the southern. The stem leaves of all available specimens of both
species were measured and the results expressed as ratio of length
to breadth. The ratio varied from to (average in the
case of the northern plant, from £ to % (average £) in the case of the
southern plant. That is, the leaves of the northern plant are relatively
twice as broad as those of the southern. Other significant differences
lie in the heads and achenes. The head of the southern plant is about
4 mm. in diameter at maturity, whereas the head of the northern
NEW YORK BOTANICAL GARDEN
HERBARIUM OF OR. H. E. HASSE
PURCHASED. 1896
NEW YORK BOTANICAL GARDEN
02926401
THE SALT-MARSH IVA OF NEW ENGLAND.
Hablet Harris Bartlett.
Iva frutescens	OAaäjuo^
Det: R. C Jackson	1957
toKtm.-imi f<r
N0ETH AMERICAN FLOW
02926401