IOWA ACADEMY OF SCIENCE 
99 
THE FLORA OF IOWA ROCK. 
A SMALL ROCKY ISLAND IN PUGET ^OUND. 
During the summer of 1908, in connection with work at the Marine Biological 
Liboratory, located at Friday Harbor, Washington, two visits were made to an 
interesting little island lying several miles to the south of the Station. The 
position of this island gave special interest to its algal flora; and, its borders, 
with adjacent shore lines, constituted one of the richest collecting grounds 
of the region. The name “Iowa Rock” was proposed for this island, and local 
revenue officers have taken steps to make this name official on the government 
maps of that region. 
Our little island, — one of the tiny ones of that wonderful archipelago of 
Puget Sound, — is a solid mass of rock rising from the waters of San Juan 
Channel. It stands ne’ar the most western extremety of Lopez island, and at a 
point opposite the southern end of San Juan island. The longer dimension of 
the rock extends in a northwest and southeasterly direction, parallel to, and 
directly bordering upon the Strait of Juan de Fuca. The outward face of the 
rock is, as a result, exposed to the full force of the winds and waves of the 
broad Sound which near at hand merges with the waters of the Paciflc ocean. 
Iowa Rock is about 100 yards long with an average breadth of perhaps fifty 
yards. The apex of the rock is fully fifty feet above the water line. Separ- 
ating it from the main-land of Lopez is a channel nearly one hundred yards 
wide through which the tidal currents sweep with great force. The rock is a 
highly metamorphosed limestone, dipping toward the Strait. The declination 
in this direction accounts in a general way for the topography of the island 
and also explains, no doubt, its escape from complete destruction by the waves. 
The seaward face of the island is steep and rugged, broken into multitudes 
of points and depressions through the numerous fractures. The shoreward 
side of the rock slopes more gently, and is quite irregular in outline. Near the 
top of the rock a considerable quantity of soil has accumulated, to the leeward 
of the crest. Elsewhere the rock was quite bare. 
The conspicuous plants found growing upon the island and along its shores 
were listed, and are given below. On the landward side of the rock, sheltered 
from the full force of the Strait winds by the rocky back bone of the island a 
number of seed plants have gained a foothold. Most of these, however, lead a 
precarious life. The few normally aborescent forms are dwarfed to mere 
btishes. The oak, Querus garryana, Dough, which, in more favored habitats 
becomes a stately tree, is here sprawling and but a few feet in height. ‘Most 
of the herbaceous forms, as might be anticipated are strongly xerophytic. The 
outward faces of the rock were barren of seed plants, due in part to scarcity 
of soil, but primarily to the severety of the winds. The land flora is therefore 
restricted almost exclusively to the sheltered hollows of the island on the side 
away from the open sea. 
