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Observations by Gary Fewless for Green Bay WI (Lat.N 44.51° Long. W 88.02° ), except as noted. For flowers lacking conspicuous petals or sepals I define "anthesis" as release of pollen by mature anthers.

May 2004

May 31

Green Bay received 8.31 inches of rain in May, 5.56 inches above the average May rainfall for the last 30 years. We had at least a trace of precipitation on 23 of the 31 days this month. Many local streams are flooded and many farm fields are also flooded. The temperature was about 2.8 °F below average for the month.

Our three commonest species of clover are in flower in Allouez (but not yet on UWGB): Trifolium hybridum (Alsike clover), T. repens (white clover), T. pratense (red clover).

Clintonia borealis (blue-bead lily) and Calla palustris (wild calla) in flower, Forest County.

May 30

Geranium maculatum (wild geranium) at about peak of flowering.

Prunus serotina (black cherry) in flower, UWGB

May 29 Baptisia bracteata ( ) in flower, UWGB.
May 28 The sun returns, high temperature in low 60's. Aralia nudicaulis (wild sarsaparilla) and Ranunculus recurvatus (hooked buttercup) in flower, UWGB.
May 27 Rain returns after one and a half sunny days. Green Bay has received 4.32 inches more than the average amount for this portion of May.
May 26

At last, a full sunny day. Tragopogon dubia (yellow goat's-beard) in flower, Allouez.

Argentina anserina (silverweed, formerly Potentilla anserina) in flower, City of Green Bay.

Erigeron philadelphicus (common fleabane), Lupinus perennis (lupine) and Euonymus alata (winged burning-bush) in flower, UWGB.

Spittlebugs on sweet clover, UWGB.

May 25 The rain finally cleared out and the last half of the day was sunny and mild. First day of flowering for Hesperis matronalis (dame's rocket), Viburnum lentago (nannyberry), Polygonatum pubescens (Solomon's-seal), Hydrophyllum virginianum (Virginia waterleaf) and Cornus stolonifera (red-osier dogwood) on UWGB campus.
May 24 Cool and rainy weather persists. Green Bay has had at least a trace of rain for each of the last 7 days (it rained on 17 of the first 23 days in May ), and a total of 6.49 inches of rain in May. That is about 4.52 inches higher than average for this point in May.
May 22 There have been flood warnings at several locations in Wisconsin over the last couple of days, due to persistent rain. Yesterday's high temperature was 56 F. Cool and rainy temperatures have dramatically slowed the development of the local plants.
May 21 I was out of town for a couple of days, but there has been very little development of the local phenology due primarily to cool, cloudy and rainy days. Cornus stolonifera (red-osier dogwood) is now in flower in Brown County.
May 16

Actaea rubra (red baneberry) and Galium aparine (cleavers) in flower UWGB.

Black Swallowtail butterfly observed on UWGB.

There will be a delay of a few days before I next update these observations.

May 15

Cold air moved in behind the rain. Green Bay reached a low temperature of 37 F this morning. Wausau reported 32 F and many other areas in northeastern Wisconsin reported freezing temperatures early this morning.

Comandra umbellata (bastard-toadflax) in flower, UWGB.

May 14

Prunus virginiana (choke cherry) in flower, Allouez.

Syringa vulgaris (lilac) beginning to flower, City GB.

Green Bay received a total of 1.94 inches of rain on May 12,13,14.

Rhinelander reported a low temperature of 27 F!

May 13 Aesculus glabra (Ohio buckeye) and Syringa vulgaris (lilac) in flower, both cultivated individuals, UWGB. A few early plants of Crataegus mollis (hawthorn or thornapple) have begun to flower in Brown County.
May 12

Malus pumila (apple, an escaped plant) in flower, UWGB. Several cultivated individuals also began flowering today.

A few Poulus tremuloides (quaking aspen) began dispersing seeds today, Barkhausen Waterfowl Preserve, Town of Suamico, Brown County.

May 11 The Prunus nigra (Canada wild plum) plant that began flower on May 3 is done flowering today. There is a rapid development of leaves on many species of trees and shrubs.
May 08

Medicago lupulina (black medick) in flower, City GB.

Uvularia grandiflora (large-flowered bellwort) in flower, Brown County, Town of Green Bay.

May 07 Ribes americana (American black currant), Smilacina stellata (starry false solomon's-seal), Prunus pensylvanica (pin cherry), Convallaria majalis (lily-of-the-valley), Zanthoxylum americanum (prickly ash) in flower, UWGB.
May 06

Amelanchier spicata (juneberry), Malus sp (flowering crab--cultivated), Sambucus pubens (red elderberry), Ribes missouriense (Missouri gooseberry), Prunus americana (wild plum) in flower, UWGB.

Observed incredible number of migrating songbirds incidental to other fieldwork on Plum Island including: Yellow-rumped Warbler (conservatively ~several hundred), Palm Warbler (~10-15), Northern Parula (~10-15), Black-throated Green Warbler (~30-50), Cape May Warbler, Blackburnian Warbler, Nashville Warbler, Scarlet Tanager, Red-headed Woodpecker, Swamp Sparrow (<5), Lincoln's Sparrow (2), White-throated Sparrow (<10), Rose-breasted Grosbeak (2). 48 species observed in total, all from northern 1/3 of island (approx. 100 acres)
Plum Island, Door County (Jake Ivan).

May 05

Salix exigua (= S. interior, sandbar willow) in flower (anthesis), UWGB.

Our first ruby-throated hummingbird at the feeder this morning, and house wren singing in the yard. There seems to be a new batch of white-throated sparrows this morning; slate-colored juncos have apparently moved on, as I have not seen one for several days, Town of Cooperstown, Manitowoc County (Joel Trick).

May 04

Amelanchier sanguinea (juneberry) in flower, UWGB.

I saw a large snapping turtle crossing the road, UWGB.

Here's a phenology item I'd rather not have experienced. After many years in the outdoors in northeastern Wisconsin I collected my first deer tick today -- or more precisely, it collected me. This is the tick well known for its ability to transmit Lyme Disease. On the plus side, I did get photos of it. Fortunately, the "wood ticks" that are so common in Wisconsin DO NOT transmit Lime Disease.

May 03

Viola pubescens (yellow violet) in flower, UWGB.

Populus tremuloides (quaking aspen) and Acer negundo (box elder) leaves have grown large enough to be conspicuously green in forests, UWGB.

The low temperature was 27° F in Green Bay this morning. I had to scrape the frost from my windshield.

May 02

Prunus nigra (Canadian wild plum) and Arisaema triphyllum (jack-in-the-pulpit) in flower, UWGB.

The low temperature was 31° F in Green Bay this morning.

May 01

Ostrya virginiana (ironwood), (Ranunculus abortivus) small-flowered crowfoot, Fraxinus pennsylvanica (green ash), Celtis occidentalis (hackberry, cultivated individual) in flower, UWGB.

Fragaria virginiana (wild strawberry) in flower, City of Green Bay and Town of New Denmark, Brown County.

Good numbers of Palm Warblers and Black-throated Green Warblers feeding around streams and spring ponds, Town of Polar, Langlade County (Steve Janke).

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Last updated on May 20, 2015