biodiversity homepage      

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 2011 Mouse-over the photo for the identity of the subject

May 31

Osmorhiza longistylis (long-styled sweet cicely) in flower.

Most Trillium grandiflorum (big white trillium) flowers have turned pink and are quickly drying up.

Junebugs out, Oconto County, Pensaukee (Tom Erdman).

May 30 Hydrophyllum virginianum (Virginia water-leaf) in flower.
May 28 Podophyllum peltatum (May-apple) in flower.
May 27 Lupinus perennis (wild lupine) in flower, planted prairie, Cofrin Arboretum, UW-Green Bay.
May 26 Pinus banksiana (jack pine) in flower (anthesis), planted UW-Green Bay.
May 25 Convallaria majalis (lily of the valley) in flower, over-grown by young woods, not near house or in lawn.
May 24 Tsuga canadensis (eastern hemlock) has begun to flower (anthesis), City of Green Bay. Last year this same tree began to flower on May 6.
May 23

Monarch butterfly, UWGB.

The very common alien honeysuckly Lonicera xbella (showy bush honeysuckle) has begun to flower.

May 22 Syringa vulgaris (lilac) and Crataegus mollis (downy hawthorn) in flower.
May 21 Trillium cernuum (nodding trillium) in flower. This is the first day that Trillium grandiflorum (big white trillium) petals show a tinge of pink as they begin to senesce.
May 20

Actaea rubra (bishop's-cap) white banedberry) in flower.

Mitella diphylla (in flower, Marinette County; Picea glauca (white spruce) in flower (anthesis) Marinette County

May 19 "Escaped" Malus pumila (apple) flowering City of Green Bay.
May 18 American Toads area at about the peak of calling (through 5/21) on our pond, Allouez, Brown County.
May 17

Another cold night, with a low of 34° F in Green Bay and frost and freezing conditions in Laona at 31° and Eagle River at 28°.

Ostrya virginiana (hop-hornbeam; ironwood) in flower (anthesis).

Snapping turtle out for egg laying, Oconto County (Tom Erdman)

May 16

prairieGreen Bay's morning low temperature fell to 37° F. and there was frost farther north and west, 31° at Laona, 29° at Eagle River. The day is clear and sunny with highs only in the low to mid 50's.

Ranunculus abortivus (small-flowered buttercup ) in flower.

May 15

A very windy day in Green Bay with gusts over 40 mph.

Fraxinus pennsylvanica (green ash) has begun to flower (anthesis), Brown County. Also Celtis occidentalis (northern hackberry) in flower.

May 14 Cloudy, rainy with high temperature of 53° F in Green Bay and windy.
May 13 Rain in the afternoon, but a few new species in flower, including some flowering crabapples in Green Bay and some Amelanchier sanguinea (juneberry) in Oconto County.
May 12

Sambucus racemosa (red elderberry) is in flower in woods, City of Green Bay. Also the weedy species Thlaspi arvensis (field penny-cress) is in flower widely in the Green Bay area.

Taraxacum officinale (dandelion) is at about the peak of its flowering, City of Green Bay.

May 11

May has been mostly below average temperatures so far and there has been at least a little rain on 6 of the first 10 days. The development of local plants continues to lag behind last year's events by about 2-3 weeks.

First flowering for 3 species of Ribes, R. cynosbati (eastern prickly gooseberry), R. missouriense (Missouri gooseberry) and Ribes rubrum (garden red currant).

May 10 First day of flower for Fragaria virginiana (wild strawberry). Also first day of flower for Amelanchier arborea (downy juneberry) and Waldsteinia fragarioides (barren strawberry), both planted in the Lenfesty courtyard of MAC HAll at UW-Green Bay.
May 09 First day of flower for Veronica arvensis (corn speedwell) a common though very small weed of lawns.
May 07 Trillium grandiflorum (big white trillium) began flowering--only two fully open flowers seen.

May 06

Today we saw the first new Canada Geese goslings geeseon our neighborhood pond in Allouez (photo May 8). I hear that the first sighting of goslins was about May first at the Bay Beach Wildlife Sanctuary.

May 04

A sunny, mild day, but still not much sign of spring, UW-Green Bay Cofrin Arboretum.

If you needed any convincing that this is a late spring, compare these two photos both taken on May 4 on UW-Green Bays's Cofrin Arboretum. Last year's photo on the left and this year on the right. Here's another comparison at UWGB's Prairie Pond. The dates vary from place to place and from one species to another, but in general we seem to be about 3 weeks later than last year.

May 03 Coudy and cool most of the day with a morning low temperature of 35° F, but somehow a couple of new species began to flower (anthesis): a few Populus deltoides (eastern cottonwood) on disturbed upland sites (but not plants in the more normal wet sites) and a few Acer negundo (box elder, Allouez). The box elder is 24 days later than last year and the cottonwoods are 30 days later than last year!
May 01 First day of flower at my usual sites on UWGB for Erythronium album (white trout lily), Erythronium americanum (yellow trout lily), Cardamine concatenata (cut-leaved toothwort), Claytonia virginica (spring beauty). Later sites for Caltha palustris (marsh marigold) are also starting to flower now. The late snow and cool, cloudy weather have delayed flowering dates considerably--up to about 3 weeks later than last year.

© 2001-2004 The Cofrin Center for Biodiversity and the University of Wisconsin Green Bay, All Rights Reserved
Last updated on May 20, 2015