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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.

April 2005

Apr 30

Many thanks to the students from UWGB's Round River Alliance and the Conservation Biology class who helped pull Garlic Mustard today on UWGB and in neighboring forests. Garlic mustard (Alliaria petiolata) is an invasive alien plant species that, left unchecked, will take over the forest floor and displace our native plant species. To learn more about garlic mustard visit our invasive plants web site.

Fraxinus pennsylvanica (green ash) is in flower today (pollen released), Brown County, Allouez.

Viola blanda (sweet white violet) and at least 2 species of Amelanchier (juneberries) in flower, Shawano County.

Apr 28

I haven't abandoned this listing--the cold, cloudy weather has brought development of the plants to a crawl. Daytime temps have been in 40's and 50's with low temperature mostly in the low 30's since the 21st. Many species are poised to flower as soon as sunny, warm weather returns and many of the spring and early summer plants are recognizeable as the emerge.

The U.S. Army Corps of Engineers recent data show the water level in Lake Michigan is up about 6 inches from last year at this date.

Apr 26 Amelanchier arborea (downy Juneberry, common shadbush) is in flower in our Lenfesty courtyard, UWGB. Based on plants I saw last Sunday, I suspect that the early Juneberries are in flower in the wild also. Wisconsin is home to 6 species of Juneberries and they can be very difficult to distinguish. A. sanguinea and A. laevis appear to be the most common species in the Green Bay area.
Apr 25

Painted Lady butterfly observed on UWGB.

Veronica arvensis (corn speedwell), Thlaspi arvense (field pennycress) in flower, UWGB.

Apr 24

Ribes tristte (swamp red currant) in flower, Brown County.

Chamaedaphne calyculata (leather-leaf) in flower, Shawano County.

Apr 23 Cardamine concatenata (was Dentaria laciniata, cut-leaved toothwort) in flower, UWGB.
Apr 22

Taraxacum officinale is now numerous in some lawns, but is still not close to peak flower, City Green Bay.

White pelican, Green Bay, lower Fox River (Kate Hutton).

Apr 21

The first flowers are open for Cardamine douglassii (limestone bitter-cress), Asarum canadense (wild ginger) and Euphorbia cyparissias (cypress spurge), UWGB.

Betula papyrifera (paper birch)in flower (dispersing pollen), UWGB.

American Toads calling, UWGB.

Populus tremuloides (quaking aspen), Acer negundo (box elder), Lonicera xbella (showy bush honeysuckle) and Ribes americana (American black currant) are rapidly leafing out in the Green Bay area.

Apr 20

A much-needed rain fell in northeastern Wisconsin last night, with 0.86 inches before midnight. There have been grass and brush fires in northeastern Wisconsin every day for the last week or more.

This morning I heard the first Leopard Frogs calling, Brown County, City of Green Bay.

One Acer platanoides (Norway maple) tree is in flower in the lawn near MAC Hall.

Apr 19

Capsella bursa-pastoris (shepherd's-purse) in flower, UWGB.

Taxus cuspidata (Japanese yew) in flower (pollen dispersed), UWGB. This species is strictly horticultural here and does not grow out of cultivation.

First cabbage butterfly I've seen, UWGB.

Salix bebbiana (Bebb's willow) in flower (pollen dispersed), City of Green Bay.

Heard first leopard frog calling this morning. This evening, first American toads and Gray Tree Frogs calling following thunderstorms. Unusually warm weather for the past few days has resulted in rapid leaf expansion in choke cherry, black raspberry, and trembling aspen, Manitowoc County, Town of Cooperstown (Joel Trick).

Several people on The Wisconsin Birding List report the departure of overwintering juncos; numbers at our feeders have declined, but several juncos were still present as of this morning, Manitowoc County, Town of Cooperstown (Joel Trick).

Apr 18

Glechoma hederacea (gill-over-the-ground) in flower, UWGB.

Barbarea vulgaris (yellow rocket) Brown County, Bellevue.

Today is the first day I've seen tiger beetles (Cicindela sexguttata, I think) on the arboretum trails (Mike Draney).

Apr 17

Erythronium albidum (white trout-lily) in flower, UWGB. [the advent of cold and cloudy weather has kept further flowering of this species to a minimum until after May 3, gf]

Acer negundo (box elder) in flower (pollen dispersed), City GB.

There are also reports of Sanguinaria canadensis (bloodroot) in flower in Brown County.

Lake Sturgeon were spawning in the Wolf River today, but I don't know when they started.

Apr 16

Carex pensylvanica (Pennsylvania sedge) in flower (releasing pollen), UWGB.

Isopyrum biternatum (false rue-anemone), Claytonia virginica (spring beauty) in flower, UWGB.

Equisetum arvense (common horsetail) releasing spores, UWGB.

Sanguinaria canadensis (bloodroot) in flower, Brown County (Kathy Groves).

Wood turtle, Oconto County (Tom Erdman).

Apr 15

Juniperus chinensis (Chinese Juniper) in flower (anthers releasing pollen), UWGB.

Populus deltoides (eastern cottonwood) in flower (releasing pollen), UWGB. These are plants on disturbed soil at UWGB and at various places in City of Green Bay. Plants in the more natural wet sites are a bit later. My long-term phenology tree for P. deltoides at UWGB began to release pollen 04/16.

Forsythia (Forsythia, or golden bells) in flower, DePere (Kathy Groves).

Apr 14

Larix decidua (European Larch) horticultural planting is in flower (pollen released), UWGB.

Drab verna (spring whitlow-grass), in flower, Brown County.

Apr 13

Garter Snake out and about, Brown County (Kathy Groves).

Anemone acutiloba, formerly Hepatica acutiloba (sharp-lobed hepatica) in flower, Brown County (Kathy Groves).

First Red Admiral butterfly report, Brown County, Nick Walton.

Painted Turtle sunning on a log in the river, and Wood ducks return, Shawano (Joel Whitehouse).

Apr 12 Salix humilis (prairie willow) and Androsace occidentalis (rock-jasmine)in flower (pollen dispersed), UWGB.
Apr 11 Populus grandidentata (big-tooth aspen) in flower (anthesis), UWGB.
Apr 10 Acer rubrum (Red Maple) in flower (anthesis), UWGB.
Apr 09

Suckers (fish) are moving up Mahon Creek, to begin the spawning season, UWGB.

Anemone acutiloba, formerly Hepatica acutiloba (Sharp-lobed Hepatica) in flower, Shawano County (Joel Whitehouse).

Apr 08 Ulmus americana (American elm), Ulmus pumila (Siberian elm) and Salix discolor (pussy wiillow) in flower (anthesis), UWGB.
Apr 07

The first flowers of Caltha palustris (marsh marigold) are open, Brown County. These plants are in flowing springs that keep the ground from freezing in winter and give the plants a headstart in the spring. Plants not in springs may not flower for another week or two.

Mourning Cloak butterfly observed, City of Green Bay (Heather Gentry).

Wood Frogs calling in Shawano Co (Joel Whitehouse).

Apr 06 Thuja occidentalis (white cedar; arbor vitae) has begun to flower (anthesis) on upland sites in Green Bay. The flowering cones are so small that they are often overlooked.
Apr 05 The ice is off Prairie Pond at UWGB today. It froze fully and stayed frozen Dec 14, for an ice-covered period of 112 days. Last year the ice came off Prairie Pond March 26. The average date is March 27 (for 9 years of data).
Apr 04 Spring Peepers (frogs) calling at night, Pensaukee, Oconto County (Tom Erdman).
Apr 03

Populus tremuloides (Quaking Aspen) in flower (anthesis), UWGB.

Taraxacum officinale (dandelion) in flower, UWGB. These are the first flowering plants of dandelion that I have seen this year. The site is a lawn on a south facing slope at the base of a brick wall, where the soil warms much earlier than the surrounding lawns and fields. The average date for this population to flower is April 9, about 15 days earlier than dandelions in the open lawn away from buildings.

Apr 02 Corylus americana (American hazelnut) in flower (anthesis) UWGB.
Apr 01

Alnus rugosa (Speckled alder or tag alder) in flower (anthesis), Brown County, Baird Creek area.

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Last updated on April 15, 2014