From: Robin Scribailo    To: breitin@jorsm.com    Sent: Thursday, December 09, 2004 2:40 PM     Subject: Silver Lake

What are the two or three most abundant native aquatic plants in Silver Lake? 

The most abundant aquatic plants are Nuphar advena , yellow water-lily or spatterdock, Myriophyllum verticillatum (Eurasian Water-milfoil) followed by Potamogeton pusillus (slender pondweed).

What are one or two invasive aquatic species found in Silver Lake?

Yellow water-lily is very invasive although native. Because of the shallowness of the lake it covers over sixty percent of the surface area. Myriophyllum spicatum or Eurasian water-milfoil is present in the lake and is exotic but is only found in small amounts since it is dominated by the native water-milfoil Myriophyllum verticillatum.  

Are there any rare or special aquatic species of note in Silver Lake?  If so, what are they?

There are several rare aquatic plant species in the lake. These include Myriophyllum verticillatum (state-threatened), Zannichellia palustris (state-threatened), Stuckenia filiformis var. occidentalis (state-endangered) and Ceratophyllum echinatum- spiny coontail (state-rare)

 

The high density of fingernail clams is unusual and is an indicator of good water quality.  The lake is unusual in having a pH of slightly less than 7.0 making it slightly acidic.  Almost all lakes and wetlands in the region are distinctly alkaline with a Ph of 8.0 or above.  This is undoubtedly becuase of the extensive peat areas that release acidity. This is countered by the groundwater input which is likely alkaline.

AQUATIC PLANT SPECIES LIST FOR SILVER LAKE

 

Compiled by Dr. Robin Scribailo

And Mitchell Alix (Purdue North Central)

 

November 23 /2004

 

C          Genus and Species                    Common Name

 

10         Brasenia schreberi                     Water shield

 

5           Ceratophyllum demersum            Coontail

 

10        Ceratophyllum echinatum            Spiny Coontail                                   State Rare

 

Chara braunii                            Muskgrass                                          

 

Chara foliolosa                         Muskgrass

 

Chara globularis                       Muskgrass

 

5          Elodea Canadensis                    Canada waterweed

 

8           Heteranthera dubia                  Water Stargrass

 

5          Lemna minor                              Duckweed

 

7          Lemna trisulca                           Forked Duckweed

 

Myriophyllum spicatum               Eurasian milfoil

 

10         Myriophyllum verticillatum         Whorled Water-milfoil             State Rare

 

6          Najas flexilis                              Slender Naiad

 

Nitella flexilis                              Musk Grass

 

7            Nuphar advena                            Spatterdock

 

10            Potamogeton amplifolius            Large-leaved Pondweed

 

7            Potamogeton illinoensis                Illinois Pondweed

 

7            Potamogeton pusillus                     Lesser Pondweed

 

8            Potamogeton zosteriformis            Flatstem Pondweed

 

Riccia fluitans                                  Slender Riccia              

 

Ricciocarpus natans                        Purple-fringed Riccia

 

7            Spirodela polyrhiza                        Greater Duckweed

 

10            Stuckenia filiformis subsp.           Threadleaf Pondweed              State Endangered

 

7            Stuckenia pectinata                       Sago Pondweed

 

10            Utricularia gibba                         Humped Bladderwort

 

9            Utricularia vulgaris                      Common Bladderwort

 

7            Vallisneria Americana                    Tapegrass

 

7              Wolffia sp.                                     Duckmeal

 

10            Zannichellia palustris                    Horned Pondweed                    State Endangered

 

 

30 species total, 1 exotic, 6 nonvascular (2 liverworts and 4 charophytes), 29 vascular

 

Mean coefficient of conservatism = 4.9

Floristic Quality Index of 37.3

 

Other notable species:

 

16 muskrat hutches and 2 beaver hutches

 

Great Abundance of Fingernail clams – Sphaeriidae

Excellent Indicators of Water Quality