Isoetes engelmannii
Encyclopedia
Isoetes engelmannii, commonly known as Engelmann's quillwort or Appalachian quillwort (not to be confused with the newly described Isoetes appalachiana
), is an aquatic pteridophyte
and is the most widely distributed species of its genus in eastern North America
. Its range extends from Ontario
in the north, south to Florida
and west Arkansas
and Missouri
.It can be found from April to October in temporary pools, bogs, marshes, stream edges, swamps and along wet roadsides.
. The rootstock (rhizomorph) is almost globose and normally has 2 lobes. The bright green, pliable leaves
are evergreen and become paler towards the base and gradually taper to a point at the apex. They are typically about 60 cm in length, but they range from 10cm up to 90 cm long. They are arranged spirally. The wall of the sporangium
typically lacks any pigment, but sometimes it may be streaked with brown. The velum covers less than a quarter of the sporangium. The megaspore
s are white in colour and measure 400 to 560 μm in diameter. Their texture is reticulate (i.e. net-like) and the lamellate ridges are unbroken. The girdle that runs between these ridges is obscured by the heavy reticulation. The microspore
s are grey in colour, measure 20 to 30 μm in diameter, and are smooth to papillose (i.e. with minute projections) in texture. The spores mature in the summer. The chromosome
number is 2n = 22.
, more so than any other species in the genus occurring in that region. Within Canada
it is only found in the extreme southern portions of Ontario
. In the United States
its primary range begins in New Hampshire
in the northeast and west to New York
. There are also several outlying populations farther west in western Michigan
. The range extends south along the Appalachians to the extreme north of Florida
, and also continues west in the mountains to the northeastern tip of Mississippi
, the northeastern tip of Arkansas
and southeastern Missouri
, and north to the southern portions of Indiana
and Illinois
. Another disjunct population exists in northeastern Ohio
.
It can be found from April to October in habitats that include temporary pools, bogs, marshes, in streams or along their edges, swamps and along wet roadsides in ditches. It is also grows as an emergent in shallow lakes and ponds.
Isoetes appalachiana
Isoetes appalachiana, commonly known as the Appalachian quillwort , is an aquatic pteridophyte that is widely distributed in the eastern United States...
), is an aquatic pteridophyte
Pteridophyte
The pteridophytes are vascular plants that produce neither flowers nor seeds, and are hence called vascular cryptogams. Instead, they reproduce and disperse only via spores. Pteridophytes include horsetails, ferns, club mosses, and quillworts...
and is the most widely distributed species of its genus in eastern North America
North America
North America is a continent wholly within the Northern Hemisphere and almost wholly within the Western Hemisphere. It is also considered a northern subcontinent of the Americas...
. Its range extends from Ontario
Ontario
Ontario is a province of Canada, located in east-central Canada. It is Canada's most populous province and second largest in total area. It is home to the nation's most populous city, Toronto, and the nation's capital, Ottawa....
in the north, south to Florida
Florida
Florida is a state in the southeastern United States, located on the nation's Atlantic and Gulf coasts. It is bordered to the west by the Gulf of Mexico, to the north by Alabama and Georgia and to the east by the Atlantic Ocean. With a population of 18,801,310 as measured by the 2010 census, it...
and west Arkansas
Arkansas
Arkansas is a state located in the southern region of the United States. Its name is an Algonquian name of the Quapaw Indians. Arkansas shares borders with six states , and its eastern border is largely defined by the Mississippi River...
and Missouri
Missouri
Missouri is a US state located in the Midwestern United States, bordered by Iowa, Illinois, Kentucky, Tennessee, Arkansas, Oklahoma, Kansas and Nebraska. With a 2010 population of 5,988,927, Missouri is the 18th most populous state in the nation and the fifth most populous in the Midwest. It...
.It can be found from April to October in temporary pools, bogs, marshes, stream edges, swamps and along wet roadsides.
Description
Isoetes engelmannii is an emergant aquatic perennial pteridophytePteridophyte
The pteridophytes are vascular plants that produce neither flowers nor seeds, and are hence called vascular cryptogams. Instead, they reproduce and disperse only via spores. Pteridophytes include horsetails, ferns, club mosses, and quillworts...
. The rootstock (rhizomorph) is almost globose and normally has 2 lobes. The bright green, pliable leaves
Leaf
A leaf is an organ of a vascular plant, as defined in botanical terms, and in particular in plant morphology. Foliage is a mass noun that refers to leaves as a feature of plants....
are evergreen and become paler towards the base and gradually taper to a point at the apex. They are typically about 60 cm in length, but they range from 10cm up to 90 cm long. They are arranged spirally. The wall of the sporangium
Sporangium
A sporangium is an enclosure in which spores are formed. It can be composed of a single cell or can be multicellular. All plants, fungi, and many other lineages form sporangia at some point in their life cycle...
typically lacks any pigment, but sometimes it may be streaked with brown. The velum covers less than a quarter of the sporangium. The megaspore
Megaspore
Megaspores, also called macrospores, are a type of spore that is present in heterosporous plants. These types of plants have two spore types, megaspores and microspores. Generally speaking, the megaspore, or large spore, germinates into a female gametophyte, which is fertilized by sperm produced...
s are white in colour and measure 400 to 560 μm in diameter. Their texture is reticulate (i.e. net-like) and the lamellate ridges are unbroken. The girdle that runs between these ridges is obscured by the heavy reticulation. The microspore
Microspore
In biology, a microspore is a small spore as contrasted to the larger megaspore.In botany, microspores develop into male gametophytes, whereas megaspores develop into female gametophytes. The combination of megaspores and microspores is found only in heterosporous organisms...
s are grey in colour, measure 20 to 30 μm in diameter, and are smooth to papillose (i.e. with minute projections) in texture. The spores mature in the summer. The chromosome
Chromosome
A chromosome is an organized structure of DNA and protein found in cells. It is a single piece of coiled DNA containing many genes, regulatory elements and other nucleotide sequences. Chromosomes also contain DNA-bound proteins, which serve to package the DNA and control its functions.Chromosomes...
number is 2n = 22.
Distribution and habitat
Isoetes engelmannii is widely distributed in eastern North AmericaNorth America
North America is a continent wholly within the Northern Hemisphere and almost wholly within the Western Hemisphere. It is also considered a northern subcontinent of the Americas...
, more so than any other species in the genus occurring in that region. Within Canada
Canada
Canada is a North American country consisting of ten provinces and three territories. Located in the northern part of the continent, it extends from the Atlantic Ocean in the east to the Pacific Ocean in the west, and northward into the Arctic Ocean...
it is only found in the extreme southern portions of Ontario
Ontario
Ontario is a province of Canada, located in east-central Canada. It is Canada's most populous province and second largest in total area. It is home to the nation's most populous city, Toronto, and the nation's capital, Ottawa....
. In the United States
United States
The United States of America is a federal constitutional republic comprising fifty states and a federal district...
its primary range begins in New Hampshire
New Hampshire
New Hampshire is a state in the New England region of the northeastern United States of America. The state was named after the southern English county of Hampshire. It is bordered by Massachusetts to the south, Vermont to the west, Maine and the Atlantic Ocean to the east, and the Canadian...
in the northeast and west to New York
New York
New York is a state in the Northeastern region of the United States. It is the nation's third most populous state. New York is bordered by New Jersey and Pennsylvania to the south, and by Connecticut, Massachusetts and Vermont to the east...
. There are also several outlying populations farther west in western Michigan
Michigan
Michigan is a U.S. state located in the Great Lakes Region of the United States of America. The name Michigan is the French form of the Ojibwa word mishigamaa, meaning "large water" or "large lake"....
. The range extends south along the Appalachians to the extreme north of Florida
Florida
Florida is a state in the southeastern United States, located on the nation's Atlantic and Gulf coasts. It is bordered to the west by the Gulf of Mexico, to the north by Alabama and Georgia and to the east by the Atlantic Ocean. With a population of 18,801,310 as measured by the 2010 census, it...
, and also continues west in the mountains to the northeastern tip of Mississippi
Mississippi
Mississippi is a U.S. state located in the Southern United States. Jackson is the state capital and largest city. The name of the state derives from the Mississippi River, which flows along its western boundary, whose name comes from the Ojibwe word misi-ziibi...
, the northeastern tip of Arkansas
Arkansas
Arkansas is a state located in the southern region of the United States. Its name is an Algonquian name of the Quapaw Indians. Arkansas shares borders with six states , and its eastern border is largely defined by the Mississippi River...
and southeastern Missouri
Missouri
Missouri is a US state located in the Midwestern United States, bordered by Iowa, Illinois, Kentucky, Tennessee, Arkansas, Oklahoma, Kansas and Nebraska. With a 2010 population of 5,988,927, Missouri is the 18th most populous state in the nation and the fifth most populous in the Midwest. It...
, and north to the southern portions of Indiana
Indiana
Indiana is a US state, admitted to the United States as the 19th on December 11, 1816. It is located in the Midwestern United States and Great Lakes Region. With 6,483,802 residents, the state is ranked 15th in population and 16th in population density. Indiana is ranked 38th in land area and is...
and Illinois
Illinois
Illinois is the fifth-most populous state of the United States of America, and is often noted for being a microcosm of the entire country. With Chicago in the northeast, small industrial cities and great agricultural productivity in central and northern Illinois, and natural resources like coal,...
. Another disjunct population exists in northeastern Ohio
Ohio
Ohio is a Midwestern state in the United States. The 34th largest state by area in the U.S.,it is the 7th‑most populous with over 11.5 million residents, containing several major American cities and seven metropolitan areas with populations of 500,000 or more.The state's capital is Columbus...
.
It can be found from April to October in habitats that include temporary pools, bogs, marshes, in streams or along their edges, swamps and along wet roadsides in ditches. It is also grows as an emergent in shallow lakes and ponds.