Isoetes mississippiensis

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Mississippi quillwort
 
Scientific classification
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I. mississippiensis
Binomial name
Isoetes mississippiensis

The Mississippi Quillwort (Isoetes mississippiensis) is a small aquatic pteridophyte from the family Isoetaceae[1]. It can be found in the southern part of Mississippi in the tributaries of the Pearl River. Isoetes mississippiensis occurs in persistent, sluggish streams in the southern part of Mississippi. Other plants that occupy the same habitat include the graminoids such as rushes and panicgrass. [2] Isoetes mississippiensis only occurs in two known areas, neither of which occur in protected areas.[2]

The rootstock of Isoetes mississippiensis is brown, bilobed, subglobose, and measures between 0.5-1.0cm long and 1.0-1.5cm wide. [2] The sporophylls are a bright green which darkens with age and becomes pale towards the base. The sporophylls are also spirally arranged and can grow to 40cm long and 2.0mm wide at the mid-length.[2] It's sporangium are ovate, with most being between 4-10mm long and 4-5mm wide. It is distinct from other Isoetes species due to it having a chromosome count of 2n=22, the presence of laevigate megaspore ornamentation [3], and the differences of it's habitat in comparison to similar species in the genus Isoetes.[2]


References

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  1. ^ Alston, A. (1959). Isoetaceae. Flora Malesiana - Series 2, Pteridophyta, 1(1), 62–64.
  2. ^ a b c d e Schafran PW, Leonard SW, Bray RD, Taylor WC, Musselman LJ (2016) Isoetes mississippiensis: A new quillwort from Mississippi, USA. PhytoKeys 74: 97-106. https://doi.org/10.3897/phytokeys.74.10380
  3. ^ Taylor, W. (1993). MEGASPORE WALL ULTRASTRUCTURE IN ISOETES. American Journal of Botany, 80(2), 165–171. https://doi.org/10.1002/j.1537-2197.1993.tb13785.x