Part 7 - UNC Herbarium

POTAMOGETONACEAE 932
Fernald – F; > P. berchtoldii var. tenuissimus (Mertens & Koch) Fernald – F; < P. pusillus – G, GW, S, Z; = P. pusillus ssp.
tenuissimus (Mertens & Koch) R.R. Haynes & C.B. Hellquist – FNA, K]
Potamogeton robbinsii Oakes, Fern Pondweed. Pd (VA): muddy waters; rare (VA Rare). August-September. Nova Scotia
and Prince Edward Island west to Keewatin and AK, south to n. VA, n. IL, s. MN, CO, UT, and CA; disjunct in s. AL. [= C, F,
FNA, G, K, Z]
Potamogeton spirillus Tuckerman, Northern Snailseed Pondweed. Cp (VA): quiet waters; rare (VA Rare). July-
November. Newfoundland west to Manitoba, south to e. VA, n. OH, n. IA, and se. NE. [= C, F, FNA, G, K, Z]
Potamogeton strictifolius A. Bennett, Straightleaf Pondweed. Mt (VA): calcareous waters; rare (VA Rare). July-
September. Newfoundland west to Yukon, south to w. VA, n. IL, WY, and n. UT. [= C, FNA, G, K, W, Z; > P. strictifolius var.
strictifolius – F; > P. strictifolius var. rutiloides Fernald – F; > P. longiligulatus Fernald – F]
Potamogeton tennesseensis Fernald, Tennessee Pondweed. Mt (VA), {NC?}: quiet or flowing water; rare (VA Rare).
Late May-September. PA and OH south to w. VA, and se. TN. [= F, FNA, K, W; < P. epihydrus – Z, in part]
Potamogeton zosteriformis Fernald, Flatstem Pondweed. Cp, Mt (VA): quiet waters; rare (VA Rare). July-September.
Newfoundland west to AK, south to n. VA, n. IL, KS, UT, and CA. [= C, F, FNA, G, K, Z]
Potamogeton alpinus Balbis, Red Pondweed, south to e. PA (Rhoads & Klein 1993). [= FNA, G, K, Z; > P. alpinus var.
tenuifolius (Rafinesque) Ogden – C, F; > P. tenuifolius Rafinesque]
Potamogeton floridanus Small, Florida Pondweed, is apparently endemic to blackwater rivers of the Panhandle of FL.
Considering the under-collection of Potamogeton, it should be sought elsewhere. [= FNA, S; < P. natans – Z]
Potamogeton friesii Ruprecht, Fries's Pondweed, south to c. PA (Rhoads & Klein 1993). (VA Watch List) [= C, F, FNA,
G, K, Z]
Potamogeton obtusifolius Mertens & Koch, south to MD, NJ, and PA. [= C, F, FNA, G, K] {not keyed at this time;
synonymy incomplete}
Potamogeton praelongus Wulfen, Whitestem Pondweed, south to MD and nw. PA (Rhoads & Klein 1993). [= C, F, FNA,
G, K, Z]
Potamogeton richardsonii (Bennett) Rydberg, Richardson Pondweed, south to DE, MD, and PA. [= C, F, FNA, G, K, Z]
Potamogeton vaseyi J.W. Robbins, Vasey Pondweed, south to se. and sc. PA (Rhoads & Klein 1993). [= C, F, FNA, G, K,
Z]
Stuckenia C. Börner 1912 (Sago-pondweed)
A genus of about 10 species, nearly cosmopolitan. This genus should be called Stuckenia, which has priority over Coleogeton.
References: Haynes & Hellquist in FNA (2000); Les & Haynes (1996)=Z; Haynes, Les, & Král (1998)=Y; Wiegleb & Kaplan
(1998)=X.
1 Leaves minutely acute (use 10× magnification); achenes usually 3-4.5 mm long, with the style persistent as a very short
beak ......................................................................................................................................................................... S. pectinata
1 Leaves minutely rounded or retuse (use 10× magnification); achenes usually 2-3 mm long, with the sessile stigma persistent
as a bump............................................................................................................................................ [S. filiformis ssp. alpine]
Stuckenia pectinata (Linnaeus) C. Börner, Sago-pondweed. Cp (NC, SC, VA), Mt, Pd (VA), {GA}: calcareous or brackish
waters of ponds, lakes, estuaries, sounds; uncommon. June-September. The species is irregularly cosmopolitan. [= FNA, K, Y;
= Potamogeton pectinatus Linnaeus – RAB, C, F, G, GW, S, W, X; = Coleogeton pectinatus (Linnaeus) D.H. Les & R.R.
Haynes – Z]
Stuckenia filiformis (Persoon) C. Börner ssp. alpina (Blytt) R.R. Haynes, D.H. Les, & M. Král, Threadleaf Pondweed,
approaches our area in se. and sc. PA. [= FNA, K, Y; = Potamogeton filiformis Persoon var. alpinus (Blytt) Ascherson &
Graebner; > Potamogeton filiformis Persoon var. borealis (Rafinesque) H. St. John – C, F, G; < Potamogeton filiformis – X; =
Coleogeton filiformis (Persoon) D.H. Les & R.R. Haynes ssp. alpinus (Blytt) D.H. Les & R.R. Haynes – Z]
RUPPIACEAE Horaninow ex Hutchinson 1934 (Wigeon-grass Family)
A family of a single genus and 1-10 species. References: Haynes (1978)=Z; Haynes in FNA (2000); Haynes, Holm-Nielsen, &
Les in Kubitzki (1998b).
Ruppia Linnaeus (Wigeon-grass)
A genus of 1-10 species, nearly cosmopolitan. References: Haynes (1978)=Z; Haynes in FNA (2000); Haynes, Holm-Nielsen, &
Les in Kubitzki (1998b).