Potamogeton lucens

Potamogeton lucens
Scientific classification
Kingdom:	Plantae
(unranked):	Angiosperms
(unranked):	Monocots
Order:	Alismatales
Family:	Potamogetonaceae
Genus:	Potamogeton
Species:	P.lucens
Binomial name
Potamogeton lucens L.
Synonyms
Buccaferrea lucida Bubani Potamogeton acuminatus Schumach. Potamogeton americanus Roem. & Schult. Potamogeton angustifolius Bercht. & J.Presl. ex Opiz Potamogeton caudatus Seidl ex Opiz Potamogeton coriaceus (Nolte ex Mert. & W.D.J.Koch) Fryer Potamogeton corniculatus Schur Potamogeton cornutus J.Presl. & C.Presl. Potamogeton dentatus Hagstr. Potamogeton gaudichaudii Cham. & Schltdl. Potamogeton gramineus subsp. zizii (Mert. & W.D.J.Koch) K.Richt. Potamogeton lanceolatus Eichw. Potamogeton lindenbergii Lehm. ex Graebn. Potamogeton longifolius J.Gay ex Poir. Potamogeton lucidus Gueldenst. Potamogeton macrophyllus Wolfg. Potamogeton nitens Willd. ex Cham & Schltdl. Potamogeton proteus Cham & Schltdl. Potamogeton pseudolongifolius Papch. Potamogeton rotundifolius Schultz Potamogeton sinicus Migo Potamogeton teganumensis (Makino) Makino Potamogeton volhynicus Besser ex Roem. & Schult. Potamogeton zizii Mert. & W.D.J.Koch Potamogeton zizii Koch ex Roth Spirillus lucens (L.) Nieuwl. Spirillus zizii (Mert. & W.D.J.Koch) Nieuwl.

Potamogeton lucens, or shining pondweed, is an aquatic perennial plant native to Eurasia and North Africa. It grows in relatively deep, still or slow-flowing, calcareous freshwater habitats.

Shining pondweed is a large plant with robust creeping rhizomes and long, terete, branching stems, typically up to 2.5 m but exceptionally to 6 m. The leaves are large, 75–200 mm (exceptionally more) long and 25–65 mm wide, 2-6 times as long as broad; as with the smaller P. gramineus, the leaves on the branches are smaller than those on the main stem. The leaves are pale green or yellowish, translucent, shiny with distinctive netted veining, minutely denticulate margins, and a short petiole of 1–12 mm. Floating leaves are absent.

Flowers appear between June and September. The fruits are 3 mm across.

Like most other broad-leaved pondweeds, Potamogeton lucens is tetraploid, with 2n=52.

Over much of its range, shining pondweed is not likely to be confused with any other species. However, in southern Europe the related and quite similar P. schweinfurthii has recently been discovered.P. lucens can usually be distinguished by its relatively broader leaves, 2-6 times as long as they are broad, and most or all of which are petiolate, but some forms are very difficult to distinguish without a detailed comparison of multiple characters.

However, there are hybrids with various other pondweed species including P. gramineus (P. × angustifolius J.Presl.), P. perfoliatus (P. × salicifolius Wolfg.), P. alpinus (P. × nerviger Wolfg.), P. nodosus (P. × subrufus Hagstr.) P. sarmaticus (P. × pseudosarmaticus Papch.), P. crispus (P. × cadburyae Dandy & G.Taylor), P. praelongus (P. × jutlandicus Zalewska-Gał.) and P. natans (P. × fluitans Roth). It hybridises with P. wrightii (P. × inbaensis Kadono)in Japan and China. Some of these hybrids can be quite common, and are not always easy to distinguish from P. lucens.

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Wikipedia