Pondweed

Species: Potamogeton nodosus Poir. Date: 2006-09-24 Location: Small dam in forest off the Woodland Rd, Vumba Habitat: In the water; spikes emergent

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Potamogeton americanus, spray showing attachment of cases of caddis fly (fam. Leptoceridae).

Potamogeton obtusifolius, winter buds. October.

Potamogeton Robbinsii, photo-micrograph of section through old stem, showing arrangement of mechanical tissue.

Potamogeton heterophylius. 12, typical habit of land form; 13, terminal portion of rootstock showing tendency to become tuberous; 14, same, more advanced stage; 15, aquarium specimen

Leafy pondweed (Potamogeton foliosus). Niagra Falls to Michigan and California (After Britton & Brown)

Species: Potamogeton nodosus Poir. Date: 2006-09-24 Location: Small dam in forest off the Woodland Rd, Vumba Habitat: In the water; spikes emergent

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Potamogeton americanus. 1, seed; 2, seedling 5 days old; 3, seedling 14 days old; 4, seedling of four months; A, winter buds; 5, germinating winter bud, natural size; the last two winter buds belated in development. Aquarium specimen, January 24, 1914

Potamogeton obtusifolius, erect axes bearing winter buds. October.

Potamogeton Robbinsii, photo-micrograph of section through old stem, showing arrangement of mechanical tissue--Detail.

Potamogeton heterophyllus (16-17); Potamogeton perfoliatus (18-19). 16, aquarium specimen; 17, aquarium specimen; 18, winter shoot showing elongation of internodes; 19, growing tips of same

Potamogeton amplifolius, leaves, showing characteristic mines of Hydrellia.

Species: Potamogeton nodosus Poir. Date: 2006-09-24 Location: Small dam in forest off the Woodland Rd, Vumba Habitat: In the water; spikes emergent

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Potamogeton americanus. 1, seed; 2, seedling 5 days old; 3, seedling 14 days old; 4, seedling of four months; A, winter buds; 5, germinating winter bud, natural size; the last two winter buds belated in development. Aquarium specimen, January 24, 1914; 6, rootstock with winter bud A, natural size. September

Potamogeton Robbinsii, branch, showing points where dismemberment occurs.

Potamogeton heterophyllus.

Potamogeton amplifolius (7) rootstock; Potamogeton heterophyllus (8); Potamogeton heterophyllus (9-12). 7, rootstock; 8, submerged plant; 9, rootstock not tuberous; 10, tuberous rootstock; 11, tuberous rootstock

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Long-leaved pondweed (Potamogeton lonchites). Found in ponds and slow streams, New Brunswick to Washington, south to Florida and California (After Britton & Brown)

Curled-leaved Pondweed (Potamogeton crispus). Found in fresh, brackish or even salt water, Massachusetts to Pennsylvania and Virginia. Also in Europe (After Britton & Brown)

Potamogeton amplifolius, rooted tip of branch, a propagative structure.