Aquatic Botany

Angiosperms

Hydrophytes

Plants growing in water or on a substrate that is at least periodically

deficient in oxygen as a result of excessive water content.

Categorizing Wetland Plants for Delineation Purposes

(p. 755 of Mitsch)

• Obligate Wetland (OBL)-occur almost always (>99%) in wetlands; E.g., Typha latifolia, Cattail

• Facultative Wetland (FACW)-occur usually (67-99%) in wetlands, but also occur in non-wetlands (1-33%); E.g., Onoclea sensibilis, Sensitive Fern

• Facultative (FAC)-similar likelihood of occurring in wetlands and non-wetlands (33-67%); E.g., Euthamia graminifolia, Grass-leaved Goldenrod

• Facultative Upland (FACU)-occur sometimes in wetlands (1-33%) but more often in non wetlands; E.g., Quercus rubra, Red Oak

• Obligate Upland (UPL)-occur rarely (<1%) in wetlands; e.g., Dennsteadtia punctilobula, Hay-scented Fern

(+/- may be appended)

Categorizing Wetland Plants by Growth Form

• Emergent-with leaves that extend above the water surface; e.g., Northern Blue Flag, Iris versicolor

• Free-floating-float freely on the water surface; e.g., Duckweed, Lemna minor

• Floating-leaved-leaves float on water surface; e.g., Spatterdock, Nuphar variegata

• Submersed-most of leaves growing under water surface; e.g., Curly-leaf Pondweed, Potomogeton crispus

Emergents

Blue Flag Iris Cattail, Typha sp.

Emergents

• tolerate fluctuating water levels• may dampen shoreline wave erosion;

stabilize sediments with interlocking rootbed of rhizomes

• usually with protective waxy cuticle• leaves with aerenchymous tissue making

them buoyant, useful for waterfowl nests• may reproduce aerially (flowers) or

vegetatively by rhizomes

Aerenchyma

American Burreed, Sparganium americanum

Purple Loosestrife

Floating-leaved Plants

Water Meal, Wolfia sp. Giant Duckweed, Spirodelia

Floating-Leaved Plant Community

• cirucular/eliptical leaves with smooth margins resist tearing

• leathery; thick cuticle (waterproofing)• stomata on surface• aerenchyma• often long petioles; often covered with mucilage• may reproduce from flowers or by extensive

rhizomes• free-floating plants produce turions to overwinter

Spatterdock

Fragrant White Water Lily, Nymphea

Submersed Plant Community

• leaves flexible, often finely divided; provide structure for invertebrates

• no cuticle; often limp-the water provides support

• heterophylly is common

• stems photosynthesize

• some reproduce from seed, others by turion, rhizomes, or tuber

Submersed Plants

Naiad, Najas sp.

Elodea canadensis

Pondweeds, Potomogeton sp.

Carex

Bristly Sedge, C. comosa Tussock Sedge, Carex stricta

Juncus

Soft Rush, Juncus effusus