An emergent monocot growing along a waterway with round, hollow stems and highly branched, silky appearing seed heads is most likely which species?

• A. Common reed
• B. Water hyacinth
• C. Reed canarygrass
• D. Water smartweed

Answer: (A)

Identifying emergent aquatic grasses relies on stem shape and the appearance of the seed head. Round, hollow stems are a hallmark of true reeds, which tend to grow along watercourses with their bases in the mud and their stems rising above the surface. A highly branched, silky-looking seed head fits the feathery plume that common reed (Phragmites australis) produces, giving that soft, airy appearance.

Water hyacinth is a floating plant, not an emergent reed, and its inflorescence and growth form don’t match the tall, hollow-stemmed reed with a plume-like seed head. Reed canarygrass has tall stems and an open panicle, but its seed head is less feather-like and more branched in a denser, less silky way. Water smartweed shows pink flowers on slender spikes rather than a large, plumelike, silky seed head. So the combination of emergent habitat, round hollow stems, and a silky, highly branched seed head best points to common reed.