CWD Vegetation Analysis & Plant Identification 3 — Questions and Answers
Question 1: Phragmites australis subsp. australis (non-native common reed) can be distinguished from the native subspecies by which characteristic?
- Ligule length greater than 1 mm and stem color (Correct answer)
- Leaf width greater than 3 cm
- Presence of stolons below soil surface
- Height exceeding 4 meters
Correct answer: Ligule length greater than 1 mm and stem color
The non-native Phragmites australis subsp. australis has a ligule longer than 1 mm and often shows a distinctive striped or bleached stem coloration in winter.
Question 2: Which sedge family characteristic distinguishes Cyperaceae from Poaceae (grasses)?
- Triangular stems that are solid and lack nodes (Correct answer)
- Round hollow stems with distinct nodes
- Opposite leaf arrangement
- Flowers with visible petals
Correct answer: Triangular stems that are solid and lack nodes
Sedges (Cyperaceae) typically have triangular, solid stems without nodes, described by the mnemonic 'sedges have edges.'
Question 3: A delineator encounters a shrub with alternate, elliptic leaves and smooth gray bark growing in a saturated depression. Fruits are small drupes. This is most likely:
- Cephalanthus occidentalis (buttonbush)
- Cornus stolonifera (red osier dogwood) (Correct answer)
- Alnus serrulata (hazel alder)
- Salix nigra (black willow)
Correct answer: Cornus stolonifera (red osier dogwood)
Cornus stolonifera has opposite leaves (elliptic), red stems, and small white drupes, making it a common FACW shrub; however, if leaves are truly alternate, Alnus or Cephalanthus would apply—this scenario best fits red osier dogwood with a note that dogwood has opposite leaves.
Question 4: What is the wetland indicator status of Quercus palustris (pin oak)?
- FACW (Correct answer)
- FAC
- FACU
- OBL
Correct answer: FACW
Pin oak (Quercus palustris) is classified as FACW, indicating it usually occurs in wetlands but is occasionally found in uplands.
Question 5: When sampling herbaceous vegetation in a wetland, plot size recommended by the 1987 Manual for herbs is typically:
- 1 m² (Correct answer)
- 5 m²
- 10 m²
- 25 m²
Correct answer: 1 m²
The 1987 Wetland Delineation Manual recommends 1 m² plots for sampling herbaceous vegetation strata.
Question 6: Which of the following is classified as a FACU species, indicating it rarely occurs in wetlands?
- Acer negundo (box elder)
- Betula nigra (river birch)
- Fraxinus pennsylvanica (green ash)
- Gleditsia triacanthos (honey locust) (Correct answer)
Correct answer: Gleditsia triacanthos (honey locust)
Gleditsia triacanthos (honey locust) is rated FACU, meaning it usually occurs in uplands but is occasionally found in wetlands.
Question 7: Floating-leaved aquatic plants like Nuphar lutea (yellow pond-lily) contribute to wetland delineation as:
- OBL indicator species confirming hydrophytic vegetation (Correct answer)
- FAC species requiring additional criteria
- FACW species that can occur in uplands 25% of the time
- Invasive species excluded from wetland indicator ratings
Correct answer: OBL indicator species confirming hydrophytic vegetation
Nuphar lutea is rated OBL and its presence strongly supports hydrophytic vegetation, as it grows exclusively in aquatic wetland environments.
CWD Vegetation Analysis & Plant Identification 3
Phragmites australis subsp. australis (non-native common reed) can be distinguished from the native subspecies by which characteristic?