1. Cyperaceae The Sedge Family Juncaceae The Rush Family
PBIO 369, Fall 2010

2. Character
JUNCACEAE (Rushes)
CYPERACEAE (Sedges)
POACEAE (Grasses)
Habitat
Mostly wet areas
Wetlands and upland woods
Various
Stems
Terete in cross section
Internodes solid with large pith
Nodes not jointed
Triangular (not always visible)
Internodes usually solid
Terete or ellipsoid
Internodes hollow (to solid)
Nodes jointed
Leaves
3-ranked
Blades flat to terete
Open sheath
Blades flat
Closed sheath
2-ranked
Inflorescence
Basically cymose and often congested
Each flower subtended by 2 bracts
Spikelets
Each flower subtended by one bract (scale)
Each flower subtended by 2 bracts (lemma and palea
Perianth
Usually 6 chaffy tepals
Absent or reduced to a number of bristles or scales
Reduced to 2 (or 3) scales
Fruit
Loculicidal capsule
Achene
Caryopsis (grain)

3. Juncaceae The Rush Family
Vegetative attributes:
Annual or perennial herbs
Stems often round in section
Leaves flat or round in section
Leaves mostly basal

5. Juncaceae The Rush Family
Reproductive attributes:
Perianth of six papery tepals
Androecium of [three] six stamens
Ovary superior, three fused carpels
Three brush-like stigmas
Fruit a capsule

8. Juncaceae The Rush Family
Two genera in Vermont
Juncus – rush (leaves mostly round in section). Mostly wet areas. Twenty-two species.
Luzula – wood rush (leaves flat, hairy). Upland woods. Six species.

10. Cyperaceae The Sedge Family
Vegetative attributes:
Mostly perennial herbs
Stems often three-angled
Nodes not swollen
Internodes not hollow
Leaves three-ranked, sheaths not split

11. Dulichium arundinaceum, Three-way sedge

12. Cyperaceae The Sedge Family
Reproductive attributes:
Perianth, if present, of bristles or scales
Androecium of three stamens
Ovary superior, 2-3 fused carpels
Fruit an achene
Each floret subtended by a scale
Florets arranges in spikelets

13. S Staminate florets Scale Spikelet Pistillate florets
Carex: no perianth, flowers unisexual

14. Eriophorum, cotton grass:
Perianth of long bristles

15. Cyperaceae: The Sedge Family 90 genera, 4000 species worldwide

16. Vermont Genera: Carex (sedge) – 125 species
Scirpus (bulrush) – 17 species
Cyperus (umbrella sedge, galingale) – 10 species
Eleocharis (spike rush) – 9 species
Dulichium (three-way sedge) – 1 species, common
Eriophorum (cotton grass) – 5 species
Rhynchospora (beak rush) – 4 species
Cladium (twig rush) – 1 species, uncommon
Fimbristylis (autumn fimbristylis) – 1 species, rare
Bulbostylis (sand sedge) – 1 species

17. Carex: perigynium

19. A Key to Vermont Cyperaceae

20. Perigynium?
Yes: Carex No
Flowers
perfect
and
distichous
Flowers
spirally
imbricate

21. Distichous

22. If perfect and distichous, it is either
Cyperus or
Dulichium

23. Spirally imbricate

24. Spirally imbricate
Tubercle?

25. Yes, tubercle
Spikelet one per culm
Spikelets more than one per culm
Eleocharis

26. Tubercle minute
Tubercle broad
Bulbostylis
Rhynchospora

27. No tubercle
Conspicuous bristles?

28. Yes, bristles
Very long:
Eriophorum
Shorter:
Scirpus

29. Bract of inflorecence one:
No conspicuous bristles
Bract of inflorecence one:
Scirpus

30. Bracts of inflorecence multiple Flowers one per spikelet:
No conspicuous bristles
Bracts of inflorecence multiple
Flowers one per spikelet:
Cladium

31. Flowers several per spikelet
No conspicuous bristles, bracts of inflorescence multiple
Flowers several per spikelet
Leaves > 5 mm wide:
Scirpus

32. Leaves narrower
Leaf sheaths long-ciliate
Leaf sheaths short-ciliate
Bulbostylis
Fimbristylis