Cyperaceae The Sedge Family Juncaceae The Rush Family PBIO 369, Fall 2015

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)

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

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

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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.

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

Dulichium arundinaceum, Three-way sedge

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

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

Eriophorum, cotton grass: Perianth of long bristles

Cyperaceae: The Sedge Family 90 genera, 4000 species worldwide

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

Carex: perigynium

A Key to Vermont Cyperaceae

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

Cyperus: florets are distichous

If perfect and distichous, it is either Cyperus or Dulichium

Spirally imbricate

Spirally imbricate Tubercle?

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

Tubercle minute Tubercle broad Bulbostylis Rhynchospora

No tubercle Conspicuous bristles?

Yes, bristles Very long: Eriophorum Shorter: Scirpus

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

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

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

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