Key to Sparganium

View taxon page for Sparganium

(For a list of species in Sparganium, use the above link.)

Jepson Manual glossary definitions can be seen by moving your cursor over words underlined with dots.

1. Inflorescence main axis branches (0)1–4; staminate heads ± 10–60; stigmas > 1 on 5–100% of pistillate flowers; fruit body (except beak) ± 

truncate 

Abruptly (not gradually) narrower or smaller at base or tip, as if cut straight across or nearly so.

to hemispheric distally; plants ± terrestrial or emergent, not aquatic, 

erect 

Upright; vertically oriented.

..... S. eurycarpum

2. Stigmas 2(3–4) on ± (40)60–100% of pistillate flowers; fruit body except beak 8–9 mm, 5–7 mm wide, distally ± truncate to low-rounded ..... var. eurycarpum

2' Stigmas 2 on ± 5–40% of pistillate flowers; fruit body except beak 5–8 mm, 3–6 mm wide, distally rounded to generally 

tapered 

Gradually (not abruptly) narrower or smaller at base or tip.

..... var. greenei

1' Inflorescence main axis branches 0; staminate heads <= 10; stigma 1; fruit body (except beak) distally tapered or rounded; plants terrestrial to aquatic, erect to limp

3. Staminate heads 1–2; stigma 0.3–0.8 mm; fruit beak 0.5–1.5 mm; plants generally aquatic, limp ..... S. natans

3' Staminate heads 3–7; stigma (0.6)0.8–2(2.5) mm; fruit beak >= 1.5 mm; plants terrestrial to emergent, aquatic, limp or not

4. Leaf blades ± flat, or convex, or generally some obscurely 3-angled or keeled, widest 1–5 mm wide; fruit beak 1.5–2.2 mm; staminate heads 3–4(5), crowded in flower; plants generally aquatic, limp, distal parts floating ..... S. angustifolium

4' Leaf blades generally 3-angled or keeled, especially proximally, generally obscure in pressed specimens, widest 5–13 mm wide; fruit beak (2)3–4(5) mm; staminate heads 3–7, well-separated to crowded in flower; plants generally terrestrial to emergent, erect, or aquatic and limp with distal parts floating ..... S. emersum

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