Alismataceae

Intermountain Flora, v. 6, p. 7

• 1. Achenes arranged in a single ring on the receptacle; stamens 6.
• 2. Achenes rounded on the back, not conspicuously beaked, the beak short and less than 1 mm long, the ring of achenes smooth; petals entire or only slightly erose. Alisma
• 2.1. Achenes centrally grooved at the tip, the style straight or nearly so, (0.4)-0.5-0.8 mm long; leaves lanceolate to oblong or broadly elliptic to ovate, mostly 2-20 cm wide; pedicels ascending or erect; petals 3.5-6 mm long, white; inflorescence surpassing the leaves. Alisma triviale = Alisma plantago-aquatica var. americanum

Alisma triviale	Alisma triviale	Alisma triviale	Alisma triviale

• 2.1' Achenes centrally ridged and with two grooves towards the tip, the style curled, 0.4-0.5 mm long; leaves linear to narrowly elliptic, mostly less than 3 cm wide; pedicels widely spreading and curved; petals 2-4 mm long, pinkish or whitish; inflorescence not always surpassing the leaves. Alisma gramineum

Alisma gramineum	Alisma gramineum	Alisma gramineum

• 2' Achenes conspicuously horned on the back with a sharp beak 3-6 mm long, the rung of achenes forming a stellate pattern; petals toothed. Damasonium californicum = Machaerocarpus californicus

Damasonium californicum	Damasonium californicum	Damasonium californicum	Damasonium californicum

• 1' Achenes densely packed over the entire surface of the receptacle; stamens more than 6.
• 3. Leaves rounded to truncate or subcordate at the base; flowers perfect; achenes arranged into a bur-like head; stems and petioles angled; known in our area only from Utah: Uintah county (Green River Bird Refuge). Echinodorus berteroi = Echinodorus rostratus

Echinodorus berteroi	Echinodorus berteroi	Echinodorus berteroi	Echinodorus berteroi

• 3' Leaves sagittate to hastate or infrequently tapered at the base, often ribbon-like when emersed; flowers perfect or all pistillate or all staminate; achenes usually arranged in a smooth head; stems and petioles smooth and terete; common. Sagittaria
• 3'1. Achenes with beaks extending at right angles to the body, the beak 0.5-1.5 mm long; plants sometimes diodecious; lobes of the leaves about equal length; bracts of the inflorescences 5-10-(15) mm long; rare; San Juan county?. Sagittaria latifolia

Sagittaria latifolia	Sagittaria latifolia	Sagittaria latifolia	Sagittaria latifolia

• 3'1' Achenes with beaks erect, the beak 0.2-0.4 mm long; plants monoecious; lobes of the leaves unequal, the terminal one longer than the two lateral lobes; bracts of the inflorescences (5)-10-30 mm long; common. Sagittaria cuneata

Sagittaria cuneata	Sagittaria cuneata	Sagittaria cuneata