ClipArt ETC
Submerged leaves opposite; leaflets not toothed.

Cabomba

Submerged leaves opposite; leaflets not toothed.

Submerged leaves whorled; leaflets minutely toothed on one edge.

Ceratophyllum

Submerged leaves whorled; leaflets minutely toothed on one edge.

Leaves without midribs evident when examined against transmitted light; flowers yellow.

Heteranthera

Leaves without midribs evident when examined against transmitted light; flowers yellow.

Leaves with midribs evident when examined against light; flowers inconspicuous, not yellow.

Potamogeton

Leaves with midribs evident when examined against light; flowers inconspicuous, not yellow.

Leaf, when examined with hand lends, showing a central dense and a peripheral less dense zone.

Vallisneria

Leaf, when examined with hand lends, showing a central dense and a peripheral less dense zone.

Leaf, when examined with hand lends, not showing zones.

Alismaceae

Leaf, when examined with hand lends, not showing zones.

Leaves all from a hardened base or from a single point; base of leaves with spore sacs.

Isoetes

Leaves all from a hardened base or from a single point; base of leaves with spore sacs.

"Battle of Antietam, Burnside's Division, left wing- brilliant and decisive bayonet charge of Hawkins's Zouaves on the Confederate battery on the hill, right bank of Antietam Creek, near Sharpsburg, September 17th, 1862, utter route of the Confederates. This brilliant and decisive charge was made about five o'clock in the afternoon of Wednesday, September 17th. Our correspondent thus described the charge: 'On the left, during the afternoon, Burnside carried the bridge after an obstinate contest of several hours duration, and a loss of about five hundred killed and wounded. Hawkins's Zouaves then crossed and found the enemy ready drawn up under cover of the hills, and advanced in line of battle on the enemy's new position, about a half a mile distant. The ground over which they advanced was open clover and plowed fields, the latter very difficult and fatiguing to march in, owing to the softness of the ground. The enemy's guns, fourteen in number, kept up a terrible fire on our advancing line, which never wavered, but slowly toiled along, receiving shelter, however, when they were in the hollows. They were halted a few moments to rest in the hollow nearest the enemy's position, and then were ordered to charge with a yell. As they came up the hill in front of the enemy's batteries, they received a heavy volley from a large force of infantry behind a stone wall, about two hundred feet in front of the enemy's batteries. Our men, though terribly decimated, gave a volley in return, and then went on with the bayonet. The enemy did not stay to contest the ground, and, although two to one, broke and ran, leaving their guns.'"— Frank Leslie, 1896

Battle of Antietam

"Battle of Antietam, Burnside's Division, left wing- brilliant and decisive bayonet charge of Hawkins's…

"Battle of Antietam, Burnside's Division, left wing- brilliant and decisive bayonet charge of Hawkins's Zouaves on the Confederate battery on the hill, right bank of Antietam Creek, near Sharpsburg, September 17th, 1862, utter route of the Confederates. This brilliant and decisive charge was made about five o'clock in the afternoon of Wednesday, September 17th. Our correspondent thus described the charge: 'On the left, during the afternoon, Burnside carried the bridge after an obstinate contest of several hours duration, and a loss of about five hundred killed and wounded. Hawkins's Zouaves then crossed and found the enemy ready drawn up under cover of the hills, and advanced in line of battle on the enemy's new position, about a half a mile distant. The ground over which they advanced was open clover and plowed fields, the latter very difficult and fatiguing to march in, owing to the softness of the ground. The enemy's guns, fourteen in number, kept up a terrible fire on our advancing line, which never wavered, but slowly toiled along, receiving shelter, however, when they were in the hollows. They were halted a few moments to rest in the hollow nearest the enemy's position, and then were ordered to charge with a yell. As they came up the hill in front of the enemy's batteries, they received a heavy volley from a large force of infantry behind a stone wall, about two hundred feet in front of the enemy's batteries. Our men, though terribly decimated, gave a volley in return, and then went on with the bayonet. The enemy did not stay to contest the ground, and, although two to one, broke and ran, leaving their guns.'"— Frank Leslie, 1896

Battle of Antietam

"Battle of Antietam, Burnside's Division, left wing- brilliant and decisive bayonet charge of Hawkins's…

"With an ubrupt termination"-Whitney, 1902

Pinnate Leaf

"With an ubrupt termination"-Whitney, 1902

Upper leaves shorter and broader.

Callitriche

Upper leaves shorter and broader.

Plants stuff; rooting along the stem; leaves stiff and often fascicles.

Juncus

Plants stuff; rooting along the stem; leaves stiff and often fascicles.

Leaves with dilated bases.

Najas

Leaves with dilated bases.

Leaves with narrow bases.

Zannichellia

Leaves with narrow bases.

Selerolepis

Selerolepis

Selerolepis

Leaves usually three in whorls (sometimes four); flowers minute and inconspicuous

Anacharis

Leaves usually three in whorls (sometimes four); flowers minute and inconspicuous

Leaves crowded on stem; flowers three petaled, pink and fairly conspicuous.

Mayaca

Leaves crowded on stem; flowers three petaled, pink and fairly conspicuous.

Leaf-base apparently inflated.

Ruppia

Leaf-base apparently inflated.

Leaf-base narrow, sometimes with stipules.

Potamogeton

Leaf-base narrow, sometimes with stipules.

Leaves elliptic, the petiole ad under surface coated with a thick jelly-like material.

Brasenia

Leaves elliptic, the petiole ad under surface coated with a thick jelly-like material.

Leaves small, about 8 cm. in diameter or less; toothed or lobed.

Hydrocotyle

Leaves small, about 8 cm. in diameter or less; toothed or lobed.

Leaves small, mostly less than 15cm. long, heart-shaped; flowers white and less than 2.5cm across.

Nymphoides

Leaves small, mostly less than 15cm. long, heart-shaped; flowers white and less than 2.5cm across.

Flowers white; leaf-blade round.

Nymphaea

Flowers white; leaf-blade round.

Leaves round, often peltate; the long petiole attached near center of leaf.

Hydrocotyle

Leaves round, often peltate; the long petiole attached near center of leaf.

Plants aromatic when crushed; flowers blue.

Hydrotrida

Plants aromatic when crushed; flowers blue.

Stem finely pubescent, flowers 3-4 mm long.

Herpestris

Stem finely pubescent, flowers 3-4 mm long.

Stem not finely pubescent; flowers not more than 1.5mm long.

Micranthemum

Stem not finely pubescent; flowers not more than 1.5mm long.

flowers solitary in the axils of the leaves; leaves less than 3.5cm long.

Ludwigia

flowers solitary in the axils of the leaves; leaves less than 3.5cm long.

Flowers in stalked head-like spikes; leaves over 3.5cm long.

Alternanthera

Flowers in stalked head-like spikes; leaves over 3.5cm long.

Stems with a sheath just above attachment point of leaf; flowers individually small, white to pink.

Polygonum

Stems with a sheath just above attachment point of leaf; flowers individually small, white to pink.

Flowers large, showy yellow; fruit a four angled capsule.

Jussiaea

Flowers large, showy yellow; fruit a four angled capsule.

No leaf-sheaths present; flower cluster consisting of one to several showy, irregular, yellow, or purple blossoms.

Utricularia

No leaf-sheaths present; flower cluster consisting of one to several showy, irregular, yellow, or purple…

Leaf-sheaths present only at the base of stem; flowers in one group.

Eleocharis

Leaf-sheaths present only at the base of stem; flowers in one group.

Leaf-sheaths scattered along stem; flowers in several groups.

Fuirena

Leaf-sheaths scattered along stem; flowers in several groups.

Flwers or fruits hidden by overlapping scales.

Scirpus

Flwers or fruits hidden by overlapping scales.

Flowers or fruits individually manifest; parts in threes.

Juncus

Flowers or fruits individually manifest; parts in threes.

Sheaths at base of stem with edges united to form tube.

Eleocharis

Sheaths at base of stem with edges united to form tube.

Sheaths at base of stem merely overlapping.

Juncus

Sheaths at base of stem merely overlapping.

Plants small, mostly under 1 dm tall; leaves filiform, or very narrowly linear.

Myosurus

Plants small, mostly under 1 dm tall; leaves filiform, or very narrowly linear.

Plants aromatic when crushed.

Acorus

Plants aromatic when crushed.

Flowers violet, over 3cm scross; leaves equitant at base; that is coming in two ranks, making the base of the plant appear flattened.

Nemastylis

Flowers violet, over 3cm scross; leaves equitant at base; that is coming in two ranks, making the base…

Flowers inconspicuous and hidden by overlapping scales.

Cyperus

Flowers inconspicuous and hidden by overlapping scales.

Leaves large (1cm wide or wider); flowers very showy.

Iris

Leaves large (1cm wide or wider); flowers very showy.

Leaves smaller, rigid; small yellow flowers gathered in dense heads at top of naked stalk, each subtended by a scale-like bract.

Xyris

Leaves smaller, rigid; small yellow flowers gathered in dense heads at top of naked stalk, each subtended…

Leave from base of scrape bearing button like whitish heads of minute flowers; roots with cross-constrctions.

Eriocaulon

Leave from base of scrape bearing button like whitish heads of minute flowers; roots with cross-constrctions.

Leaves from base of scape bearing evident white flowers in racemes; roots without crss-constrictions.

Sagittaria

Leaves from base of scape bearing evident white flowers in racemes; roots without crss-constrictions.

Flowers with filaments connected by a funnel-like membrane.

Hymenocallis

Flowers with filaments connected by a funnel-like membrane.

Flowers with free filaments.

Crinum

Flowers with free filaments.

Leaf with a ligule at base (junction of leaf and sheath).

Graminae

Leaf with a ligule at base (junction of leaf and sheath).

Leaves narrow, mostly less than 1 cm.

Juncus

Leaves narrow, mostly less than 1 cm.

Sheaths abruptly contracted to blade of leaf; leaves without keels.

Typha

Sheaths abruptly contracted to blade of leaf; leaves without keels.

Sheaths narrowed to blade; leaves with keels.

Sparganium

Sheaths narrowed to blade; leaves with keels.

Flowers few, showy, pinkish purple.

Coreopsis

Flowers few, showy, pinkish purple.

Fruit flattened laterally; fruit not winged.

Ptilimnium

Fruit flattened laterally; fruit not winged.

Fruit flattened dorsally; fruit prominently winged.

Oxypolis

Fruit flattened dorsally; fruit prominently winged.

Root red.

Gyrotheca

Root red.

flowers white in dense button-like heads; leaves bristly-margined.

Eryngium

flowers white in dense button-like heads; leaves bristly-margined.

Flowers yellow, not in button-like heads nor with bristly-margined leaves.

Polygala

Flowers yellow, not in button-like heads nor with bristly-margined leaves.

Spores borne in sacs on lower leaf surface; divisions of the leaf small, less than 2 cm long.

Anchistea

Spores borne in sacs on lower leaf surface; divisions of the leaf small, less than 2 cm long.

Spores borne on terminal modified leaves; divisions of the leaf larger, more than 2 cm long.

Osmunda

Spores borne on terminal modified leaves; divisions of the leaf larger, more than 2 cm long.