SANTALACEAE, the Sandalwood Family

Low herbs with alternate entire leaves and terminal clusters of small greenish-white bell-shape flowers without petals in spring and early summer.

1a. Inflorescence of several-flowered clusters terminating the stem and in the upper axils Toad-flax, Comandra umbellata.
1b. Inflorescence of axillary clusters of 1-5 flowers Toad-flax, Comandra livida.


LORANTHACEAE, the Mistletoe Family

Parasitic plants, attached to the branches of trees.

One species in Michigan, a dwarf brown plant 5-20 mm. long, with minute scale-like leaves, growing on the branches of Black Spruce Dwarf Mistletoe, Arceuthobium pusillum.


ARISTOLOCHIACEAE, the Birthwort Family

Flowers greenish-brown or reddish-brown, at or near the ground, with inferior 6-celled ovary.

1a. Leaves alternate, on the stem; flowers on a basal scaly branch (1-4 dm. high; summer) Virginia Snakeroot, Aristolochia serpentaria.
1b. Leaves a single basal pair, bearing 1 short-stalked flower between them (spring)
(Wild Ginger) — 2.
2a. Lobes of the perianth ending in a tubular portion 5-8 mm. long Wild Ginger, Asarum canadense.
2b. Lobes of the perianth ending in a tubular portion over 1 cm. long Wild Ginger, Asarum canadense var. acuminatum.
2c. Lobes of the perianth triangular, not tubular at the end Wild Ginger, Asarum canadense var. reflexum.


POLYGONACEAE, the Buckwheat Family

Herbs with alternate entire leaves, stipules surrounding the stem above the base of each leaf, and small green, white or pink flowers without petals.

1a. Erect or ascending or prostrate or floating plants — 2.
1b. Scrambling or climbing plants, clinging by sharp recurved prickles on the 4-angled stems (flowers greenish or pink, summer) (Tear-thumb) — 32.
1c. Twining vines (flowers white or greenish, summer) — 33.
2a. Sepals 6, the 3 inner ones enlarging in fruit and surrounding the achenes; flowers in panicles — 3.
2b. Sepals 4 or 5 (occasional flowers may be found with 6 sepals, but the flowers are not in panicles) (summer) — 13.
3a. Leaves arrow-shape or halberd-shape, with 2 basal lobes (Sorrel) — 4.
3b. Leaves without basal lobes (Dock) — 5.
4a. Leaves halberd-shape, the basal lobes directed sidewise Red Sorrel, Rumex acetosella.
4b. Leaves arrow-shape, the basal lobes directed backward Green Sorrel, Rumex acetosa.
5a. The projecting wings of the fruiting calyx (known as valves) with sharp slender teeth Bitter Dock, Rumex obtusifolius.
5b. Valves entire or finely dentate, but without sharp slender teeth — 6.
6a. Pedicels straight, thickened toward the end, all regularly deflexed, 3-4 times longer than the fruiting calyx Swamp Dock, Rumex verticillatus.
6b. Pedicels slender, flexuous, spreading — 7.
7a. Leaves flat or nearly so — 8.
7b. Leaves with strongly crisped or wavy-curled margins; plants usually of cultivated grounds or waste places (5-10 dm., summer) — 12.
8a. With grain-like tubercles on all 3 valves of the fruit — 9.
8b. With grain-like tubercles on only one valve, or entirely lacking — 10.
9a. Valves broadly cordate, finely toothed Water Dock, Rumex brittanica.
9b. Valves triangular-ovate, entire or nearly so Dock, Rumex mexicanus.
10a. Valves oblong Bloody Dock, Rumex sanguineus.
10b. Valves broadly heart-shape — 11.
11a. Grain-like tubercle less than half as long as the valve Patience Dock, Rumex patientia.
11b. Grain-like tubercle more than half as long as the valve Tall Dock, Rumex altissimus.
12a. The grain-like tubercle on the valves of the fruit broadly ellipsoid, with rounded apex Sour Dock, Rumex crispus.
12b. Tubercle ovoid with tapering apex Sour Dock, Rumex elongatus.
13a. Flowers inconspicuous, in small axillary clusters; leaves jointed at the base (Knotweed) — 14.
13b. Flowers more or less conspicuous, in obvious spikes or racemes which terminate the stems or branches, or arise from the axils of the upper leaves — 18.
14a. Leaves sharply folded lengthwise (1-4 dm. tall) Knotweed, Polygonum tenue.
14b. Leaves flat or nearly so — 15.
15a. The small sepals pink or white at the margin (stems prostrate or ascending) — 16.
15b. Sepals greenish or yellowish throughout (stems erect or ascending) — 17.
16a. Leaves thin; common weed of dooryards and gardens Knotweed, Polygonum aviculare.
16b. Leaves thick and fleshy; a plant of sandy shores Knotweed, Polygonum aviculare var. littorale.
17a. Leaves narrowly lanceolate or linear-oblong; rare species Knotweed, Polygonum ramosissimum.
17b. Leaves broadly oblong, oval, or elliptical; common weed of yards and gardens Knotweed, Polygonum erectum.
18a. Leaves broadly triangular (3-7 dm. high; flowers white) Buckwheat, Fagopyrum esculentum.
18b. Leaves from linear to ovate or oblong — 19.
19a. Sepals 4; flowers in very long and slender spike-like racemes (4-10 dm. high) Knotweed, Polygonum virginianum.
19b. Sepals 5; flowers in spikes or racemes — 20.
20a. Flowers on slender pedicels, forming a loose raceme; leaves linear, jointed at the base (1-3 dm. high; flowers pink or white; chiefly near the Great Lakes) Jointweed, Polygonella articulata.
20b. Flowers sessile or nearly so, forming a spike or spike-like raceme — 21.
21a. Stipular sheaths at the base of the leaves ciliate at their upper margin — 22.
21b. Stipular sheaths not ciliate at the upper margin — 28.
22a. Sheaths with spreading borders — 23.
22b. Sheaths without a spreading border, appressed to the stem (Smartweed) — 24.
23a. Leaves ovate, acuminate; stem erect (1-2 m. high; flowers pink) Prince's Feather, Polygonum orientate.
23b. Leaves oblong, obtuse or subacute; spreading or ascending plant of wet soil Water Smartweed, Polygonum amphibium var. hartwrightii.
24a. Peduncles with glandular hairs (5-15 dm. high) Smartweed, Polygonum careyi.
24b. Peduncles not glandular (1-8 dm. high) (Smartweed) — 25.
25a. Sepals beset with minute black dots — 26.
25b. Sepals white, pink, or red, not black-dotted — 27.
26a. Racemes drooping or nodding at the tip; achene dull-colored Smartweed, Polygonum hydropiper.
26b. Racemes erect; achene smooth and shining Smartweed, Polygonum acre.
27a. Sheaths smooth; leaves usually with a dark spot near the base Smartweed, Polygonum persicaria.
27b. Sheaths hairy; leaves not dark-spotted Smartweed, Polygonum hydropiperoides.
28a. Leaves obtuse or somewhat acute at the apex — 29.
28b. Leaves acuminate at the apex (5-15 dm. high; flowers white to pink) (Smartweed) — 30.
29a. Stem unbranched, erect, bearing a single terminal raceme (5-30 cm. high; flowers pink) Bistort, Polygonum viviparum.
29b. Stem branched, submerged in water or creeping on muddy shores (flowers pink) Water Smartweed, Polygonum amphibium.
30a. Raceme single or two; leaves broadly ovate-lanceolate, about 3 times as long as wide Smartweed, Polygonum muhlenbergii.
30b. Racemes numerous; leaves lanceolate, 4-6 times as long as wide — 31.
31a. Racemes drooping or nodding at the tip Smartweed, Polygonum lapathifolium.
31b. Racemes erect Smartweed, Polygonum pennsylvanicum.
32a. Leaves arrow-shape, the basal lobes pointing backward Tear-thumb, Polygonum sagittatum.
32b. Leaves halberd-shape, the basal lobes pointing sidewise Tear-thumb, Polygonum arifolium.
33a. The three outer sepals becoming conspicuously winged in fruit (False Buckwheat) — 34.
33b. The sepals all unchanged in fruit, except in size (Black Bindweed) — 35.
34a. Wings of the fruit with wavy-curled margins False Buckwheat, Polygonum scandens.
34b. Wings of the fruit flat False Buckwheat, Polygonum dumetorum.
35a. Leaf-sheaths with a ring of bristles at the base Black Bindweed, Polygonum cilinode.
35b. Leaf-sheaths without a ring of bristles Black Bindweed, Polygonum convolvulus.


CHENOPODIACEAE, the Goosefoot Family

Herbs, with inconspicuous greenish or reddish flowers without petals, in summer.

1a. Leaves linear or nearly so, entire — 2.
1b. Leaves of a broader shape, usually toothed or lobed — 5.
2a. Leaves rather stiff, narrowly linear or thread-like, with spine-like tips Russian Thistle, Salsola kali var. tenuifolia.
2b. Leaves soft, not spine-like — 3.
3a. Widely branched, rather diffuse, 1-5 dm. tall; plant of the shore of the Great Lakes Bug-seed, Corispermum hyssopifolium.
3b. Erect plants with ascending branches — 4.
4a. Leaves glabrous (3-6 dm. tall) Goosefoot, Chenopodium leptophyllum.
4b. Leaves minutely ciliate on the margin (bushy branched, 5-10 dm. tall) Kochia, Kochia scoparia.
5a. Principal leaves with a broad truncate, rounded, or hastate base — 6.  
5b. Principal leaves narrowed to the base — 12.
6a. Leaves broadly ovate, with 1-4 large sharp projecting teeth on each side Goosefoot, Chenopodium hybridum.
6b. Leaves hastate or triangular-ovate, entire or with many teeth — 7.
7a. Leaves entire or merely undulate — 8.
7b. Leaves sharply or sinuately toothed — 9.
8a. Stem erect, simple or sparingly branched Good King Henry, Chenopodium bonus-henricus.
8b. Stem diffuse or ascending, freely branched Orache, Atriplex patula.
9a. Flowers in small heads, in the axils or in terminal spikes; leaves sinuately toothed or nearly entire Strawberry Blite, Chenopodium capitatum.
9b. Flowers in terminal panicles; leaves sharply toothed (Goosefoot) — 10.
10a. Panicles short, not as long as the subtending leaves Goosefoot, Chenopodium murale.
10b. Panicles long, exceeding the subtending leaves — 11.
11a. Calyx green Goosefoot, Chenopodium urbicum.
11b. Calyx red Goosefoot, Chenopodium rubrum.
12a. Foliage glandular and strongly aromatic — 13.
12b. Foliage not glandular nor aromatic; sometimes ill-scented — 15.
13a. Flowers in large loose open spreading panicles; leaves deeply pinnatifid Jerusalem Oak, Chenopodium botrys.
13b. Flowers clustered in slender axillary or terminal spikes — 14.
14a. Spikes dense, leafy Mexican Tea, Chenopodium ambrosioides.
14b. Spikes open, nearly leafless Wormseed, Chenopodium ambrosioides var. anthelminticum.
15a. Stem erect, 5-20 dm. tall; leaves frequently white-mealy Lamb's Quarters, Chenopodium album.
15b. Stem prostrate or ascending, succulent; leaves glaucous-white beneath Goosefoot, Chenopodium glaucum.
15c. Stem widely and diffusely branched; leaves green, soon deciduous Cycloloma, Cycloloma atriplicifolium.


AMARANTHACEAE, the Amaranth Family

Herbs, with alternate leaves, and inconspicuous greenish or reddish flowers without petals, which are axillary or in dense clusters, blooming in summer.

1a. Flower-clusters axillary — 2.
1b. Flower-clusters in terminal spikes or panicles, sometimes also axillary — 3.
2a. Plant prostrate or decumbent; seed about 1.5 mm. broad Pigweed, Amaranthus blitoides.
2b. Plant erect or ascending, widely branched; seeds about 1 mm. broad (3-10 dm. high) Tumble Weed, Amaranthus graecizans.
3a. Principal leaves with a pair of spines at their base Thorny Amaranth, Amaranthus spinosus.
3b. Spines none at the base of the leaves — 4.
4a. Weedy plants of cultivated or waste ground; flowers monoecious or polygamous; pistillate flowers with a calyx (Pigweed) — 5.
4b. Plants of swamps or stream-banks; flowers dioecious; pistillate flowers without calyx (Water Hemp) — 7.
5a. Spikes short, 1-8 cm. long, crowded in dense ovoid panicles; the terminal spike not conspicuously elongated beyond the appressed or ascending lower ones Pigweed, Amaranthus retroflexus.
5b. Spikes slender, 1-12 cm. long; the terminal spike greatly exceeding the short inconspicuous divergent lower ones — 6.
6a. Bracts subulate, sharply awned Pigweed, Amaranthus hybridus.
6b. Bracts merely acuminate Pigweed, Amaranthus paniculatus.
7a. Flowers in leafy spikes, or the lower in separate clusters Water Hemp, Acnida tuberculata.
7b. Flowers in separate distinct clusters Water Hemp, Acnida tuberculata var. subnuda.


PHYTOLACCACEAE, the Pokeweed Family

Herbs with alternate entire leaves, small flowers without petals, and a many-celled ovary.

One species in Michigan, 1-2 m. high, with numerous racemes of whitish flowers, in late summer, followed by dark-purple berries Pokeweed, Phytolacca decandra.


NYCTAGINACEAE, the Four-o'Clock Family

Herbs, with opposite entire leaves and flowers in small clusters surrounded by a broad open calyx-like involucre; the true calyx colored like a corolla; petals none (4-8 dm. high; flowers purple, in summer).

1a. Leaves lanceolate or narrower, sessile Umbrella-wort, Oxybaphus hirsutus.
1b. Leaves ovate, petioled Umbrella-wort, Oxybaphus nyctagineus.


ILLECEBRACEAE, the Knotwort Family

Herbs, with opposite entire leaves, and minute flowers without petals. (Prostrate spreading or freely branched plants, 3 dm. high or less; flowers in summer.)

1a. Stipules none; leaves slightly connate at base, subulate Knawel, Scleranthus annuus.
1b. Stipules present, but small; leaves elliptical or oval (Forked Chickweed) — 2.
2a. Stems pubescent; internodes seldom more than 1 cm. long Forked Chickweed, Anychia polygonoides.
2b. Stems smooth; internodes about 2 cm. long Forked Chickweed, Anychia canadensis.


AIZOACEAE, the Carpet-weed Family

Prostrate herbs, with whorled leaves and small whitish axillary flowers without petals, in summer.

One species in Michigan Carpet-weed, Mollugo verticillata.


CARYOPHYLLACEAE, the Pink Family

Herbs, with opposite or whorled entire leaves, and stems frequently swollen at the nodes. Sepals 4 or 5; petals separate, as many as the sepals, or rarely none; stamens twice as many as the petals in plants with conspicuous flowers, sometimes fewer in those with small flowers; ovary 1-celled, with the ovules on a central axis, and with 2-5 styles.

1a. Calyx spreading, of separate sepals; flowers 15 mm. wide or less; petals sometimes none — 2.
1b. Calyx tubular, of united sepals; flowers in many species more than 15 mm. wide; petals always present — 22.
2a. Stipules present — 3.
2b. Stipules none — 4.
3a. Leaves opposite; flowers pink (about 1 dm. high; summer) Sand Spurrey, Spergularia rubra.
3b. Leaves whorled; flowers white (1-5 dm. high; leaves linear; summer) Spurrey, Spergula arvensis.
4a. Leaves subulate or thread-like — 5.
4b. Leaves linear to ovate — 7.
5a. Leaves opposite (1 dm. high or less; flowers white, summer) Pearlwort, Sagina procumbens.
5b. Leaves fascicled in the axils — 6.
6a. Styles 4 or 5 (1 dm. high; terminal white flowers 5 mm. wide, in summer) Pearlwort, Sagina nodosa.
6b. Styles 3 (1-4 dm. high; flowers white, nearly 1 cm. wide, summer) Stitchwort, Arenaria stricta.
7a. Petals entire (3 dm. high or less; flowers white, in summer) (Stitchwort) — 8.
7b. Petals notched or 2-cleft at the end, or none — 11.
8a. Principal leaves 1 cm. long or less — 9.
8b. Principal leaves 1.5 cm. long or more — 10.
9a. Petals half as long as the sepals Stitchwort, Arenaria leptoclados.
9b. Petals almost as long as the sepals Stitchwort, Arenaria serpyllifolia.
10a. Leaves oblong-oval, obtuse. Stitchwort, Arenaria lateriflora.
10b. Leaves lanceolate, acute. Stitchwort, Arenaria macrophylla.
11a. Capsule splitting by valves at maturity; styles usually 3 (Chickweed) — 12.
11b. Capsule opening by terminal teeth at maturity; styles usually 5 (tufted or matted plants, 1-5 dm. high; flowers white, in spring and summer) (Mouse-ear Chickweed) — 18.
12a. Petals distinctly shorter than the sepals, or none — 13.
12b. Petals as long as the sepals, or longer — 15.
13a. Leaves ovate (1-3 dm. high; flowers white, all summer) Chickweed, Stellaria media.
13b. Leaves lanceolate to oblong (in water or wet places, 1-4 dm. high; flowers white, in summer) — 14.
14a. Flowers in a leafy terminal branching cluster Chickweed, Stellaria borealis.
14b. Flowers in a lateral cluster with minute bracts Chickweed, Stellaria uliginosa.
15a. Flowers in clusters with leaf-like bracts, or axillary and solitary (in water or wet places; 1-3 dm. high; flowers white, summer) Chickweed, Stellaria crassifolia.
15b. Flowers in clusters with scale-like bracts — 16.
16a. Leaves distinctly linear; cymes lateral; a common species in marshes (2-5 dm. high; flowers white, early summer) Chickweed, Stellaria longifolia.
16b. Leaves distinctly broadest near the base; flower-cluster terminal — 17.
17a. Pedicels erect; clusters usually few-flowered; in extreme northern part of the state only (1-3 dm. high; flowers white, summer) Chickweed, Stellaria longipes.
17b. Pedicels spreading; clusters open, many-flowered (2-6 dm. high; flowers white, in summer) Chickweed, Stellaria graminea.
18a. Petals distinctly longer than the sepals — 19.
18b. Petals as long as the sepals, or shorter than them — 21.
19a. Flowers much less than 1 cm. wide Mouse-ear Chickweed, Cerastium nutans.
19b. Flowers more than 1 cm. wide — 20.
20a. Stem-leaves linear or narrowly lanceolate Mouse-ear Chickweed, Cerastium arvense.
20b. Stem-leaves oblong Mouse-ear Chickweed, Cerastium arvense var. oblongifolium.
21a. Bracts green; pedicels short and inflorescence crowded Mouse-ear Chickweed, Cerastium viscosum.
21b. Bracts with transparent white margins; pedicels longer than the calyx and inflorescence open Mouse-ear Chickweed, Cerastium vulgatum.
22a. Styles 5 — 23.
22b. Styles 3 (3-10 dm. high; flowers in summer) — 25.
22c. Styles 2 — 29.
23a. Calyx-teeth much longer than the calyx-tube (erect, 4-10 dm. high; flowers large, red, late summer) Corn Cockle, Agrostemma githago.
23b. Calyx-teeth shorter than the calyx-tube (4-10 dm. high; flowers in summer) — 24.
24a. Flowers crimson Mullein Pink, Lychnis coronaria.
24b. Flowers white or pink White Campion, Lychnis alba.
25a. Flowers night-blooming, always wilted during the day Catchfly, Silene noctiflora.
25b. Flowers open during the day — 26.
26a. Flowers 6 mm. wide or less, white or pink Catchfly, Silene antirrhina.
26b. Flowers 1-2 cm. wide, white to pink or purple — 27.
26c. Flowers 2 cm. wide or more, crimson Fire Pink, Silene virginica.
27a. Principal leaves in whorls of 4 Starry Campion, Silene stellata.
27b. Leaves opposite — 28.
28a. Calyx globular, much inflated or bladder-like Bladder Campion, Silene latifolia.
28b. Calyx club-shape, not inflated Sweet William Catchfly, Silene armeria.
29a. Leaves linear or narrowly lanceolate, 5 mm. wide or less (flowers pink or white, in summer) — 30.
29b. Leaves lanceolate or ovate (flowers pink, white, or red, in summer) — 32.
30a. Flowers in terminal clusters; leaves hairy (2-4 dm. high) Deptford Pink, Dianthus armeria.
30b. Flowers solitary at the ends of long pedicels — 31.
31a. Flowers 3-4 mm. wide (1-2 dm. high) Gypsophyll, Gypsophila muralis.
31b. Flowers 1 cm. wide or more (1-5 dm. high) Meadow Pink, Dianthus deltoides.
32a. Flowers less than 1 cm. broad — 33.
32b. Flowers more than 1 cm. broad — 34.
33a. Flowers white, in large panicles (4-7 dm. high) Baby's Breath, Gypsophila paniculata.
33b. Flowers pale red, in loose clusters (4-10 dm. high) Cowherb, Saponaria vaccaria.
34a. Leaves with 3-5 prominent veins (4-7 dm. high) Soapwort, Saponaria officinalis.
34b. Leaves with one mid-vein (3-6 dm. high) Sweet William, Dianthus barbatus.


PORTULACACEAE, the Purslane Family

Herbs with opposite or alternate leaves and regular flowers with 2 sepals, 5 petals, and a 1-celled ovary with 2 or 3 styles.

1a. Leaves a single pair on each stem (1-2 dm. high; flowers pink, in racemes in early spring) (Spring Beauty) — 2.
1b. Leaves numerous (prostrate or spreading; flowers in summer) — 3.
2a. Leaves lance-ovate to oblong, not more than six times as long as wide Spring Beauty, Claytonia caroliniana.
2b. Leaves linear or linear-lanceolate, more than six times as long as wide Spring Beauty, Claytonia virginica.
3a. Flowers yellow, about 5 mm. wide Purslane, Portulaca oleracea.
3b. Flowers 2-5 cm. wide Portulaca, Portulaca grandiflora.


CERATOPHYLLACEAE, the Hornwort Family

Submerged aquatics, with whorled, finely dissected leaves and inconspicuous flowers with neither calyx nor corolla.

One species in Michigan Hornwort, Ceratophyllum demersum.


NYMPHAEACEAE, the Water Lily Family

Aquatic plants, with usually large and floating leaves which are round or elliptical and palmately veined.

1a. Floating and emersed leaves centrally peltate — 2.
1b. Leaves rounded but not peltate, with a deep sinus — 3.
2a. Leaves round, 3 dm. in diameter or more; flowers very large, pale yellow Lotus, Nelumbo lutea.
2b. Leaves oval, 5-15 cm. long; flowers small, purple Water Shield, Brasenia schreberi.
3a. Flowers yellow (Pond Lily) — 4.
3b. Flowers white or tinged with pink (Water Lily) — 5.
4a. Leaves more than 1 dm. long Pond Lily, Nymphaea advena.
4b. Leaves less than 1 dm. long Pond Lily, Nymphaea microphylla.
5a. Flowers very fragrant; leaves purplish beneath Water Lily, Castalia odorata.
5b. Flowers not fragrant; leaves green beneath Water Lily, Castalia tuberosa.