Glaucous herbs, with yellow sap, spiny-toothed leaves and large showy flowers. Sepals 2 or 3. Petals 4-6. Stamens ∞. Placentae 4-6, many-ovuled. Style very short or none. Stigma dilated, 3-6-radiate. Capsule prickly, oblong, dehiscent at the apex by valves. Seeds numerous, cancellate. [Greek, an eye disease, supposed to be relieved by the plant so called.]

A genus of about 10 species, natives of America. Type species: Argemone mexicana L.

Petals yellow, or rarely cream-colored; flowers nearly or quite sessile.


A. mexicana.

Petals white, or pinkish.

Flowers distinctly peduncled; spines of the sepal-tips nearly erect.


A. alba.

Flowers sessile or nearly so; spines of the sepal-tips spreading.


A. intermedia.

1. Argemone Mexicana L. Mexican Prickly Or Thorn Poppy

Fig. 1978

Argemone mexicana L. Sp. Pl. 508. 1753.

Stem stout, 1°-2° high, simple or sparingly branched, spiny or sometimes nearly unarmed. Leaves sessile, clasping by a narrowed base, 4'-10' long, 2'-4' wide, glaucous, white-spotted, runcinate-pinnatifid, spiny-toothed and more or less spiny on the veins; flowers yellow or cream-colored, sessile or subsessile, 1'-2' broad; sepals acuminate, bristly-pointed; stamens 4"-5" long; filaments slender, much longer than their anthers; stigma sessile or nearly so; capsule I' long or more.

In waste places, Massachusetts to New Jersey, Pennsylvania, Florida and Texas. Also in ballast about the northern seaports. Adventive from tropical America. A common weed in the American tropics, and introduced into the Old World. The seed yields a valuable painter's oil. June-Sept. Bird-in-the-bush. Devil's-fig. Yellow, Flowering or Jamaica thistle.

1 Argemone Mexicana L Mexican Prickly Or Thorn Pop 3201 Argemone Mexicana L Mexican Prickly Or Thorn Pop 321

2. Argemone ┴lba Lestib. White Prickly Poppy

Fig. 1979

Argemone alba Lestib. Bot. Belg. Ed. 2:3: Part 2, 132. 1799.

A. albiflora Hornem. Hort. Havn. 469. 1815.

Commonly stouter and taller than the preceding species. Leaves pinnatifid or pinnately lobed, glaucous or green, not blotched, but sometimes whitish along the veins; flowers white, usually much larger, 3'-4' broad, distinctly peduncled; petals rounded; spines of the sepal-tips stouter; capsules i'-1 1/2' long.

Georgia and Florida to Missouri and Texas. Spontaneous after cultivation in northern gardens. May-Aug.

3. Argemone Intermedia Sweet. Leafy White Prickly Poppy

Fig. 1980

Argemone intermedia Sweet, Hort. Brit. Ed. 2, 585. 1830. Stem stout, prickly, glabrous and glaucous, often 2o high or more. Leaves lobed or pinnatifid, very prickly, usually whitish-blotched; flowers large, white, sessile or nearly so, 3'-4' wide; petals rounded; spines of the sepal-tips spreading; capsule oblong, prickly, about 1' long.

Prairies and plains, Illinois to South Dakota, Wyoming, Nebraska, Texas and Mexico. Has been confused with the preceding species, and with A. platyceras Link & Otto. May-Aug.

Argemone hispida A. Gray, ranging from Wyoming to Utah and New Mexico, differs in the stem and branches being hispid-pubescent. It has been recorded from Kansas, perhaps erroneously.

3 Argemone Intermedia Sweet Leafy White Prickly Po 322