FNA: Portulaca amilis vs. Portulaca

Phenology

Flowering late spring–early fall.

Habitat

Fields, granitic outcrops, disturbed habitats

Elevation

0-200 m (0-700 ft)

Distribution

AL; FL; GA; NC; SC; South America [Introduced in North America]

[WildflowerSearch map]

[BONAP county map]

Nearly worldwide; primarily tropical and subtropical; also temperate

[BONAP county map]

Discussion

Prior to 1981, Portulaca amilis had been included conceptually within P. pilosa (A. E. Radford et al. 1968). However, W. S. Judd and R. P. Wunderlin (1981) correctly identified P. amilis as an introduction from South America. It tends to occur in the sandy soils at the junction of the coastal plain and the piedmont provinces, but it is also spreading north and south through the coastal plain, where it has exhibited a weedy nature, as shown by collection data from Virginia to Florida. Portulaca amilis has only pink to purple petals in the United States; C. D. Legrand (1962) reported a yellow form of the species in South America. A. F. Clewell (1985) incorrectly gave the petal color of P. amilis as yellow. J. F. Matthews and P. A. Levins (1985) traced the spread of the species in the southeast and theorized as to the means of introduction.

(Discussion copyrighted by Flora of North America; reprinted with permission.)

Species 100–125 (10 in the flora).

(Discussion copyrighted by Flora of North America; reprinted with permission.)

Key

Key Based on Flowering Material

1. Petals pink to purple	→ 2
1. Petals yellow, orange, copper, bronze, or white	→ 6
2. Flowers 25 mm or more diam.; petals 15 mm or longer	P. grandiflora
2. Flowers to 25 mm diam.; petals 12 mm or shorter	→ 3
3. Leaf blades flattened, 2-12 mm wide, obovate to spatulate or oblanceolate	P. amilis
3. Leaf blades terete to hemispheric, 0.5-3 mm wide, linear to lanceolate	→ 4
4. Petals deeply 2-lobed; stamens 40 or more; stem nodes with inconspicuous trichomes; restricted to sandstone outcrops in s Georgia	P. biloba
4. Petals not 2-lobed; stamens usually fewer than 30; stem nodes with conspicuous trichomes; widespread in United States	→ 5
5. Petals medium pink to almost white; seeds 0.6 mm or more diam., elongate; restricted to granitic outcrops in Georgia, North Carolina, South Carolina, Virginia	P. smallii
5. Petals dark pink to purple; seeds 0.6 mm or less diam., orbiculate; wide- spread throughout se, lower Midwest, and sw United States	P. pilosa
6. Flowers 25 mm or more diam	→ 7
6. Flowers 20 mm or less diam	→ 8
7. Plants perennial; roots tuberous; stems stiffly erect; sw United States	P. suffrutescens
7. Plants annual; roots fibrous; stems prostrate to suberect; widespread	P. grandiflora
8. Leaf blades terete to hemispheric, linear to lanceolate, usually 3 mm or less wide	→ 9
8. Leaf blades flattened, obovate or spatulate (sometimes lanceolate in P. umbraticola), 2-15 mm or more wide	→ 10
9. Stem nodes and inflorescences with conspicuous trichomes; flowers less than 8 mm diam.; Midwest and sw United States	P. halimoides
9. Stem nodes and inflorescences with inconspicuous trichomes; flowers more than 9 mm diam.; tropical Florida	P. rubricaulis
10. Capsules encircled by expanded, membranaceous wing	P. umbraticola
10. Capsules not winged	P. oleracea

Key Based on Fruiting Material

1. Capsules each encircled by expanded, membranaceous wing	P. umbraticola
1. Capsules not winged	→ 2
2. Leaf blades flattened	→ 3
2. Leaf blades terete to hemispheric	→ 4
3. Trichomes at stem nodes absent or inconspicuous; seeds 0.6-1.1 mm or more diam.	P. oleracea
3. Trichomes at stem nodes conspicuous; seeds 0.4- 0.6 mm or less diam	P. amilis
4. Stem nodes with inconspicuous trichomes	→ 5
4. Stem nodes with conspicuous trichomes	→ 6
5. Seeds 0.7 mm or more diam., surface cells distinctly stellate, tuberculate	P. biloba
5. Seeds less than 0.7 mm diam., surface cells obscurely stellate, without tubercles	P. rubricaulis
6. Seeds 0.6-1 mm diam	→ 7
6. Seeds 0.3-0.65 mm diam	→ 8
7. Longest leaves usually longer than 20 mm; capsules usually more than 4 mm diam	P. grandiflora
7. Longest leaves usually shorter than 15 mm; capsules 3.5 mm or less diam.	P. smallii
8. Capsules 2 mm or less diam.; lateral seed coat with densely arranged, flattened, stellate cells, tubercles absent; seeds averaging 0.5 mm or less diam.	P. halimoides
8. Capsules 1.5-5 mm diam.; seed coat with loosely arranged, stellate cells; tubercles usually present; seeds averaging more than 0.5 mm diam	→ 9
9. Plants annual; roots fibrous to slightly fleshy; stems prostrate or suberect to erect	P. pilosa
9. Plants perennial; roots tuberous; stems stiffly erect	P. suffrutescens