All Floras      Advanced Search
FNA Vol. 4 Page 457, 458, 496 Login | eFloras Home | Help
FNA | Family List | FNA Vol. 4 | Portulacaceae

7. Portulaca Linnaeus, Sp. Pl. 1: 445. 1753; Gen. Pl. ed. 5, 204. 1754.

Purslane [Latin portula, little door, in reference to the lid of the capsule]

James F. Matthews

Portulaca oleracea

Credit: Harvard University Herbaria

Herbs, annual (perennial in P. suffrutescens). Roots tuberous, fleshy, fibrous, or small taproots. Stems erect to prostrate, branched, fleshy or suffrutescent; trichomes in inflorescence or stem nodes absent or present, glabrous otherwise. Leaves alternate or subopposite, congested and involucrelike immediately proximal to inflorescence; blade terete, subterete, or flattened. Inflorescences terminal in clusters, or axillary on short branches. Flowers sessile or subsessile, usually open only in sunshine; sepals broadly clasping at base, herbaceous to scarious, falling from top of capsule; petals ephemeral, 5-7, usually distinct, margins usually entire; stamens (4-)6-40(-100); ovary half inferior to inferior, plurilocular proximally to 1-locular distally, placentation free-central; style 1, short, stigmas 3-8(-18). Capsules membranaceous, chartaceous, dehiscence circumscissile. Seeds many, brown to black or gray, reniform to cochleate; seed coat smooth or variously sculptured, granular to stellate-tuberculate or spiny. x = 4, 5, 8, 9.

Species 100-125 (10 in the flora): nearly worldwide, primarily tropical and subtropical, also temperate.


Legrand, C. D. 1962. Las especies Americanas de Portulaca. Anales Mus. Hist. Nat. Montevideo, ser. 2, 7: 1-147. Matthews, J. F. and P. A. Levins. 1985. The genus Portulaca in the southeastern United States. Castanea 50: 96-104. Walters, S. M. 1964. Portulaca. In: T. G. Tutin et al., eds. 1964-1980. Flora Europaea. 5 vols. Cambridge. Vol. 1, p. 114. Wilson, P. 1932b. Portulaca. In: N. L. Britton et al., eds. 1905+. North American Flora.... 47+ vols. New York. Vol. 21, pp 328-336.

Key Based on Flowering Material

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

List of Keys

  • List of lower taxa


    Related Objects  

    Flora of Chile  
  • PDF
  • PDF
    Flora of China  
  • PDF File
  • PDF

  •  |  eFlora Home |  People Search  |  Help  |  ActKey  |  Hu Cards  |  Glossary  |