BOTN 201 - Department of Biology - TAMU


Caryophyllales: Phytolaccaceae - The Pokeweed Family


A family of 18 genera and ca. 125 species that are mostly herbs with alternate, simple, entire leaves. The most familiar North American taxon is Phytolacca americana (Pokeweed). This species, fairly representative of the family, shows a structural feature - incomplete fusion of the carpels - that has influenced many to place the Phytolaccaceae as a basal element of the Caryophyllales.


Inflorescence of P. americana

Note racemose pattern of development with flowers at the tip and fruits forming at the inflorescence base. Leaves are simple, alternate, and entire.

Fruit of Phytolacca americana

Syncarpy is not complete in that stylar portion of each carpel is separate at the top of each compound pistil

Fruit x-section of P. americana

This xection shows 10 carpels with a single seed in each locule

Floral structure of P. americana is typical of the family in that it shows a single whorl of perianth parts (sepals), 10 stamens, and a partially syncarpous gynoeciuim

P. americana flower at anthesis. Note uniseriate perianth, hypogyny (androperianth attached BELOW the gynoecium, and separate sylar extensions from each carpel.

P. americana flower past anthesis. Note withering perianth and expanding gynoecium with each carpel forming a 'lobe' of the ovary.


Notes:


Diagnostic characters:


Economic importance:

Emerging shoots and young leaves of P. americana, a perennial herb, are often harvested as spring greens or 'poke salad'. Older tissue of this species is TOXIC, although root tissue said to have medicinal uses at the proper dosage.


  • Last updated by HDW on 24 January 1995