Tetracoccus

Engelmann ex Parry

W. Amer. Sci. 1: 13. 1885.

Common names: Four-pod spurge
Etymology: Greek tetra, four, and kokkos, kernel or berry, alluding to 4-lobed capsule in T. dioicus
Synonyms: Halliophytum I. M. Johnston
Treatment appears in FNA Volume 12. Treatment on page 326.
 TaxonIllustrator 
FNA12 P39 Tetracoccus dioicus.jpegTetracoccus hallii
Bischofia javanica
Tetracoccus dioicus
Barbara Alongi

Shrubs, usually dioecious, sparingly hairy to glabrescent, hairs simple. Leaves often clustered on axillary short-shoots; blade glabrescent. Inflorescences: staminate paniclelike or racemelike thyrses, or fascicles on short-shoots; pistillate fascicles on short-shoots or flowers solitary. Pedicels present or absent. Staminate flowers: sepals 4–10, sometimes weakly differentiated in 2 whorls; nectary intrastaminal, lobed; stamens 4–10. Pistillate flowers: sepals 5–13, sometimes differentiated in 2 whorls; nectary lobed. Fruits capsules. Seeds oblong, ovoid, or pyriform, with one flattened radial surface if 2 seeds develop per locule, otherwise both radial surfaces rounded, seed-coat dry, smooth or wrinkled near hilum. x = 12.

Distribution

sw United States, n Mexico

Discussion

Species 5 (3 in the flora).

In addition to the three species treated for the flora area, Tetracoccus includes two Mexican species, T. capensis (I. M. Johnston) Croizat from the extreme tip of Baja California Sur and T. fasciculatus (S. Watson) Croizat from the Chihuahuan Desert.

Key

1 Leaves alternate and clustered on short shoots, blades 2–12 mm; staminate flowers in fascicles on short shoots; filaments glabrous; pistillate pedicels 1–3 mm; pistils usually 3-carpellate; seeds 1(–2) per locule, both radial surfaces usually rounded. Tetracoccus hallii
1 Leaves whorled, opposite, or subopposite, not clustered on short shoots, blades 15–30 mm; staminate flowers in paniclelike or racemelike thyrses; filaments villous basally; pistillate pedicels 6–15 mm; pistils usually 4-carpellate; seeds (1–)2 per locule, usually with one flattened radial surface. > 2
2 Leaf blades ovate to broadly elliptic, margins prominently serrate-dentate; staminate inflorescences congested paniclelike thyrses; pistillate sepals 8, in 2 series, greenish. Tetracoccus ilicifolius
2 Leaf blades oblong or oblanceolate to linear, margins entire or remotely serrulate; staminate inflorescences sparingly branched racemelike thyrses; pistillate sepals 7–13, in 1 series, red. Tetracoccus dioicus
... more about "Tetracoccus"
W. John Hayden +
Engelmann ex Parry +
pinnate +, serrate +, dentate +  and entire +
glabrescent +
Four-pod spurge +
sw United States +  and n Mexico +
Greek tetra, four, and kokkos, kernel or berry, alluding to 4-lobed capsule in T. dioicus +
pistillate +  and staminate +
racemelike +, paniclelike +  and staminate +
whorled +, opposite +  and alternate +
intrastaminal +
(2-)3-4(-5)-carpellate +
W. Amer. Sci. +
dressler1954a +
wrinkled +  and smooth +
1 +  and 2 +
pyriform +, ovoid +  and oblong +
distinct +
differentiated +
free +  and distinct +
distinct +
rounded +  and flattened +
Halliophytum +
Tetracoccus +
Picrodendraceae +
sparingly hairy;glabrescent +