Lappula occidentalis var. occidentalis

Species category

Weed

Common name

flatspine stickseed, desert stickseed, western stickseed, flat-spine sheepburr

Diagnostic characters

Planting unit

NutletNutlet:
A small, dry, indehiscent carpel of a fruit, usually composed of one quarter of the fruit with each enclosing a single seed (e.g. mints).

Shape

SpatulateSpatulate:
Having a narrow base and rounded apex. Pear-shaped.

Size

  • Length 2–2.5 mm 
  • Width 1–1.5 mm 
  • Thickness 0.5–0.6 mm 

Color

Brown

Texture

TuberculateTuberculate:
Having small pimple-like protuberances.
with a crown of spines with recurved hooks on their ends on the dorsalDorsal:
Upper side or back of a seed or fruit.
side

Other structures

NutletNutlet:
A small, dry, indehiscent carpel of a fruit, usually composed of one quarter of the fruit with each enclosing a single seed (e.g. mints).
has a narrow scar on the ventralVentral:
Adaxial; of the side of an organ facing the axis (compare dorsal).
side and spines that follow the dorsalDorsal:
Upper side or back of a seed or fruit.
margin of the nutletNutlet:
A small, dry, indehiscent carpel of a fruit, usually composed of one quarter of the fruit with each enclosing a single seed (e.g. mints).
.

Identification notes

The nutletsNutlet:
A small, dry, indehiscent carpel of a fruit, usually composed of one quarter of the fruit with each enclosing a single seed (e.g. mints).
of Lappula occidentalis var. occidentalis and those of L. squarrosa are very similar.

Noxious weed seed categories

Not listed

AOSA examination list

Not included

Nomenclature

Family

Boraginaceae

Valid name

Lappula occidentalis var. occidentalis (S. Watson) Greene

Synonyms

Lappula echinata Gilib. var. occidentalis (S. Watson) B. Boivin
Lappula redowskii auct. non (Hornem.) Greene Lappula redowskii (Hornem.) Greene var. desertorum (Greene) I.M. Johnst.
Lappula redowskii (Hornem.) Greene var. occidentalis (S. Watson) Rydb.
Lappula redowskii (Hornem.) Greene var. redowskii 

 Lappula occidentalis  var.  occidentalis.  Nutlets with a loop of spines that follow the dorsal margin. 
Lappula occidentalis var. occidentalis. Nutlets with a loop of spines that follow the dorsal margin.