Your are here:

Spiny emex

Scientific Name
Emex australis
Scientific Author
Steinheil, A.D. (1838)
(Magnoliophyta: Magnoliopsida: Polygonales: Polygonaceae)

Page menu options:

Diagnostic Images

Achene Dorsal
Seed Project
Clare McLellan Museum Victoria
Image Options
Diagnostic Images (5)
Diagnostic Notes
Pictured: Achene

Disseminule: Fruit (referred to as an achene or seed unit) pictured with persistent floral parts


Achene appendages: Spines, Cavities

Achene Colour: Variable - red/brown

Achene Length: 7 - 10mm

Achene Sculpture: Enclosed in persistent hardened perianth, Roughened, Spinate

Achene Shape: 3 - spined or triangular in cross section, depressions in lower portion form a tapered base.

Fruit an achene enclosed in persistent hardened perianth 4.5–11(12) mm long, 2.5–5.5 mm wide and thick (not including spines). Three sided, each side with 2 depressions in upper portion, and 2 depressions in lower portion; all the lower depressions together form a tapered base. Toward the apex, each edge (of outer segments) extends outward into a straight, rigid, sharp spine. Three bract-like inner segments form a connivent apex. Cross section slightly triangular to nearly round. Surface dull, light to dark straw-colored to brown; dusty appearance, smooth to rough. Scar cream-colored, irregular in shape, with 3–6 small holes. Embryo peripheral, cotyledons shorter than radicle; endosperm readily visible.

(Scher, J. L. and D. S. Walters. 2010. Federal noxious weed disseminules of the U.S. California Department of Food and Agriculture, and Center for Plant Health Science and Technology, USDA, APHIS, PPQ.)

Source: See Web Links Federal Noxious Weed Disseminules of the U.S.
More Information
Clare McLellan
19/09/2011 04:52 AEST
Last Updated
21/01/2013 11:46 AEST
Clare McLellan (2011) Spiny emex (Emex australis) Updated on 1/21/2013 11:46:53 AM Available online: PaDIL -
Image Use
Free for use under the Creative Commons Attribution 3.0 Australia License