Scientific Family
Polygonaceae
Synonyms
Acanthogonum rigidum
Other common names
spine herb
rigid spine flower
spiny Chorizanthe.
Plant type
Forbs and Subshrubs
Origin
Native
Lifecycle
Annual
Height
3/4 inch to 4 inches
Riparian
No
Erect hairy stems and leaves; basal rosette leaves are oval with narrowing at the stem attachment; stem leaves are mostly bract-like, some basal-like leaves also present; flowers spiny, hairy; plant persists as brown-blackened herbage long after death.
Loose mat of basal leaves; woolly stems; stem leaves opposite or in threes, hard, pointed with age; yellow to greenish flowers on erect stems; base (involucre) supporting the flowers 3-angled, 3-ribbed and 3-toothed; 2 spiny tipped bracts subtend flowers.
Habitat
Found on sandy or gravely soils on slopes, flats and desert scrub communities. Widespread on the Mojave and Sonoran deserts.
Plant Community
Desert Scrub
Low elevation
0
High elevation
2500
Flower Characteristics
Dense clusters of yellow to greenish spiny flowers with 1 to 2 lobes, hairy; 9 stamens; flower is enclosed by an whorl of 3-angled, 3-ribbed, 3-toothed, spine-tipped bracts (involucre); below the involucre are 2 additional bracts.
Flower color
Yellow to greenish
Flower shape
Regular
Tubular
Yes
First bloom month
March
Last bloom month
May
Flower clusters
Other
Leaf and Stem Characteristics
Erect hairy stems arise from a rosette of narrow somewhat oval basal leaves; stems are straight at the base becoming branched; stem leaves lance-like, opposite or in threes, woolly hairs underneath, 3/4 inch long and 1/8 inch wide; sharp spines at tip.
Leaf type
Simple
Leaf color
Green
Leaf shape
Narrow
Leaf margin
Smooth
Leaves clasp
No
Leaf hairs
Leaves & stems
Spines
Yes
Fruit and Seed Characteristics
Fruit is hard, 3-angled; oval, 1/16 inch long; pointed at top (beak); does not open at maturity along lines or pores.
Fruit type
Achene
Fruit color
Brown