Gaudinia fragilis
Fragile oat
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Family: Poaceae · Type: Grass · Not Native
Gaudinia fragilis (Fragile oat) is a non-native California grass in the Poaceae family, recognized by Extremely rare Mediterranean introduction known from only a single California collection.
Fragile oat is a naturalized annual found in southern North Coast Ranges of Sonoma County on grassy hilltops with thin, rocky soil at approximately 100 meters elevation. Flowering in June, this plant produces delicate spike-like inflorescences with pale translucent spikelets to 20 millimeters long. Growing erect or ascending to 35 centimeters tall with distinctively long-shaggy hairy stems and leaves, it forms a slender, fragile grass. Its leaves feature long-shaggy hairy blades with short, truncate ligules, while the plant's unique characteristic is its inflorescence axis that breaks apart at prominent joints. The spikelets contain 3 to 6 florets, each with an elegant twisted awn 4 to 15 millimeters long that emerges from above the lemma's midpoint.
Identification and appearance
Key characters: Extremely rare Mediterranean introduction known from only a single California collection
Habitat and range
Habitat: Grassy hilltop on thin, rocky soil
Elevation: +- 100 m.
Outside California: this collection the only one from western North America
Bloom period
Gaudinia fragilis blooms Jun.
How to tell it apart
vs Danthonia: Gaudinia has twisted, bent awns; Danthonia has flat, twisted awns that spread in different directions.; vs Brachypodium: Gaudinia has completely smooth stem joints; Brachypodium has hairy joints.; vs Elymus: Gaudinia lacks auricles where leaf meets stem; Elymus has small ear-like auricles.; vs Triticum: Gaudinia has twisted, bent awns; Triticum has straight awns or none.; vs Agropyron: Gaudinia lacks auricles at leaf base; Agropyron has prominent ear-like auricles.
Frequently asked questions
Is Gaudinia fragilis native to California?
No. Gaudinia fragilis is not native to California (recorded as not native).
When does Gaudinia fragilis bloom?
Gaudinia fragilis blooms Jun.
What plant family does Gaudinia fragilis belong to?
Gaudinia fragilis is in the Poaceae family, genus Gaudinia.
What habitat does Gaudinia fragilis grow in?
Gaudinia fragilis grows in Grassy hilltop on thin, rocky soil.
Related species
Other California species in the same genus, family, or bioregion.
Sources: Jepson eFlora · CalPhotos
Last updated 2026-10-07
Data from The California Species Project — 14,000+ California species with verified data from CNPS, CDFW, USFWS, Cal-IPC, and more.