Xanthocephalum gymnospermoides

(A. Gray) Bentham & Hooker f.

Gen. Pl.2: 249. 1873

Common names: San Pedro matchweed
Synonyms: Grindelia gymnospermoides
Basionyms: Gutierrezia gymnospermoides
Found in FNA Volume 20. Treatment on page 437.
FNA20 P46 Grindelia arizonica.jpeg
Plants 30–150 cm, herbage glabrous. Stems usually 1, erect. Leaf blades 40–100 mm, bases narrowly decurrent, margins entire to spinulose-toothed, faces resinous. Heads usually in tight to loose, corymbiform arrays, rarely borne singly. Peduncles: ultimate 1–40 mm, minutely stipitate-glandular. Phyllaries minutely stipitate-glandular. Ray corollas 4–11 mm. Pappi (ray) 0, outer disc 0 or minute crowns, inner nearly 0 or minute crowns, sometimes lacerate or with awnlike scales 0.2–0.8 mm, rarely with ring of persistent, 15–20, antrorsely ciliolate bristles ca. 1.4 mm. 2n = 12.

Phenology: Flowering (Jul–)Aug–Oct.
Habitat: Meadows, stream bottoms, ditches, grasslands, areas of oak-pine or pine woodlands, usually in habitats at least intermittently wet
Elevation: 1100–2700 m

Distribution

Ariz., Tex., Mexico (Chihuahua, Durango, Jalisco, Sonora, Zacatecas).

Discussion

References

None.

AuthorGuy L. Nesom +
BasionymGutierrezia gymnospermoides +
Common nameSan Pedro matchweed +
Elevation1100–2700 m +
HabitatMeadows, stream bottoms, ditches, grasslands, areas of oak-pine or pine woodlands, usually in habitats at least intermittently wet +
IllustratorBarbara Alongi +
PhenologyFlowering (Jul–)Aug–Oct. +
ReferenceNone +
SynonymGrindelia gymnospermoides +
Taxon nameXanthocephalum gymnospermoides +
Taxon parentXanthocephalum +
Taxon rankspecies +
VolumeVolume 20 +