Helianthella microcephala (Small Head Sunflower)
Asteraceae (Sunflower Family)

This was a difficult plant to identify, because the tight, small buds took weeks to open and then they only revealed purple disk flowers (as shown below).  Attempts to identify the plant as an Asteraceae with only disk flowers failed and it was only when the tiny (and few) yellow ray flowers opened that identification was possible.

When Helianthella microcephala finds suitable habitat it often grows in large numbers, as it does in Lone Mesa State Park and Hawkins Preserve.  Tight masses of basal leaves are followed by long few-leaved stems and very small flower heads ("microcephala").  In the photographs on this page, Helianthella microcephala is seen growing on Mancos Shale, where it thrives in large numbers.

A few weeks after the above photograph was taken, disk flowers opened on many plants but few plants had ray flowers.

Disk flowers open many days before the tiny yellow ray flowers appear.  Flower heads are only 1/4 to 1/2 inch high and wide and it is common to find many plants with only disk flowers.

Range map © John Kartesz,
Floristic Synthesis of North America

State Color Key

Species present in state and native
Species present in state and exotic
Species not present in state

County Color Key

Species present and not rare
Species present and rare
Species extirpated (historic)
Species extinct
Species noxious
Species exotic and present
Native species, but adventive in state
Eradicated
Questionable presence

Range map for Helianthella microcephala