Gulf Coast Barbara's Buttons - Marshallia angustifolia

 

While some taxonomists include this species with Marshallia graminifolia, others separate Marshallia angustifolia from it as a distinct species.  They are very similar, but there are distinct differences as described below per Weakley's Flora:

Lower stem leaves (and basal leaves) spreading, oblanceolate or spatulate, with rounded or obtuse apices, relatively thin in texture, the 2 lateral nerves (parallel to the midnerve) often obscure; caudex lacking fibrous remnants of the previous year's leaves; phyllaries thin, linear-subulate, abruptly narrowing to the next series; [e. GA southward and westward; disjunct in Eastern Highland Rim of TN]  Marshallia angustifolia

Lower stem leaves (and basal leaves) erect, narrowly lanceolate to linear-lanceolate, with attenuate or long-acuminate apices, relatively thick in texture, the 2-4 lateral nerves (parallel to the midnerve) prominent; caudex with fibrous remnants of the previous year's leaves (if not burned off); phyllaries thick, ovate-attenuate, gradually narrowing to the next series; [NC, SC, and extreme e. GA]  Marshallia graminifolia

These photos, taken by Floyd Griffith and used with permission show the lower stem leaves as spreading instead of erect.

While grassleaf Barbara's buttons is vouchered from much of central peninsular Florida, Gulf Coast Barbara's buttons is confined to the northern third of the state.  It also is reported from Georgia west to Louisiana along the southern Gulf Coast.  

Like its close relative, it is a perennial species most commonly found in open moist habitats such as pine savannas and seepage bogs.  It dies back to the ground in winter and reemerges in early spring.  As the above photos show, the leaves are simple with entire margins (no teeth) and they alternate along the stem.  A single stem arises from the basal leaves and reaches a mature height by summer of 1-2 feet.  

A single flower head is produced at the tip of this main stem.  Ray petals are absent and the disc flowers that form the head are pink and quite showy.  Like other asters, the flowers open from the outer perimeter and proceed to the interior over several weeks. Most flowering in Florida occurs during the summer months. The flowers attract a wide variety of pollinators.

Though all members of this genus share a great many qualities that would make them desirable in a moist setting in a home landscape, none are grown (to the best of my knowledge) by members of FANN - the Florida Association of Native Nurseries.  Hopefully, that will be corrected someday in the future.  I have never had ripe achenes to attempt it myself, but I suspect it would not be difficult from seed.