4. Froelichia drummondii Moquin-Tandon in A. P. de Candolle and A. L. P. P. de Candolle, Prodr. 13(2): 421. 1849.
Froelichia floridana (Nuttall) Moquin-Tandon var. drummondii (Moquin-Tandon) Uline & W. L. Bray
Plants annual; taproot semi-woody. Stems 1-several, erect or ascending, sometimes procum-bent, simple or sparsely branched from base or above, stout, to 12 dm, puberulent or tomentulose with short, viscid, grayish hairs. Leaves principally on proximal 1/3 of stem, petiolate; blade broadly lanceolate to orbiculate, largest leaves 6.2-12(-16.5) × 1.3-3.8 cm, base attenuate to cuneate, apex obtuse to acute, canescent to subscabrous adaxially, sparsely sericeous-tomentose abaxially. Spikes dense, much-branched, apex often pyramidal, flowers arranged in 5-ranked spiral; bracteoles dark stramineous or blackish, glabrous or sparsely pubescent distally. Flowers 3.5-5.4 mm; perianth lobes stramineous, oblong, apex acute; filament lobes slightly or not at all recurved distally, brownish (often observed as brown flower tips), apex blunt. Utricles flask-shaped, 4.2-5 × 2.5-5 mm, with irregularly dentate lateral wings, both surfaces of perianth with distinct spines or tubercles.
Flowering year-round, primarily late summer-fall. Open sand plains, edges of oak woods, roadsides; Tex.
Froelichia drummondii has generally included robust plants with typically obtuse leaf apices, here assigned to F. floridana, from southern Oklahoma through central and southern Texas, and perennial plants treated here as F. interrupta var. cordata. Due to this broader species circumscription, most specimens in American herbaria are not correctly assigned. My field and herbarium studies have indicated that an interpretation of this taxon as restricted to the plains of south Texas probably most closely follows the original circumscription by Moquin-Tandon, and thus it is provisionally recognized here at the species level.
Froelichia drummondii is intermediate between F. interrupta and F. floridana, and it is intermediate in the transition from perennial to annual species in the genus. Designation as a variety of F. floridana, as has been done by recent authors, could be supported, but the shorter and darker filament lobes unique to the perennial taxa, a tendency toward shorter flowers, and the restricted range strongly support its recognition as a separate species. Further taxonomic work may verify the distinctiveness and relationship of this taxon to the remainder of the genus, particularly to F. floridana.