Galium virgatum Nutt., wand bedstraw, southwest bedstraw. Annual, taprooted, (1—)several–stemmed at base, principal shoots erect to ascending, to 28 cm tall; shoots with only cauline leaves, generally not scabrous.
Stems 4–sided and 4–angled, square in ×–section, to 0.7 mm diameter, never woody, internodes to 20 mm long, short–bristly along colorless angles but lacking hooks, glabrous.
Leaves whorled, 4 per whorl, simple and sessile, without obvious stipules; stipules 2, indistinguishable from leaves (treated here as leaves); blade elliptic to oblong, 2—8 × 0.8—2 mm, short–ciliate on margins, acute at tip, 1–veined with vein obscure on upper surface and raised on lower surface, lower surface with milky, raised, blisterlike structures ca. 0.25 mm.
Inflorescence flowers 1—2 per node, later a condensed leafy cyme, subsessile on a dwarf shoot having a short stem and 2 bractlets; bractlet subtending subsessile flower leaflike, ovate, 2.5—3.5 × 1 mm, with milky, raised, blisterlike structures on lower surface.
Flower bisexual, radial, < 1 mm across; perianth (corolla) 4–lobed, of 1 whorl, cymbal–shaped (rotate), greenish white; tube short; lobes spreading, deltate to triangular, 0.5—0.6 × 0.3—0.4 mm, inconspicuously veined; stamens 4, fused to corolla tube; filaments erect, 0.2 mm long, white; anthers dorsifixed, dithecal, ca. 0.1 mm long, light whitish, longitudinally dehiscent; pollen white; nectary disc inconspicuous on top of ovary; pistil 1; ovary inferior, conspicuously 2–lobed, 0.5 mm long, covered by hooked bristles, 2–chambered, each chamber with 1 ovule; styles 2 (fused) erect, ca. 0.45 mm long, 2–branched, branches ascending, pale green; stigmas exserted at level of anthers, capitate, pale green.
Fruit schizocarp, reflexed, 2–chambered forming 2 dry, 1–seeded nutlets (mericarps) with fruit wall ± fused to seed coat; mericarp body subspheroid with flat side (1 mericarp aborted) or hemi–ellipsoid, 1.3—1.9 mm across, brown to dark brown, densely covered with hooked prickles ± 0.8 mm long, lacking hairs; sometimes the late–maturing mericarp dispersed with attached bractlet.
A. C. Gibson