4.
Iva axillaris
Pursh, Fl. Amer. Sept. 2: 743. 1813.
Iva axillaris
var.
robustior
Hooker
Perennials,
10—40(—60) cm (rhizomatous).
Stems
erect (usually herbaceous).
Leaves:
petioles 0—3 mm; blades narrowly ovate or obovate to elliptic or spatulate, 15—25(—45) × 3—8(—15) mm, margins rarely toothed, faces usually ± strigose to scabrellous, gland-dotted.
Heads
in ± racemiform arrays.
Peduncles
1—2 mm.
Involucres
± hemispheric, 2—3 mm.
Phyllaries:
outer 3—5 ± connate, ± herbaceous.
Paleae
linear, 1.5—2 mm.
Pistillate florets
3—5(—8); corollas 0.5—1.5 mm.
Functionally staminate florets
4—8(—20+); corollas 2—2.5 mm.
Cypselae
2.5—3 mm.
2
n
= 36, 54.
Flowering May—Oct. Seasonally wet, saline habitats; 10—2500 m; Alta., B.C., Man., Sask.; Ariz., Calif., Colo., Idaho, Kans., Minn., Mont., Nebr., Nev., N.Mex., N.Dak., Okla., Oreg., S.Dak., Tex., Utah., Wash., Wis., Wyo.
