The Genus Eschscholzia

California Poppies and Their Relatives

Dichotomous key to the species of Eschscholzia

This key is based on an early draft that I submitted for the key in The Jepson Manual: Higher Plants of California. It does not yet include species found exclusively outside California (E. elegans and E. palmeri)

    1. Plants perennial; receptacle generally with a prominent rim; cotyledons usually bifid
    E. californica ssp. californica

    1. Plants annual; receptacle rim present or absent; cotyledons simple or bifid

      2. Receptacle rim present

      2. Receptacle rim absent (cotyledons never bifid)

        4. Flowers scapose; terminal divisions of the leaves acute, longest commonly > 5 mm (often > 10mm); petals yellow, buds glabrous

          5. Buds erect; seeds bur-like by raised ridges; petals < 12 mm long; plants of GV, SNF
          E. lobbii

          5. Buds erect or more often nodding at least when young; seeds with microscopic pits, not bur-like; petals usually > 12mm long; plants of DMoj, DSon
          E. glyptosperma

        4. Flowers borne on leafy stems (not easily apparent in young plants); terminal divisions of the leaves acute or obtuse; petals yellow or orange; buds glabrous or pubescent

          6. Buds pubescent, always nodding; leaves pubescent

            7. Petals orange or deep yellow throughout, usually > 15 mm long; receptacles > 1.5 mm wide; plants of grasslands
            E. lemmonii

            7. Petals yellow, sometimes with an orange spot at the base, usually < 15 mm long; receptacles < 1.5 mm wide; plants of open areas in chaparral
            E. hypecoides

          6. Buds glabrous, nodding or erect; leaves glabrous or glaucous but never consistently pubescent

            8. Older buds nodding; plants of deserts

              9. Terminal lobes of the leaves slender, acute, > 1.5 mm long, foliage bright green or yellow-green; petals 8-30 mm long; seeds spherical
              E. parishii

              9. Terminal lobes of the leaves broadened at the tip, usually obtuse, < 2 mm long, foliage grayish or bluish green; petals 3-26 mm long; seeds oblong
              E. minutiflora

            8. Buds erect; plants of valleys, foothills, and canyons

              10. Receptacle somewhat swollen and translucent at top, usually > 2 mm wide

              10. Receptacle strictly conic, upper margin not translucent, < 2.5 mm wide

                12. Flower buds blunt or with a short, rounded tip < 1/4 the length of the bud; lower divisions of the leaves elongate, giving an open appearance; plants of ChI
                E. ramosa

                12. Flower buds long pointed, the tip usually exceeding 1/4 the length of the bud; lower divisions of the leaf short, giving a compact appearance; plants of the mainland foothills
                E. caespitosa