Jepson Flora Project: Jepson Interchange    

The Jepson Manual: Higher Plants of California

  • Up-to-date information about California vascular plants is available from the Jepson eFlora.

Names are linked to treatments from the Manual


N.B.: couplets are linked, e.g., 1. is linked to 1'.

  1. Plant generally aquatic, stem generally submersed or floating (sometimes stranded); petals white, white and yellow, or yellow
    2. Most leaves floating or emergent, simple, entire
R. hydrocharoides
    2' Most or all leaves submersed, generally 2–6-dissected (if floating or emergent, leaves, if any, sometimes simple, 3-lobed)
      3. Floating or emergent leaves generally 0 or like submersed, 3–6-dissected, segments thread-like, entire
R. aquatilis
        4. Petiole below generally flat, wide, above generally thread-like; leaf generally = or < internode; pedicel ± straight in fruit; fruits 10–30
R. aquatilis var. capillaceus
        4' Petiole generally flat, wide ± throughout; leaf generally << internode; pedicel recurved in fruit; fruits 10–50
R. aquatilis var. subrigidus
      3' Floating or emergent leaves generally 0 or unlike submersed, ± 3-lobed to 1-ternate, lobes or leaflets linear to obovate, entire to lobed
        5. Petals yellow throughout; sepals 4.5–8 mm; fruit body sides smooth or slightly papillate on sides
R. flabellaris
        5' Petals white, bases yellow or not; sepals 1.5–5 mm; fruit body cross-ridged
          6. Receptacle in fruit hairy; fruits 15–many, bodies 1–2 mm; submersed leaves 3–6-dissected; perennial herb
R. aquatilis var. hispidulus
          6' Receptacle in fruit glabrous; fruits 2–6, bodies 2–3 mm; submersed leaves generally 2–3-dissected; annual
R. lobbii
  1' Plant generally terrestrial (if aquatic stem generally emergent); petals generally yellow (sometimes white or reddish throughout)
    7. Basal leaf entire to crenate or lobed << 1/2 way to midrib or blade base
      8. Stem erect to generally prostrate or reclining, often rooting at lower nodes, stolon-like or from stolons
        9. Basal leaf blade linear to lanceolate, base generally tapered
R. flammula
        9' Basal leaf blade elliptic to reniform, base generally rounded or lobed
          10. Leaf generally crenate; fruit cluster cylindric, body striate to ridged on sides; major roots slender, not narrowed to stem
R. cymbalaria var. saximontanus
          10' Leaf ± entire; fruit cluster spheric, body smooth to striate on sides; major roots thick, narrowed to stem
R. gormanii
      8' Stem decumbent to generally erect, not rooting at nodes, not stolon-like, not from stolons
        11. Petals 1–3, 1–3 mm, ± = sepals; fruit body 0.9–1.5 mm
          12. Sepals 3; upper cauline leaf lanceolate to ovate; fruit body smooth to finely net-like
R. bonariensis var. trisepalus
          12' Sepals 5; upper cauline leaf linear to oblong; fruit body rough to minutely papillate
R. pusillus
        11' Petals 5–many, 3–15 mm, generally > sepals; fruit body 1–2.5 mm
          13. Sepals 1–3.5 mm, ± spreading; petals 3–6.5 mm; cauline leaf blade ovate to cordate, entire to barely toothed
R. populago
          13' Sepals 3–7 mm, ± reflexed; petals 5–15 mm; cauline leaf blade linear to lanceolate, entire or deeply 2–3-lobed
            14. Upper cauline leaf linear to narrowly lanceolate, entire; stems generally 3–5 from base, generally branched from base
R. alismifolius
              15. Basal leaf blade 2–4 cm, generally ovate
var. alismellus
              15' Basal leaf blade 4–12 cm, lanceolate to oblong
var. alismifolius
            14' Upper cauline leaf 0 or oblong to ovate, entire or generally deeply 2–3-lobed; stems generally 1 from base, sometimes few-branched above
R. glaberrimus
              16. Basal leaf elliptic to obovate; upper cauline leaf 0 or with terminal lobe generally > lateral
var. ellipticus
              16' Basal leaf ovate to round; upper cauline leaf 0 or with lobes generally ± equal
var. glaberrimus
    7' Basal leaf generally lobed > 1/2 way to midrib or blade base to dissected or compound
      17. Leaf blades generally glabrous, petiole hairs very sparse or generally 0
        18. Petals white, red-tinged or not; fruit body 8–15 mm, very compressed, sides 6–10 mm wide, margin wing-like; plant scapose
R. andersonii
        18' Petals yellow; fruit body < 7 mm, compressed to plump, sides < 4 mm wide, margin ± thick, not wing-like (but back sometimes keeled); plant scapose or generally not
          19. Fruit body 2–7 mm, beak 2–4 mm, cluster spheric
            20. Basal leaf toothed to deeply 3-lobed; fruit body sides spiny, back very keeled; annual, biennial
2 R. muricatus
            20' Basal leaf generally 1-ternate; fruit body sides smooth, back slightly keeled; perennial herb
R. orthorhynchus var. bloomeri
          19' Fruit body 1–2 mm, beak < 1 mm, cluster ovoid to subcylindric
            21. Annual; sepals 2–3 mm; petals 2–5 mm; flowers many, axillary, terminal; stem hollow below
R. sceleratus
            21' Perennial; sepals 3.5–7 mm; petals 5–12 mm; flowers few, terminal; stem solid
R. eschscholtzii
              22. Basal leaf with 3–5(7) lobes > 1/2 way to blade base, middle lobe with 1 tooth or lobe or generally entire, tips obtuse to rounded
var. oxynotus
              22' Basal leaf with 3 lobes > 1/2 way to blade base, middle lobe with 3 teeth or lobes, tips acute
var. suksdorfii
      17' Leaf blades generally soft-hairy to tomentose, petiole hairs generally > sparse
        23. Plant scapose; leaf 2–3-dissected, segments linear, ± entire; fruit body < beak, finely tomentose or glabrous, with 2 lateral bulges
R. testiculatus
        23' Plant not scapose; leaf entire, toothed, or deeply lobed to 1-compound, lobes or leaflets oblong to round, ± entire to deeply lobed or cut; fruit body generally > beak, sometimes puberulent but not tomentose, lenticular to ovoid, without bulges
          24. Fruit body sides papillate or spiny, puberulent or glabrous; annual, biennial
            25. Sepals ± 1–2 mm; petals 1–2 mm or 0; fruit body 1–3 mm, sides papillate, hairs curved
              26. Petals generally fewer than 5; basal leaf deeply 3–5-lobed to 1-ternate, lobes or leaflets oblanceolate to wedge-shaped, toothed to lobed; upper cauline leaf 3-lobed to 1-ternate
R. hebecarpus
              26' Petals generally 5; basal leaf coarsely toothed to deeply 3-lobed, lobes ± semicircular, toothed; upper cauline leaf entire to deeply 3-lobed
R. parviflorus
            25' Sepals 3.5–7 mm; petals 5–8 mm; fruit body 4–7 mm, sides spiny, hairs 0
              27. Basal leaf ± ovate to wedge-shaped; upper cauline leaf lobes linear to lanceolate or narrow-oblanceolate; fruits 4–10; fruit keel generally few-spined
R. arvensis
              27' Basal leaf cordate to reniform; upper cauline leaf lobes wide-oblanceolate; fruits generally 10–20; fruit keel not spiny
2 R. muricatus
          24' Fruit body sides ± smooth, not papillate (except sometimes in R. sardous), generally glabrous; perennial herb (annual, biennial in R. sardous)
            28. Stem prostrate to ascending, rooting at lower nodes, stolon-like or not
R. repens
            28' Stem ± prostrate to erect, not rooting at nodes, not stolon-like
              29. Petals 2–8 mm, = or 1–2.5 mm > sepals
                30. Basal leaf ovate to deltate, generally 1-ternate, leaflets stalked; sepals 3–6 mm; petals 4–8 mm; fruit beak ± straight or slightly curved
R. macounii
                30' Basal leaf generally cordate, deeply 3-lobed; sepals 1.5–3 mm; petals 2–5.5 mm; fruit beak curved
R. uncinatus
              29' Petals 4–19 mm, generally 3+ mm > sepals
                31. Caudex bulb-like; sepals generally spreading, hairs 0-sparse — North Coast (waif)
R. bulbosus
                31' Caudex 0 or not bulb-like; sepals generally puberulent to hairy, generally reflexed (except in R. acris)
                  32. Receptacle, especially in fruit, puberulent to hairy
                    33. Petals 7–22, blade generally oblong to obovate, length generally 2 × width
2 R. californicus
                    33' Petals 5–8, blade generally widely obovate to round, length generally < 2 × width
                      34. Basal leaf cordate to generally ovate, leaflets generally 5; fruit body 2–4 mm, beak 2–4 mm, ± straight
R. orthorhynchus var. orthorhynchus
                      34' Basal leaf ovate to generally cordate, leaflets generally 3; fruit body 2–3 mm, beak < 0.5 mm, ± straight to curved
R. sardous
                  32' Receptacle, especially in fruit, generally glabrous
                    35. Basal leaf pentagon-shaped, deeply lobed; sepals spreading
R. acris
                    35' Basal leaf ovate to cordate or round, deeply lobed to compound; sepals generally reflexed
                      36. Fruit body 3.5–5.5 mm, sides 3–4.5 mm wide
R. canus
                      36' Fruit body 2–4 mm, sides 1.5–3.5 mm wide
                        37. Petals generally 7–22; fruit beak generally 0.5–1 mm, generally curved
2 R. californicus
                        37' Petals generally 5–6; fruit beak generally 1.5–2.5 mm, curved or ± straight
R. occidentalis

Comments or questions on page
University & Jepson Herbaria Home Page |
General Information | University Herbarium | Jepson Herbarium |
Visiting the Herbaria | On-line Resources | Research |
Education | Related Sites |

Copyright by the Regents of the University of California