, Volume 72, Issue 4, pp 533–541 | Cite as

Stem photosynthesis in a desert ephemeral, Eriogonum inflatum

Morphology, stomatal conductance and water-use efficiency in field populations
  • S. D. Smith
  • C. B. Osmond
Original Papers


Seasonal patterns in plant morphology, phenology, and physiology were monitored in several populations of Eriogonum inflatum, a desert ephemeral which produces a large photosynthetic inflorescence above a basal leaf rosette. Green stems accounted for 66–77% of whole plant photosynthetic surface area when integrated over a developmental cycle, whereas only 40–67% of the yearly transpirational water loss could be attributed to stems. Stems were found to have lower nitrogen and chlorophyll contents than leaves, and lower stomatal conductance under all physiological conditions encountered. However, because stems occur later in the year than leaves, comparison of physiological patterns was complicated by the two structures being exposed to different climatic regimes during their developmental cycles. Stems exhibited higher δ13C values than leaves, indicating that stems operated at higher water-use efficiencies than leaves, at least during periods when both leaves and stems were present. Higher water-use efficiency in stems of E. inflatum is attributed to both more conservative water use patterns and to their vertical orientation, allowing stems to remain photosynthetically active longer into the dry season after senescence of the horizontal leaf rosette.

Key words

δ13Eriogonum inflatum Great Basin Mojave Photosynthetic morphology Stem photosynthesis Water-use efficiency 


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  1. Anderson DA, Szarek SR (1981) Ecophysiological studies on Sonoran Desert plants, VI. Seasonal photosynthesis and production of Machaeranthera gracilis, a winter ephemeral. Plant Cell Env 4:243–250Google Scholar
  2. Beatley JC (1974) Phenological events and their environmental triggers in Mojave Desert ecosystems. Ecology 55:856–863Google Scholar
  3. Blattner P, Hulston JR (1978) Proportional variations of geochemical δ13C scales — an interlaboratory comparison. Geochim Cosmochim Acta 42:59–62Google Scholar
  4. Craig H (1957) Isotopic standards for carbon and oxygen and correction factors for mass-spectrometric analysis of carbon dioxide. Geochim Cosmochim Acta 12:133–149Google Scholar
  5. Downton WJS, Berry JA, Seemann JR (1984) Tolerance of photosynthesis to high temperature in desert plants. Plant Physiol 74:786–790Google Scholar
  6. Ehleringer J (1983) Ecophysiology of Amaranthus palmeri, a Sonoran Desert summer annual. Oecologia (Berlin) 57:107–112Google Scholar
  7. Ehleringer, J, Forseth I (1980) Solar tracking by plants. Science 210:1094–1098Google Scholar
  8. Ehleringer J, Mooney HA, Berry JA (1979) Photosynthesis and microclimate of Camissonia claviformis, a desert winter annual. Ecology 60:280–286Google Scholar
  9. Farquhar GD, Richards RA (1984) Isotopic composition of plant carbon correlates with water-use efficiency of wheat genotypes. Aust J Plant Physiol 11:539–552Google Scholar
  10. Farquhar GD, Ball MC, von Caemmerer, S, Roksandic Z (1982a) Effect of salinity and humidity on the δ13C value of halophytes — evidence for diffusional isotope fractionation determined by the ratio of intracellular/atmospheric partial pressure of CO2 under different environmental conditions. Oecologia (Berlin) 52:121–124Google Scholar
  11. Farquhar GD, O'Leary MH, Berry JA (1982b) On the relationship between carbon isotope discrimination and the intercellular carbon dioxide concentration in leaves. Aust J Plant Physiol 9:121–137Google Scholar
  12. Ferris RS (1974) Death Valley Wildflowers. Death Valley Natural History Association, Death Valley, 311 pGoogle Scholar
  13. Forseth IN, Ehleringer JR (1982) Ecophysiology of two solar tracking desert winter annuals. II. Leaf movements, water relations and microclimate. Oecologia (Berlin) 54:41–49Google Scholar
  14. Forseth IN, Ehleringer JR (1983) Ecophysiology of two solar tracking desert winter annuals. IV. Effects of leaf orientation on calculated daily carbon gain and water-use efficiency Oecologia (Berlin) 58:10–18Google Scholar
  15. O'Leary MH (1981) Carbon isotope fractionation in plants. Phytochemistry 20:553–567Google Scholar
  16. Osmond CB, Smith SD, Ben Gui-Ying, Sharkey TD (1987) Stem photosynthesis in a desert ephemeral, Eriogonum inflatum: Characterization of leaf and stem CO2 fixation and H2O vapor exchange under controlled conditions. Oecologia (Berlin) 72:542–549Google Scholar
  17. Osmond CB, Valaane N, Haslam SM, Uotila P, Roksandic Z (1981) Comparisons of δ13C values in leaves of aquatic macrophytes from different habitats in Britain and Finland; some implications for photosynthetic processes in aquatic plants. Oecologia (Berlin) 50:117–124Google Scholar
  18. Price PW (1982) Wild buckwheat Eriogonum inflatum (Polyonaceae): an enigmatic plant. Southwest Nat 27:247–253Google Scholar
  19. Schulze E-D, Lange OL, Evenari M, Kappen L, Buschbom U (1980) Long-term effects of drought on wild and cultivated plants in the Negev Desert. II. Diurnal patterns of net photosynthesis and daily carbon gain. Oecologia (Berlin) 45:19–25Google Scholar
  20. Smith SD, Nobel PS (1986) Deserts. In: Baker NR, Long SP (eds) Topics in Photosynthesis, Vol. 7. Elsevier, Amsterdam, pp. 13–62Google Scholar
  21. Vernon LP (1960) Spectrophotometric determination of chlorophylls and pheophytins in plant extracts. Anal Chem 32:1144–1150Google Scholar
  22. Werk KS, Ehleringer J, Forseth IN, Cook CS (1983) Photosynthetic characteristics of Sonoran Desert winter annuals. Oecologia (Berlin) 59:101–105Google Scholar

Copyright information

© Springer-Verlag 1987

Authors and Affiliations

  • S. D. Smith
    • 1
  • C. B. Osmond
    • 1
  1. 1.Biological Sciences CenterDesert Research InstituteRenoUSA

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