Patrick J. Vogan

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We demonstrate for the first time the presence of species exhibiting C3-C4 intermediacy in Heliotropium (sensu lato), a genus with over 100 C3 and 150 C4 species. CO2 compensation points (Gamma) and photosynthetic water-use efficiencies (WUEs) were intermediate between C3 and C4 values in three species of Heliotropium: Heliotropium convolvulaceum (Gamma =(More)
This study investigated whether Euphorbia subgenus Chamaesyce subsection Acutae contains C(3)-C(4) intermediate species utilizing C(2) photosynthesis, the process where photorespired CO(2) is concentrated into bundle sheath cells. Euphorbia species in subgenus Chamaesyce are generally C(4), but three species in subsection Acutae (E. acuta, E. angusta, and(More)
This study evaluates acclimation of photosynthesis and stomatal conductance in three evolutionary lineages of C3, C3–C4 intermediate, and C4 species grown in the low CO2 and hot conditions proposed to favo r the evolution of C4 photosynthesis. Closely related C3, C3–C4, and C4 species in the genera Flaveria, Heliotropium, and Alternanthera were grown near(More)
Plants using the C(4) pathway of carbon metabolism are marked by greater photosynthetic water and nitrogen-use efficiencies (PWUE and PNUE, respectively) than C(3) species, but it is unclear to what extent this is the case in C(3) -C(4) intermediate species. In this study, we examined the PWUE and PNUE of 14 species of Flaveria Juss. (Asteraceae), including(More)
Observations of insects visiting strongly protandrous flowers of Tolmiea menziesii (Saxifragaceae) show that Gnoriste megarrhina (Mycetophilidae), a large fungus gnat with a body ca. 7 mm long and a proboscis ca. 6.5 mm long, is the primary pollinator. Pollen is transferred to ventral portions of the gnat’s thorax while it probes for an unusually dilute(More)
Increasing the frequency of resistance to the non-native fungus Cronartium ribicola (causative agent of white pine blister rust, WPBR) in limber pine populations is a primary management objective to sustain high-elevation forest communities. However, it is not known to what extent genetic disease resistance is costly to plant growth or carbon economy. In(More)
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