Observation 66416: Uromyces pisi-sativi
When: 2011-04-25
(46.33889° 13.53691° )
No herbarium specimen

Notes: This rust fungus modifies its host plant Euphorbia cyparissias. Infected plants usually don’t produce fertile flowers and are much more slender and taller than normal. But they form a kind of pseudo-flowers, a rosette of leaves at the top of stalks resembling true flowers. Fungus produces nectar similar to nectar of healthy plants. It attracts ants and other insects, both on healthy and infected plants. For over 100 years this host-pathogen pair has been subject to much speculation concerning the function of nectar-producing spermatia. Today, it is generally assumed that they are produced to attract insects for fungal fertilization (more in Ref.: 4.).

Habitat: Relatively dry sandy grassland, grazed by sheep, shallow soil, almost flat terrain, full sun, exposed to direct rain, average precipitations ~ 3.000 mm/year, average temperature 8-10 deg C, elevation 540 m (1.800 feet), alpine phytogeographical region.

Substratum: Euphorbia cyparissias plant

Code: Bot_509/2011_DSC7362

Place: above the road to Plužna village, Bovec basin, East Julian Alps, Posočje, Slovenia EC

Nikon D700 / Nikkor Micro 105mm/f2.8 and Canon G11, 6.1-30mm/f2.8-4.5

Species Lists

Images

143305
Vegetation producing pustules called uredia.
143306
Vegetation producing pustules called uredia.
143307
Normal and infected plants intermixed in large groups.
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143309
Habitat of infected Euphorbia cyparissias.
143310
Urediniospores produced by orange vegetation producing pustules uredia,
143311
Urediniospores produced by orange vegetation producing pustules uredia,

Proposed Names

57% (1)
Eye3 Eyes3
Recognized by sight
Based on microscopic features: Urediniospores finely warty, dimensions: 24.0 (SD = 1.2) x 21.5 (SD = 0.7) micr., Q = 1.12 (SD = 0.07), n = 25. Motic B2-211A, magnification 1.000 x, oil, in water.

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Eye3 = Observer’s choice
Eyes3 = Current consensus

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Created: 2011-04-27 03:50:20 PDT (-0700)
Last modified: 2011-04-27 03:50:21 PDT (-0700)
Viewed: 126 times, last viewed: 2016-10-23 01:56:49 PDT (-0700)
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