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But first, a review Nepenthes, a pitcher plant in the Caryophillid group
Rosids in general• Somewhat weakly supported• Hypanthium in a lot of groups• 18 orders• 114 families• 58,000 species• Over 1/3 of all dicots• Mostly apopetalous “separate petals”• Diverse group• Two major clades
Rosids I
• Very popular group in CO
• Economically important, many fruits
• We will study 14 families in this group
• Today, only four:– Crassulaceae– Grossulariaceae– Onagraceae– Euphorbiaceae
Crassulaceae
• Stone crop family• Most are SMALL SUCCULENTS• Regular, bisexual flowers• 1 or 2 times as many stamen as pistils• 3 or more simple pistils• 4 or 5 sepals• Sedum is a common species in Colorado• Family where Crassulacean Acid Metabolism
was first described• http://www.crassulaceae.com/
CAM
• Special metabolic pathway that helps plants live in hot, arid habitats
• Stomata open during the night to let in CO2
• The CO2 is fixed into an acid
• That acid then releases C into the Krebs cycle during the day when light is present
• Stomata are closed during the day
Grossulariaceae
• Gooseberry family• Includes currants • Mostly shrubs with palmate leaves• Shiny berries with attached sepals• Regular bisexual flowers, but small (1/4 in)• Five united sepals• Five separate petals• Five stamen• Inferior or superior ovary• Only ONE genus!!! – Ribes arguably
Grossularia• Ecologically important
Onagraceae
• Evening primrose family• FOUR-LOBED STIGMA• Four petals• Four sepals• Four (or 8) stamen• FOUR syncarpous (fused) carpels• INFERIOR OVARY• Capsule, berry, or drupe• Called evening primrose because
they generally open in the evening / late afternoon
Onagraceae
• Fireweed (Chamerion angustifolium)• Abundant after fires• Adapted to fire via underground rhizomes that
sprout up after fire • Lightweight seeds and many of them• After a certain time, other species come up and
outcompete it via light interception• Worldwide• Low resistance to human trampeling
Euphorbiaceae
• Euphorb family• Spurge family• MILKY SAP• Many are succulent• Can lack sepals• Can lack petals• Carpels 1-20• Superior ovary• Fruit is a schizocarpic capsule
Euphorbiaceae
• Convergent evolution
• Many euphorbs occupy the same niches in Africa that many of our cacti do
• Euphorbia is the only genus of plants known to have all three metabolic pathways: C3, C4, and CAM
Roots of Manihot esculentahttp://www.youtube.com/watch?v=Qtvhs0O2oJE