Transcript Rosids I
http://www.youtube.com/watch?v=trWzDlRvv1M But first, a review Nepenthes, a pitcher plant in the Caryophillid group Rosids I Crassulaceae Grossulariaceae Onagraceae Euphorbiaceae 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 CAM at night CAM during the day Sedum lanceolatum Stonecrop Clementsia rhodantha – Queen’s Crown Sedum rosea or Rhodiola integrifolia – King’s crown 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 Ribes cereum – wax currant Ribes cereum in fruit Ribes lacustre – Prickly currant 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 Onagraceae distribution Onagraceae – Four lobed stigma Onagraceae – Note the hypanthium Onagraceae in crosssection Oenothera caespitosa Oenothera caespitosa 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 Chamerion angustifolium Chamerion angustifolium 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 Euphorbiaceae Euphorbiaceae - Distribution Euphorbiaceae - Succulent Euphorbiaceae – milky sap Euphorbiaceae - flowers Euphorbiaceae - Cyanthium Poinsettia Cassava or manioc is in this family Roots of Manihot esculenta http://www.youtube.com/watch?v= Qtvhs0O2oJE