BIOL 317: Plant Identification and Classification Summer 2015 - Notes

Week 6 – Tuesday  Plant reproduction and breeding systems(cont.)  Advantages of different breeding systems • asexual reproduction and selfing . reproductive assurance - can reproduce even in small, isolated populations . reduced reproductive effort - no need to produce showy flowers or flowers at all . locally adapted offspring in stable environments . 100% of genes passed to offspring • outcrossing . greater genetic variability in offspring - especially useful in changing environments . reduces inbreeding depression - maintenance of heterozygosity hides expression of deleterious recessive alleles

 Myrtales  other important families include Lythraceae (loosestrife, crape myrtle, pomegranate) and Myrtaceae (eucalyptus, guava, allspice)

 Onagraceae (evening-primrose family)  22 genera, 656 spp.  distributed widely, but especially diverse in western North America and South America  herbaceous or woody (shrubs)  leaves - simple; variously arranged  flowers • actinomorphic or zygomorphic • hypanthium common • sepals usually 4 • petals usually 4 • stamens 4 or 8 . pollen held in strands by sticky viscin threads • pistil compound (4 carpels); ovary inferior • fruit: capsule or berry  includes PNW wildflowers (Chamerion angustifolium - fireweed, Oenothera spp. - evening-primrose, Epilobium spp. - willowherb, Clarkia spp., etc.) and ornamentals (Fuchsia spp. - fuchsia, Oenothera spp., Epilobium spp., etc.)

 Brassicales  other important families include Capparidaceae (caper; sometimes included in expanded Brassicaceae) and Caricaceae (papaya)

 Brassicaceae/Cruciferae (mustard family)  338 genera, 3710 spp.  distributed widely, but especially diverse in northern temperate zone  herbaceous  leaves - simple or compound; alternate or basal  flowers • usually actinomorphic • sepals 4 • petals 4, often forming cross shape • stamens 6 . tetradynamous - 4 long inner stamens and 2 short outer stamens • pistil compound (2 carpels); ovary superior • fruit: silique (long and skinny, >2 times longer than wide) or silicle (round, <2 times longer than wide) . persistent replum - "false" septum with thickened placenta around margin  glucosinolates - sulfur-containing chemical compounds are transformed by the enzyme myrosinase into isothiocyanates (mustard oils) for herbivore defense  includes PNW wildflowers (Erysimum spp. - wallflower, Phoenicaulis cheiranthoides - daggerpod, Arabis spp. - rockcress, etc.), weeds (Alliaria petiolata - garlic mustard, Capsella bursa-pastoris - shepherd's purse, Cardamine hirsuta - bittercress, etc.), food crops (Brassica oleracea - cabbage, kale, Brussels sprouts, broccoli, cauliflower, kohlrabi; Brassica rapa - turnip, Chinese cabbage; Brassica nigra - mustard, Brassica napus - canola, Raphanus sativus - radish, Eruca sativa - arugula, Armoracia rusticana - horseradish, Eutrema japonicum - wasabi, etc.), model system in biological research (Arabidopsis thaliana), and ornamentals (Erysimum spp., Lunaria annua - honesty, Lobularia maritima - sweet alyssum, etc.)

 Sapindales  other important families include Anacardiaceae (sumac, poison ivy, mango, cashew) and Rutaceae (citrus)

 Aceraceae (maple family)  2 genera, 113 spp.  distributed in northern temperate zone  woody (trees or shrubs)  leaves - simple or compound; opposite; often palmately lobed  flowers • some unisexual, especially in wind-pollinated species; plants monoecious, dioecious, or androdioecious (some plants with perfect flowers, some plants with staminate flowers) • actinomorphic • sepals 4-5 • petals 4-5; some reduced, especially in wind-pollinated species • stamens 4-10 . some form nectary disk at base of stamens • pistil compound (2 carpels); ovary superior • fruit: samaroid schizocarp (splits into one-carpel sections; each section is winged)  species in Sapindaceae sensu stricto, which includes mostly tropical members with more diverse floral morphologies, formed a paraphyletic group when Aceraceae was excluded, so more recent classifications have expanded Sapindaceae to include Aceraceae  includes PNW trees and shrubs (Acer macrophyllum - big-leaf maple, Acer circinatum - vine maple, Acer glabrum - Douglas maple), food crop (Acer saccharum - sugar maple [source of maple syrup]), and ornamentals (Acer palmatum - Japanese maple, etc.)

 Malvales

 Malvaceae  former families Bombacaceae, Sterculiaceae, and Tiliaceae were polyphyletic groups, so more recent classifications have expanded Malvaceae to include members of all these families  the expanded Malvaceae includes a more morphologically heterogeneous group, including Theobroma cacao (cacao [source of chocolate]), Tilia spp. (linden), Durio zibethinus (durian), and Adansonia spp. (baobab)

 Malvaceae sensu stricto (mallow family)  78 genera, 1670 spp.  distributed widely  herbaceous or woody (shrubs)  leaves - simple or palmately compound; alternate; stipulate  stellate hairs (multi-branched hairs) common on stems and leaves  mucilage canals in tissues

 flowers • actinomorphic • epicalyx (whorl of bracts subtending flower) common • sepals 5 • petals 5 • stamens usually many . monadelphous - filaments fused to form tube around pistil • pistil compound (5 to many carpels); ovary superior • fruit: capsule or schizocarp  includes PNW wildflowers (Sphaeralcea spp. - globemallow, Iliamna spp. - globemallow, etc.), food crop (Abelmoschus esculentus - okra), fiber crop (Gossypium hirsutum - cotton), and ornamentals (Hibiscus rosa-sinensis - Chinese hibiscus, Alcea rosea - hollyhock, etc.)

 Geraniales

 Geraniaceae (geranium family)  7 genera, 805 spp.  distributed in northern and southern temperate zones  herbaceous  leaves - simple or compound; variously arranged; usually stipulate  flowers • actinomorphic or zygomorphic • sepals 5 • petals 5 • stamens 5-15 • pistil compound (5 carpels); ovary superior . carpels surround persistent elongate column • fruit: schizocarp  includes PNW wildflowers (Geranium viscosissimum - sticky crane's-bill, etc.), weeds (Geranium robertianum - herb Robert, Erodium cicutarium - common stork's bill, etc.), and ornamentals (Geranium spp. - crane's-bill, Pelargonium spp. - geranium, etc.)

Week 6 – Thursday  Asterids  includes two early-diverging orders and the core Asterids  synapomorphies • iridoid compounds - class of monoterpene chemicals used as defense against herbivores • unitegmic ovules - single integument layer; secondary reduction in number of integuments in angiosperms • tenuinucellate ovules - thin nucellus layer around embryo sac

 Cornales  another important family is Hydrangeaceae (hydrangea)

 Cornaceae (dogwood family)  2 genera, 85 spp. (65 spp. in Cornus)  distributed in northern temperate zone  woody (trees or shrubs)  leaves - simple; usually opposite; secondary veins arch toward leaf apex; spiral thickenings around vessel elements hold leaf together when torn  T-shaped hairs (two-branched hairs) on stems and leaves  inflorescence • usually corymbose, or capitate (head-like) and subtended by showy bracts  flowers • actinomorphic • sepals 4, reduced • petals 4 • stamens 4 • pistil compound (2-3 carpels); ovary inferior • fruit: drupe  includes PNW trees, shrubs, and wildflowers (Cornus nuttallii - Pacific dogwood, Cornus sericea - red osier dogwood, Cornus unalaschkensis - western bunchberry), regional food crop (Cornus mas - cornelian cherry), and ornamentals (Cornus florida - flowering dogwood, etc.)

 Ericales  other important families include Sarraceniaceae (New World pitcher-plant), Primulaceae (primrose), and Theaceae (camellia)

 Polemoniaceae (phlox family)  18 genera, 385 spp.  distributed in northern temperate zone and in Andean South America, but especially diverse in western North America  herbaceous or woody at base (sub-shrubs)  leaves - simple or compound; variously arranged  flowers • actinomorphic • sepals 5, fused • petals 5, fused • stamens 5, epipetalous • pistil compound (3 carpels); ovary superior • fruit: capsule  includes PNW wildflowers (Phlox spp. - phlox, Polemonium spp. - Jacob's-ladder, Collomia spp., etc.) and ornamentals (Phlox paniculata - garden phlox, etc.)

 Ericaceae (heather family)  126 genera, 4010 spp.  distributed widely, but especially diverse in montane tropics and prominent in boreal to temperate habitats  herbaceous or woody (trees or shrubs)  leaves - simple; variously arranged; often thick and leathery  flowers • actinomorphic or slightly zygomorphic • sepals usually 5 (some 4) • petals usually 5 (some 4), usually fused; often urn-shaped and pendulous or funnel-shaped • stamens usually 10 (some 8), some epipetalous . anthers release pollen via pores at tip (poricidal dehiscence) • pistil compound (usually 3-5 carpels); ovary superior or inferior • fruit: capsule, berry, or drupe  strong associations with fungi (mycorrhizae) • some have become parasitic on fungi (mycotrophy)  includes PNW trees, shrubs, and wildflowers (Arbutus menziesii - madrone, Gaultheria shallon - salal, Cassiope mertensiana - mountain heather, Arctostaphylos uva-ursi - kinnikinnick, Vaccinium spp. - huckleberry, Rhododendron macrophyllum - Pacific rhododendron, etc.), food crops (Vaccinium corymbosum - blueberry, Vaccinium oxycoccos - cranberry), and ornamentals (Calluna vulgaris - summer heather, Rhododendron spp., etc.)