BIOL 317: Plant Identification and Classification Summer 2015 - Notes Week 4 – Tuesday • Juncaceae (rush family) • 7 genera, 430 spp. • distributed widely, but especially diverse in temperate and montane regions, often in wetlands • herbaceous; many aQuatic; often with rhizomes • leaves - simple; basal or alternate and 3-ranked; linear or cylindrical; open or closed sheath • stem - round and solid • flowers • actinomorphic • tepals 6, scarious (thin and dry) and persistent • stamens 6 • pistil compound (3 carpels); ovary superior • fruit: capsule • Cyperaceae (sedge family) • 98 genera, 5430 spp. • distributed widely, often in wetlands • herbaceous; many aQuatic; usually with rhizomes • leaves - simple; basal or alternate and 3-ranked; linear or cylindrical; closed sheath • stem – usually triangular and solid, but some are round • inflorescence • spikelet, usually subtended by 1 bract, usually part of larger inflorescence • flowers • subtended by 1 bract • actinomorphic • tepals 0, or 3-6 reduced to scales or bristles • stamens 1-3 • pistil compound (usually 3 carpels), but only 1 carpel with 1 ovule matures; ovary superior • fruit: achene • some species with unisexual flowers, monoecious plants • genus Carex – largest genus in family and among largest genera of angiosperms, ~1800 spp. • perigynium – bottle-shaped bract surrounding female flower • ligule – flap of tissue on inner surface of leaf where blade meets sheath • Poaceae/Gramineae (grass family) • 707 genera, 11337 spp. (among the largest angiosperm families) • most economically-important family as source of food and ecologically important as dominant members of grassland ecosystems • distributed worldwide, often in drier habitats • herbaceous; often with rhizomes or stolons • leaves - simple; basal or alternate and 2-ranked; linear; usually open sheath • ligule – flap of tissue on inner surface of leaf where blade meets sheath • stem (culm) – usually round and hollow • swollen nodes – gives stem jointed appearance • intercalary meristem – groups of stem cells at base of leaves and nodes allow for regrowth after leaf and shoot tips have been grazed/mown • inflorescence • spikelet, usually subtended by 2 bracts (glumes), usually part of larger inflorescence • flowers (florets) • subtended by 2 bracts – lemma (outer, larger bract) and palea (inner, smaller bract) • zygomorphic • tepals 2, reduced to small scales (lodicules) • stamens 3 • pistil compound (usually 3 carpels), but only 1 carpel with 1 ovule matures; ovary superior • fruit: caryopsis (achene in which fruit wall is fused to seed coat) • some species with unisexual flowers, monoecious plants Juncaceae Cyperaceae Poaceae Leaves closed or open closed sheath; ligule open sheath; sheath; ligule absent present only in Carex ligule present Stem round and solid triangular or round, round and hollow and solid Perianth 6 tepals none or reduced reduced Fruit capsule achene caryopsis (achene) • Trends in angiosperm evolution (ancestral state èderived) • woody habit è herbaceous • flower morphology • radial symmetry è bilateral • many organs è fewer, set number of organs • spiral arrangement è whorled • organs free è fused • perianth undifferentiated (tepals) è perianth differentiated into sepals and petals • stamens undifferentiated (laminar) è stamens differentiated into filament and anther • ovary superior è inferior • flowers perfect è unisexual ANITA grade • paraphyletic group (grade) comprising three clades (~175 spp. total) • Amborellaceae – includes only one species Amborella trichopoda • Nymphaeales – includes Nymphaeaceae • Austrobaileyales – includes 3 families: Schisandraceae (including the former Illiciaceae – star-anise), Trimeniaceae, and Austrobaileyaceae • mostly tropical and subtropical plants that have retained many ancestral character states • Nymphaeaceae (water-lily family) • 3 genera, 58 spp. • distributed widely in aquatic habitats • herbaceous; aquatic; with rhizomes • leaves - simple; variously arranged; peltate or subpeltate • flowers • actinomorphic • sepals 4-12 • petals usually many; intergrades with stamens • stamens usually many; often laminar • pistil usually compound (usually many carpels); ovary superior or inferior • fruit: berry or capsule Magnoliids • clade comprising four orders (~10,000 spp. total, 3.3% of angiosperms) • mostly tropical, subtropical, and warm-temperate plants that have retained many ancestral character states • ethereal oils common, giving plants a "primitive odor" (also found in Austrobaileyales); function as defense against herbivores • other important families include Annonaceae (cherimoya, soursop, pawpaw), Myristacaceae (nutmeg), Lauraceae (bay laurel), and Piperaceae (black pepper) • Magnoliaceae (magnolia family) • 2 genera, 227 spp. • distributed in eastern Asia, eastern North America, and tropical South America • woody (mostly trees) • leaves - simple; alternate; sheathing stipule; pinnate venation • flowers • actinomorphic • tepals 6 to many • stamens many, laminar • pistils simple, many; ovary superior • elongate receptacle • fruit: aggregate of follicles (Magnolia) or samaras (Liriodenderon) Week 4 – Thursday Eudicots/Tricolpates • includes ~75% of angiosperms • shared traits • tricolpate pollen (3 apertures/openings) § ancestral state is monosulcate pollen (1 aperture), found in most angiosperms outside the eudicots • perianth differentiated into sepals and petals • perianth organs in whorls, rather than spirally arranged • perianth organs in multiples of four or five (4- or 5-merous) • stamens differentiated into anther and filament "Basal eudicots" • paraphyletic group comprising about four orders • other important families include Papaveraceae (poppy), Berberidaceae (barberry, Oregon grape), Proteaceae (protea), and Platanaceae (sycamore) • Ranunculaceae (buttercup family) • 62 genera, 2525 spp. • distributed widely, especially in the northern temperate zone • usually herbaceous; some vines and shrubs • leaves – simple or compound; basal or alternate; usually no stipules • flowers • actinomorphic or zygomorphic • sepals usually 5, often showy • petals usually 5 • stamens many • pistils simple, usually several to many; ovary superior • fruit: aggregate of follicles, achenes, or berries • includes PNW wildflowers (Aquilegia spp. - columbine, Delphinium spp. - larkspur, Anemone spp., etc.) and ornamentals (Helleborus spp. – Lenten rose, Clematis spp., etc.) Core eudicots • morphologically heterogeneous clade Saxifragales • basally fused carpels common • other important families include Hamamelidaceae (witch-hazel), Paeoniaceae (peony), and Grossulariaceae (currant) • Saxifragaceae (saxifrage family) • 33 genera, 600 spp. • distributed in northern temperate zone and adjacent montane areas; especially diverse in western North America • herbaceous; many with rhizomes or stolons • leaves – simple or compound; often basal or alternate; usually no stipules • flowers • hypanthium (usually cup-shaped structure formed by fusion of base of sepals, petals, and stamens) • usually actinomorphic, some zygomorphic • sepals usually 5 • petals usually 5 • stamens 5 or 10 • pistils simple, usually 2; or compound (usually 2 carpels); amount of fusion at carpel base varies; ovary superior to inferior • fruit: 2 follicles or septicidal capsule • includes PNW wildflowers (Tellima grandiflora - fringecup, Micranthes spp. - saxifrages, Heuchera spp. - alumroot, etc.) and ornamentals (Astilbe spp., Heuchera spp., etc.) • Crassulaceae (stonecrop family) • 34 genera, 1400 spp. • distributed widely, usually in arid habitats • herbaceous or shrubby; succulent (leaves and stems thickened and fleshy to store water) • crassulacean acid metabolism (CAM) – a form of photosynthesis in which stomata open and allow carbon dioxide to be fixed at night and fixed carbon is converted to sugars using sunlight during the day. Thus, stomata can remain closed during the day to reduce water loss. • leaves - simple; variously arranged • flowers • actinomorphic • sepals 4 or 5 • petals 4 or 5 • stamens 4, 5, 8, or 10 • pistil simple, 4 or 5, basally fused; ovary superior • fruit: aggregate of follicles • includes PNW wildflowers (Sedum spp. – stonecrops) and ornamentals (Crassula ovata – jade plant, Kalanchoe spp., etc.) Rosids • morphologically heterogeneous clade Wind-pollination syndrome • Common traits: • flowers do not attract animal pollinators • reduced or no perianth • small • no reward • high pollen:ovule ratio • large anthers • unisexual flowers, with more staminate than pistillate flowers • large number of flowers • stigmas large and plumose or papillate • inflorescence: catkins – often pendulous spike of unisexual inconspicuous flowers • flowers emerge before leaves • Wind-pollinated dicots once thought to be primitive and form a clade (“Amentiferae”) • wind-pollination now known to have evolved independently multiple times from animal-pollinated ancestors • Fagales • common traits: • woody • unisexual flowers, monoecious plants • perianth reduced or none • staminate flowers in catkins • ovary inferior • fruit indehiscent • another important family is Juglandaceae (walnut) • Fagaceae (oak family) • 7 genera, 670 spp. • distributed in northern temperate and subtropical zone • woody (trees and shrubs) • leaves - simple; alternate; stipules • inflorescence • staminate flowers in small groups subtended by bract, on catkin • pistillate flowers in small groups (1-3), subtended by cupule (involucre/whorl of bracts) • flowers • unisexual, plant monoecious • actinomorphic • tepals 6, reduced