BSc in Biology

Light microscope photo of the cyanobacterium Anabaena azollae, with heterocytes

Scanning electron microscope photo of a pollen grain of Clivia

Tip of a stem of Cycas circinalis, with megasporophylls

One of the most common native lichens, Xanthoria parietina, with apothecia

Foliose liverwort Lophocolea heterophylla with sporogones

Branch of the common yew (Taxus baccata) with microsporangiate (= male) cones

Red alga, Delesseria sanguinea, Rhodophyta

Antheridial heads of Polytrichum

Branches of Ephedra distachya with seed between fleshy scales

Ovary of Narcissus pseudonarcissus, longitudinal section, showing numerous ovules

Branches with cones of European larch (Larix decidua); pollen cones yellow, ovulate cone red, mature seed cone brown

Peat moss (Sphagnum spec.) with sporogones

Fruiting body of the fly agaric (Amanita muscaria, Basidiomycetes)

Fruiting bodies (apothecia) of the Black Bulgar (Bulgaria inquinans, Ascomycetes)

Moss with sporogones

Embryo of a pea (Pisum sativum), one cotyledon separated, plumule (shoot bud) and radicle (initiation of primary root) clearly visible

Flower of Amborella trichopoda, sister group of all other angiosperms (often addressed as 'the most primitive living angiosperm')

Bladderwrack, Fucus vesiculosus (brown algae, Phaeophyceae)

Ovulate cone of a cypress (Cupressus), with pollination droplets on tubular micropyles

Green alga Ulva intestinalis

Immature cone of Larix decidua: longitudinal section (left); seed scale with two developing seeds (right)

Light microscope photo of a moss rhizoid

Scanning electron microscope photo of the peristome of Funaria hygrometrica

Light microscope photo of a section of a seed of Petunia axillaris; pericarp visible in the upper right hand corner, placenta in the lower right hand corner

Scanning electron microscope photo of Streptocarpus pollen grains

Root systems: allorhizal = with a primary root and secondary roots (left) and homorhizal = with more or less equal roots (right)

Storage roots (Campanula rapunculoides, left) and root tubers (Ficaria verna, right)

Dichasial vegetative branching in (Syringa vulgaris)

Spine (pointed woody brachyblast) of Prunus spinosa bearing flower buds

Phylloclades (leaf-like stems) of Ruscus aculeatus, in the right photo with a flower

Scandent plants: twining in Humulus lupulus (left); by shoot tendrils in Vitis vinifera (right)

Rhizome = a subterranean stem serving as storage organ, in Anemone nemorosa

Stolons = elongated stems as a means of vegetative reproduction in Potentilla anserina

Stolons forming tubers in Solanum tuberosum

The three basic types of leaf arrangement: 1 leaf per node = alternate (Veronica filiformis, left); 2 leaves per node = opposite (Stellaria graminea, center); > 2 leaves per node = verticillate (Hippuris vulgaris, right)

Photos of special cases of alternate leaf arrangement: distichous in Phalaris arundinacea (left); tristichous in Ceratrum album (center); spiral (3/8) in Hypochaeris radicata (right)

Perfect spirals in Romanesco cabbage (Brassica oleracea var. botrytis), organs following each other with the limit divergence angle of ca. 137.5°

Structures of the leaf base: stipules in Malus spec. (left); leaf sheath in Angelica archangelica (right)

Basic types of leaf venation: parallel in Deschampsia caespitosa (left); pinnate in Carpinus betulus (right)

Leaf margins, from left to right: entire (Syringa vulgaris); serrate (Forsythia intermedia); aculeate-dentate (Mahonia aquifolium); crenate (Glechoma hederacea); sinuate (Quercus petraea)

Palmately dissected leaves in Malva moschata

Pinnate leaf of a vetch (Vicia spec.), with stipules and tendrils

Palmately compound leaves of Lupinus polyphyllus

Simple racemose inflorescences, from left to right: raceme = axis elongate, flowers pedicellate (Brassica napus); spike = axis elongate, flowers sessile (Orobanche hederae); umbel = axis extremly short, flowers pedicellate (Astrantia major); capitulum = head = axis extremely short, flowers sessile (Scabiosa lucida)

Cymose inflorescences: dichasium (Stellaria holostea, left); scorpioid cyme (Symphytum officinale, right)

Compound inflorescences: panicle (Ligustrum vulgare, left); funnel-shaped corymb (Filipendula ulmaria, center); thyrse (Aesculus hippocastanum, right)

Inflorescences (catkins) of poplars (Populus spp.): pistillate (left) and staminate (right)

Flower of Gagea lutea, with a perigone = perianth parts more or less equal

Flower of Spergula arvensis, with perianth consisting of calyx and corolla

Apochlamydeous flowers (= without any perianth) of the common ash (Fraxinus excelsior)

Flower of Dianthus deltoides: actinomorphic = with more than 2 planes of symmetry

Flowers of the bleeding heart (Lamprocapnos spectabilis): disymmetric = with 2 planes of symmetry perpendicular to one another

Flowers of Euphrasia officinalis: zygomorphic = with a single plane of symmetry

Flowers of Corydalis cava, their spur chewed open by bumblebees

Flowers of Anemone nemorosa (Ranunculaceae), with a perigone = perianth parts more or less equal and a polymerous androecium = stamens numerous

Flowers with diplostemonous androeceum = twice as many stamens as petals (Oxalis corniculata, left) and with haplostemonous androeceum = as many stamens as petals (Sambucus nigra, right)

Different types of anther dehiscence: longicidal = lengthwise, the most common type (Lilium martagon, left), poricidal = with pores or very short slits (Solanum tuberosum, center), and valvate = with flaps (Mahonia aquifolium, right)

Fusion of filaments: with the corolla tube, leading to a joint stamen-corolla tube (Syringa vulgaris, left); with each other, leading to a filament tube separate from the corolla (Malva moschata, right)

Gynoecia: choricarpous = consisting of several free carpels (Helleborus niger, left); coenocarpous = consisting of several (here 3) fused carpels (Tropaeolum majus, right), note single style with 3 stigmatic branches

Ovary positions: superior = flower hypogynous = all other floral parts inserted below the insertion of the gynoecium (Hyacinthoides non-scripta, left); inferior = flower epigynous = all other flower parts inserted on top of the ovary (Galanthus nivalis, right)

Placentation types in choricarpous gynoecia: submarginal = along the ventral suture of the carpel (Aquilegia vulgaris, left) and laminal = scattered on the entire surface (Nymphaea), in cross section (center) and longitudinal section (right)

Placentation types in coenocarpous gynoecia: axile = in the center of a septate ovary (Tulipa gesneriana, left); parietal = on the ovary wall (Menyanthes trifoliata, right)

Free central placentation in Primula vulgaris: longitudinal section of flower (left); cross section of young fruit (right)

Open follicles in Eranthis hyemalis

Legumes of Vicia sativa: mature but still closed (left); dehisced (right)

Monocarpellate berries in Berberis thunbergii

Peach (Prunus persica), longitudinal section

Nutlets in Ranunculus sceleratus

Fleshy fruits with nutlets: strawberry (Fragaria x ananassa, left), with a buldging receptacle as the fleshy part; hip of Japanese rose (Rosa rugosa, right), with hypanthium as the fleshy part

Fruit consisting of drupelets in raspberry (Rubus idaeus); sepals, stamens and styles still preserved

Fruits (loculicidal capsules) of Iris pseudacorus

Septicidal capsule = opening in the plane of the septa in Digitalis purpurea

Capsules with special types of dehiscence: valvate by teeth in Silene dioica (left); poricidal = by pores in Papaver dubium (center); operculate = with a lid in Plantago lanceolata (right)

Fruits (siliques) of Erysimum cheiri

Longitudinal section of a tomato (Lycopersicon esculentum), a berry with fleshy pericarp and sarcotestal seeds

Cross section of an olive (Olea europaea), a bicarpellate drupe; testa, endosperm and embryo visible in the only developed seed, septum and an aborted ovule in the second locule visible; embedded in methacrylate resin

Immature fruits (acorns) of the common oak (Quercus robur); nuts in a cupule

Fruits (samaras) of Ulmus glabra

Fruit (schizocarp) of Anchusa arvensis

Schizocarps: Alcea rosea (left); Anthriscus sylvestris (center); Acer pseudoplatanus (right)

Laminaria, cross section of a thallus in the region of a sorus

Zygnematophyceae; left: Closterium; center: Micrasterias; right: Spirogyra

Peat moss (Sphagnum): habit (left) and detail of a phylloid in the light microscope (right)

Female reproductive structures of Pinus sylvestris; left: tip of branch with ovulate cone of the current year; right: light microscope photo of a longitudinal section of an ovule, two egg cells and boreholes in the nucellus caused by pollen tubes clearly visible

Strobili of a pine tree (Pinus); left: group of pollen cones; right: young ovulate cone at the time of pollination, pollination droplets visible on the cone scales

Prothallium of a leptosporangiate fern (left), with necks of archgonia (center) and antheridia (right)

Common horsetail (Equisetum arvense); left: part of a strobilus, in this case a spike of sporangiophores; right: cross section of a strobilus in the light microscope

Haircap moss (Polytrichum); left: habit; right: cross section of a phylloid in the light microscope

Bacillariophyceae; left: Pleurosigma; right: Arachnoidiscus

Groups of antheridia of mosses; left: Polytrichum, cauloids with terminal groups of antheridia seen from above; right: Mnium, light microscope photo of a longitudinal section of a group of antheridia

Capsella bursa-pastoris; left: silicule, just opening; medium left: replum with seeds; right: longitudinal section of a young seed in the light microscope

Light microscope photo of a longitudinal section of a microsporophyll of Pinus

Leaf details of Drypteris, a leptosporangiate fern; left: abaxial surface of a second order pinna, with sori; right: section of a sorus in the light microscope

Marchantia polymorpha; left: archegoniophore with sporogones in different stages of development, the outer ones already dehisced; right: light microscope photo of a longitudinal section of an immature sporogone

Flower buds of Campanula; left: longitudinal section, shortly before anthesis; right: cross section in the light microscope

Peristome of mosses; left: sporogone with spreading peristome teeth; right: persistome teeth in the light microscope

Chlorophyceae; left: Pediastrum; right: Oedogonium

Cyanobacteria; left: Chroococcus turgidus; right: Anabaena azollae, with heterocytes

Marchantia polymorpha; left: tips of thalli with archegoniophores; right: light microscope photo of a longitudinal section of an archegonium

Inflorescences of Liliaceae: solitary flower in Fritillaria meleagris (left), raceme in Lilium martagon (center), pseudo-umbel in Fritillaria imperialis (right)

Flowers of Liliaceae: Tulipa sylvestris (left) and Lilium bulbiferum (right), showing the typical construction of the family: actinomorphic, with 3+3 (sub)equal tepals, 3+3 stamens and a superior ovary consisting of three fused carpels

Ovary of Tulipa gesneriana: lateral view (left); cross section (right)

Fruits (loculicidal capsules) of Liliaceae: Tulipa gesneriana (left), Lilium regale (right)

Flowers of Asparagaceae: Anthericum liliago (left), with free tepals; Polygonatum multiflorum (right), with fused tepals

Asparagaceae fruits: loculicidal capsules in Muscari botryoides (left), berries in Convallaria majalis (right)

Inflorescences in Amaryllidaceae: many-flowered (pseudo-)umbel in Allium flavum (left); two-flowered umbel in Leucojum vernum (center); single flower in Galanthus nivalis (right)

Inflorescences in Asparagaceae: solitary flower in Asparagus officinalis (left); raceme in Muscari latifolium (right)

Amaryllidaceae flowers: Narcissus poeticus (left), with a paracorolla; Allium ursinum (right), an exception within the family because of its superior ovary

Flower of Galanthus nivalis (Amaryllidaceae), longitudinal section, showing inferior ovary

Amaryllidaceae fruits: Narcissus pseudonarcissus (left), a loculicidal capsule; Galanthus nivalis (right), a transitional form between capsule and berry

Crops plants in Amaryllidaceae: Onion (Allium cepa, left), longitudinal section of the bulb; Chives (Allium schoenoprasum, center), flowering plant; Leek (Allium porrum, right)

Pulsatilla vulgaris (Ranunculaceae)

Leaves of Ranunculaceae: undivided in Caltha palustris (left); bipinnate in Actaea racemosa (right)

Deeply palmately dissected leaf of Ranunculus acris (Ranunculaceae)

Flower of Helleborus niger (Ranunculaceae), seen from back side, with simple perianth and bracts below the flower

Flowers of Helleborus niger (Ranunculaceae), with nectar leaves between perianth and androecium

Petals derived from nectar leaves in Ranunculus acris (Ranunculaceae): entire flower, lateral view (left); single petal = nectar leaf (right), note nectar gland at the base

Flower of Aquilegia vulgaris (Ranunculaceae), with five spurred nectar leaves

Zygomorphic flowers in Ranunculaceae: spurred in Consolida regalis (left); helmet-shaped in Aconitum lycoctonum (right)

Flowers of a garden form of Delphinium elatum (Ranunculaceae): tip of a partial inflorescence (left); longitudinal section of a flower (right), with a nectar leaves reaching deeply into the spur, one of them removed and placed above the flower

The most common fruit types in Ranunculaceae: nutlets in Ranunculus sceleratus (left); follicles in Eranthis hyemalis (right)

Fruit of Clematis vitalba (Ranunculaceae): nutlets with densely pubescent styles

Actaea spicata, with its solitary carpel and berries an exception among the Ranunculaceae: flowers (left) and fruits (right)

Leaf bases of Rosaceae, with stipules: Malus spec. (left); Sorbus aucuparia (right)

Rosaceae flowers with epicalyx, seen from back side: Potentilla neumanniana (left), Fragaria ananassa (right)

Rosaceae flowers: Rosa multiflora (left), with the typical flower construction; Sanguisorba minor (right), with unisexual flowers arranged in a head

Longitudinal sections of Rosaceae flowers: Rosa rugosa (left), carpels enclosed in hypanthium; Geum rivale (right), carpels raised on a gynophore

Photos of the gynoecium position in Rosaceae: superior = flower hypogynous in Fragaria moschata (left); in hypanthium = flower perigynous in Prunus serotina (center); inferior = flower epigynous in Malus domestica (right)

Follicles of Physocarpus opulifolius (Rosaceae)

Photos of special nutlets in Rosaceae: Geum urbanum (left), with styles acting as barbs; Filipendula ulmaria (right), with twisted nutlets

Fruits consisting of druplets in Rosaceae: Rubus saxatilis (left); R. caesius (right)

Rosaceae, fleshy fruits with nutlets: strawberry (Fragaria x ananassa, left), with enlarged fleshy receptacle; hip of Japanese Rose (Rosa rugosa, right), hypanthium fleshy

Longitudinal sections of fleshy fruits of Rosaceae: Apple (Malus domestica, left), an inferior berry; Apricot (Prunus armeniaca, right), a drupe

Species showing the typical rough indument of Boraginaceae: Achusa azurea (left); Symphytum officinale (right)

Tip of the scorpioid cyme of Myosotis arvensis (Boraginaceae)

Flowers of Pentaglottis sempervirens (Boraginaceae), with protruding faucal scales

Zygomorphic flowers, a rare character in Boraginaceae: Echium vulgare (left), Anchusa arvensis (right)

Photo of a longitudinally opened corolla of Symphytum officinale (Boraginaceae), with faucal scales alternating with stamens

Immature fruit (schizocarp) of Pentaglottis sempervirens (Boraginaceae)

Photos of the characteristic vegetative characters of Lamiaceae: quadrangular stems and opposite leaves, in Lamium purpureum (left) und Lycopus europaeus (right)

Typical zygomorphic Lamiaceae flowers in Galeopsis bifida

Longitudinal section of a flower of Lamium maculatum (Lamiaceae)

Flower of Teucrium chamaedrys (Lamiaceae)

Calyces of Leonurus cardiaca (Lamiaceae), with almost mature fruits

Halophytic Brassicaceae on the shore of the Baltic sea: Crambe maritima (left); Cakile maritima (right)

Leaves in Brassicaceae: Capsella bursa-pastoris (left), undivided, sessile, amplexicaul; Barbarea vulgaris (center), pinnatifid, sessile, auriculate; Lunaria annua (right), cordate, petiolate

The typical inflorescence in Brassicaceae: ebracteate racemes, in Arabidopsis thaliana (left) and Brassica napus (right)

The typical flower construction in Brassicaceae, K4 C4 A2+4 G(2): Rorippa sylvestris (left); Cardamine amara (right)

Fruits in Brassicaceae: beaked silique in Eruca sativa (left); silicle in Thlaspi arvense (right)

Roots of Trifolium dubium (Fabaceae), with nodules

Fabaceae leaves: Trifolium dubium (left), with stipules at the base of the petiole; Phaseolus vulgaris (right), with stipellules at the bases of the petiolules

Pinnate leaf of Vicia sativa (Fabaceae), with tendrils derived from leaflets

Inflorescences of Fabaceae: almost capitulate in Trifolium badium (left); raceme in Melilotus albus (right)

Flowers of Fabaceae: Ornithopus perpusillus (left), with red-veined banner, paler wings and yellow keel; Lupinus polyphyllus (right), wings and half of the keel removed, showing the filament tube

Legumes of Vicia sativa (Fabaceae): still closed (left); dehisced (right)

Leaves in Caryophyllaceae: Cerastium fontanum (left), opposite, sessile, without stipules and apparently 1-nerved, the most common pattern in Caryophyllaceae; Spergula arvensis (center), pseudo-verticillate; Spergularia rubra (right), with membraneous interpetiolar stipules

Dichasial inflorescence of Stellaria aquatica (Caryophyllaceae)

Caryophyllaceae flowers: Spergularia rubra (left), with free sepals; Silene vulgaris (right), with fused sepals

Flowers of Silene dioica (Caryophyllaceae), opened longitudinally: female (left) and male (right)

Photo of a capsule of Cerastium fontanum (Caryophyllaceae), opening by teeth

Alopecurus pratensis (Poaceae): upper end of leaf sheath, with ligule (left); longitudinal section of culm, with solid node (right)

Panicle branch of Poa pratensis (Poaceae), with flowering spikelets

Poaceae spikelets: Bromus secalinus (left), lemmae with awns; Briza media (right), without awns

Spikelet and flower parts of Festuca rubra (Poaceae): on the left three closed flowers, a lemma (with awn) and a palea (without awn) removed; in the center and on the right two flowers without their floral bracts

Fruiting spikelets of Arrhenatherum elatius (Poaceae), with bent awns

Stems and leaves of Juncaceae: Luzula campestris (left), with pubescent leaf sheath; Juncus effusus (center), longitudinal section of leaf; Juncus articulatus (right)

Inflorescence of Luzula campestris (Juncaceae)

Flowers of Juncus tenuis (Juncaceae)

Infructescence of Juncus inflexus (Juncaceae)

Details of Carex hirta (Cyperaceae): stem with leaf sheaths (left); pistillate flowering spike (center); staminate flowering spike (right)

Photos of Schoenoplectus lacustris (Cyperaceae): base of shoot (left); longitudinally cut shoot (center); tip of shoot with flowering spikelets (right)

Scirpus silvaticus (Cyperaceae): entire inflorescence (left) and detail (right)

Fruiting spikes of Carex (Cyperaceae): C. pseudocyperus (left); C. riparia (right)

Infructescences of Eriophorum (Cyperaceae): E. angustifolium (left); E. vaginatum (right)

Flowering Plantaginaceae: Misopates orontium (left); Digitalis grandiflora (center); Globularia cordifolia (right)

Flower of Cymbalaria muralis: frontal view (left) and longitudinal section (right)

Fruits of Plantaginaceae: septicidal capsules in Digitalis purpurea (left), poricidal capsules in Antirrhinum majus (center), operculate capsules in Plantago lanceolata (right)

Aquatic plants in the Plantaginaceae: Hippuris vulgaris (left), Callitriche spec. (right)

Leaves of Apiaceae: Helosciadium nodiflorum (left), simply pinnate; Chaerophyllum bulbosum (right), multiply pinnate

Upper stem leaf of Angelica sylvestris (Apiaceae), with big leaf sheath

The typical compound umbel of Apiaceae (Laserpitium siler)

Details of Apiaceae inflorescences: first-order branching of the umbel in Conium maculatum (left), with involucral bracts; second-order branching = umbellule of Anthriscus sylvestris (right), with involucels

Flowers of Apiaceae: Caraway (Carum carvi, left); Dill (Anethum graveolens, right)

Fruits of Apiaceae, from left to right: Anthriscus sylvestris, Carum carvi, Angelica sylvestris, Scandix pecten-veneris

Leaves in Campanulaceae: almost linear in Campanula rotundifolia (left – the epithet rotundifolia refers to the basal rosett leaves only); cordate in Phyteuma spicatum (right)

Inflorescences in Campanulaceae: raceme in Campanula rapunculoides (left); spike in Phyteuma spicatum (center); head-like umbel in Jasione montana (right)

Flowers of Campanula persicifolia; lateral view (left) and frontal view (right); stamens already wilted before opening of the flower

Flower of Lobelia erinus, frontal and lateral view

Capsules in Campanulaceae: Campanula persicifolia (left), with distal pores in upright capsules; C. rapunculoides (right), with proximal pores in pendent capsules

Leaves of Asteraceae: Scorzonera hispanica (left); Achillea millefolium (center); Cirsium dissectum (right)

Capitula of Asteraceae: Cichorium intybus (left), with ray florets only; Tripleurospermum maritimum (center), with ray florets and disk florets; Cirsium oleraceum (right), with disk florets only

Closeup of the rim of a capitulum of Helianthus annuus (Asteraceae); spreading stigma branches visible in some florets in the foreground

Longitudinal section of a capitulum of Leucanthemum vulgare (Asteraceae)

Florets of Leucanthemum vulgare: ray floret(left) and two disk florets, in male phase (center) and in female phase (right)

Fruiting capitulum of Senecio inaequidens (Asteraceae)

Common Hazelnut (Corylus avellana): inflorescences (left), mainly staminate catkins, plus one pistillate flower (at the upper margin); young shoot (center), with glandular trichomes; branch with immature fruit (right)

Crataegus monogyna: flowers (left); leaf with axillary spine (right)

Impatiens parviflora flower: frontal view (left) and lateral view (right)

Alnus glutinosa fen wood near Prisdorf, Germany

Branch with inflorescences of the common oak (Quercus robur)

 Hypericum perforatum leaf, backlight

Wood-sorrel (Oxalis acetosella)

On the big dune in the nature reserve Boberger Düne, Hamburg, Germany

Deciduous forest with rich undergrowth near Prisdorf, Germany

Herb-Paris (Paris quadrifolia), one of the few monocotyledons with net-veined leaves

Heathland in the Boberger Düne nature reserve, Hamburg, Germany

Nature reserve Schnakenmoor, Hamburg, Germany

Immature fruits of Galium aparine

Chickweed (Stellaria media): shoot tip with flower (left); shoot with the typical unilateral pubescence (right)

Campanula barbata

Gaißbergferner

Gentiana clusii

Geum reptans

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Blick von der Hohen Muth auf Gaißbergtal (links) und Rotmoostal (rechts)

Kalmia procumbens

Linaria alpina

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Ranunculus glacialis

Rhododendron ferrugineum

Blick durch das Rotmoostal Richtung Rotmoosferner

Saxifraga oppositifolia

Participants of the field course in 2015

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Blick zum Wasserferner

Zirbenwald (Pinus cembra)

Flowering cushion of Androsace alpina

Thermocyclers in our PCR lab

Screenshot of an alignment of DNA sequences with chromatograms

Part of a phylogenetic tree (phylogram)

The ABI 3500 capillary sequencer in our sequencing lab

Myristica fatua as example of Myristicaceae, a pantropical tree family

Seedlings of the common beech (Fagus sylvatica), the most competitive tree in Central Europe on (moderately) fertile, neither too dry nor too wet soils

Views of the interior of Canarian laurel forest; Anaga mountains, Tenerife

View of a cloud forest (on an exceptionally clear day); Mt. Kaala, Oahu, Hawaii

Melocactus violaceus as example of Cactaceae, one of the typical plant families of the Neotropical floristic realm

Eucalyptus globulus as example of one of the most important genera of the Australian flora

Banksia integrifolia (Proteaceae) as example of a typical genus of Australian sclerophyll forest

Hymenophyllum recurvum as example of Hymenophyllaceae, a typical family of (sub)tropical cloud forests; insert: sorus

Silene acaulis as example of an arctic-alpine species with almost circumpolar distribution

Desert with salt succulent plants, mainly Chenopodiaceae; Chott el Gharsa, Tunisia

Schima argentea as example of Theaceae, one of the typical families of Asian laurel forests

Mt. Kinabalu in early morning light; Sabah, Malaysia

Uvaria macrophylla as example of Annonaceae, one of the large pantropical woody families

Darmera peltata as example of Saxifragaceae, one of the typical holarctic plant families: inflorescence (left); leaves (right)

Vantanea minor (Humiriaceae, left) and Stegolepis spec. (Rapateaceae, right), as examples of two of the typical plant families of the Venezuelan-Guayanian floristic region

Araucaria angustifolia forest, with laurel forest as second canopy stratum; near São Francisco de Paula, Rio Grande do Sul, Brazil

Saxifraga aizoides (left) and S. oppositifolia (right), two arctic Saxifraga species

View of the Gran Sabana, Venezuela

Bushland on white sand; near Linhares, Espírito Santo, Brazil

Tree savanna (campo cerrado) near Rio Claro, São Paulo, Brazil

Coastal redwood (Sequoia sempervirens): bole (left); tip of branch with young staminate cones (right)

Tropical seasonal forest near Caracas, Venezuela: dry season (left); same spot four weeks later after onset of the rainy season (right)

Rhamnus californica (Rhamnaceae) as example of one of the typical families of sclerophyll forests

Fraxinus angustifolia as example of one of the charakteristic genera of northern temperate deciduous forests

Braunsia apiculata as example of Aizoaceae, one of the typical plant families of the Cape floristic realm

Mangrove vegetation, predominantly consisting of Sonneratia alba; near Cooktown, Queensland, Australia

Nyssa as example of a genus disjunct between East Asia and eastern North America: N. sylvatica from North America (left); N. sinensis from China (right)

Raoulia subsericea (Asteraceae), a hard cushion plant from alpine New Zealand

Pinus banksiana (left) and Picea glauca (right), two of the typical conifers of boreal North America

Impatiens,  one of the typical genera in the undergrowth of palaeotropical montane forests: I. arguta (left); I. kilimanjari (right)

Maytenus ilicifolia (Celastraceae) as example for one of the typical genera of laurel forests

Lychnophora spec. in a tropical upland savanna (campo rupestre); Serra do Cipó, Minas Gerais, Brazil

Tillandsia strica as example of Bromeliaceae, one of the typical plant families of the Neotropical floristic realm

Sanguinaria canadensis (Papaveraceae) from North America as example of an early blooming plant in temperate deciduous forests

Subtropical alpine vegetation, Cañadas del Teide, Tenerife

Alpine tundra above Obergurgl, Austria

Linnaea borealis, a species with circumpolar distribution in the boreal zone

Cedrus deodara, branch with staminate cones, as example of the characteristic genus of nemoral coniferous forests of the Old World

Tropical rainforest in morning mist; Citalahab, Java, Indonesia

Remnant of tidal riparian forest on the river Krückau near Elmshorn, Germany

Alnus incana as example of Betulaceae, one of the typical holarctic plant families: staminate catkins (left); leaf (center); pistillate catkins (right)

Dryas octopetala, one of the most characteristic species of tundra vegetation

Fallen fruits of Elaeocarpus angustifolius, one of the typical species of Australian laurel forests

View of the laurel forest at the Rota do Sol, Rio Grande do Sul, Brazil

Some representatives of Dipterocarpaceae, the most important tree family in tropical and subtropical Asia: fruit of Dipterocarpus zeylanicus (left); habit of Parashorea chinensis (center); fruit of Shorea spec. (right)

Dampiera diversifolia as example of Goodeniaceae, one of the typical families of the Australian floristic realm

Metrosideros polymorpha (Myrtaceae), the originally dominant tree species in Hawaii, before the introduction of alien competitors

Euphorbia balsamifera as example of one of the typical genera of (semi-)arid regions of the Old World; in the dry season (left) and in the rainy season (right)

Inundated white sand savanna at the border between Venezuela and Colombia

Grevillea coriacea (Proteaceae) in subhumid forest; Spear Creek, Queensland, Australia

Tamarix sp. in a sandy desert in Tunisia

Light microscope photo of a cross section of a leaf of  Ruellia makoyana

Allium cepa, root tip, longitudinal section

Light microscope photo of glandular hairs on the upper leaf surface of Salvia

Light microscope photo of a cross section of a stem of Tradescantia, outer layers, with plate collenchyma and a stoma

Light microscope photo of a cross section of the aerial root of an orchid (Encyclia spec.), central cylinder, stained with phloroglucin/HCl; endodermis and xylem red, cortex parenchyma, passage cells and phloem unstained

Ranunculus repens, young root, cross section

Photos of germinated maize grains (Zea mays): basal part (left), primary root still preserved, with secondary roots; different stages of germination (center); tip of coleoptile perforated by the primary leaf (right)

Aristolochia macrophylla, young stem, cross section, with incipient development of an intervascular cambium

Zea mays, stem, cross section, outer layers with closed collateral vascular bundles