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4521 results in Botanical reference

Page 22 of 227

  • Division 5 - Magnoliophyta

  • from Kingdom 1 - Plantae
  • Peter Sell, University of Cambridge, Gina Murrell, University of Cambridge
  • Book:
    Flora of Great Britain and Ireland
    Print publication:
    12 April 2018, pp 116-124

  • Summary

    Vascular plants, normally with roots, stems and leaves; central cylinder of the stems with leaf-gaps or vascular bundles; xylem usually but not always consisting in part of vessels; phloem with definitive sieve-tubes and companion-cells. Perianth usually consisting of an outer set of members, the sepals, forming a calyx, and an inner set, the petals, forming a corolla; androecium consisting of one to many stamens and gynoecium consisting of one to many carpels, either in the same flower or separately on the same plant (monoecious) or on different plants (dioecious).

  • Plants free-floating on or below the surface of the water, not rooted in mud 2.

  • Land plants or aquatics rooted in mud 7.

  • Plants without obvious differentiation into stems and leaves 162. LEMNACEAE

  • Plants with obvious stems and leaves 3.

  • Leaves divided into numerous filiform segments 4.

  • Leaves not divided into numerous filiform segments 6.

  • Plants with small bladders on leaves or on apparently leafless stems 141. LENTIBULARIACEAE

  • Plants without small bladders 5.

  • Leaves dichotomously divided, the segments often again divided 31. CERATOPHYLLACEAE

  • Leaves pinnately divided, the segments simple 90. HALORAGACEAE

  • Perianth with a distinct calyx and corolla; petioles not inflated 151. HYDROCHARITACEAE

  • Perianth entirely petaloid; basal part of petioles inflated 171. PONTEDERIACEAE

  • Aquatic with rooted submerged stems (though often found detached and floating); submerged leaves in opposite pairs, petiolate; lamina initially palmately branched and then dichotomously or ternately divided into linear segments, forming a broad fan; floating leaves and flowers not found in the wild in Britain 30A. CABOMBACEAE

  • Not as above 8.

  • 2- to 4-fid coloured staminodes present; leaves often fasciculate 52. CARYOPHYLLACEAE

  • Not as above 9.

  • Perianth absent, or of a single whorl, or of 2 or more whorls, all similar in shape, size, colour and texture 10.

  • 62 - Cistaceae

  • from Division 5 - Magnoliophyta
  • Peter Sell, University of Cambridge, Gina Murrell, University of Cambridge
  • Book:
    Flora of Great Britain and Ireland
    Print publication:
    12 April 2018, pp 591-594

  • Summary

    Annuals or evergreen, woody, dwarf perennials. Leaves opposite at least below, entire, with or without stipules. Inflorescence a simple terminal cyme; flowers actinomorphic, bisexual, hypogynous. Sepals 5, the outer 2 smaller than the inner 3 except in Cistus, or 3 only. Petals 5, predominantly yellow or white. Stamens numerous. Style 1 or absent; stigma 1, but 3-lobed or 5-lobed in Cistus, or stigmas 3. Ovary 1-celled, with many ovules on 3 placentae (5-celled in Cistus). Fruit a capsule with 3 or 5 valves.

    Contains 7 genera and about 180 species. Native to temperate areas and especially the Mediterranean.

  • Capsules with 5, 6 or 10 valves; flowers white to purplish-red 3. Cistus

  • Capsules with 3 valves; flowers white, pink or yellow 2.

  • Annuals or perennials, with basal leaf-rosette or a woody stock; style very short or absent 1. Tuberaria

  • Woody perennials; style at least as long as the ovary 2. Helianthemum

    • Tuberaria (Dunal) Spach

    Helianthemum sect. Tuberaria Dunal

    Annual or perennial herbs with basal leaf-rosette or a woody stock. Leaves opposite, entire. Inflorescence a cyme. Sepals 5. Petals 5. Stamens numerous. Stigma more or less sessile. Fruit a capsule.

    Contains 12 species, mainly from central and south Europe.

  • Perennial; flowers about 3 mm wide; petals without a dark spot at base 2. lignosa

  • Annual; flowers 8–20 mm wide; petals usually with a dark spot at base 2.

  • Stem up to 30 cm, erect; upper leaves with stipules, scarcely narrower than lower; inflorescence with bracts 1(a). guttata subsp. guttata

  • Stem up to 10 cm, spreading; upper leaves without stipules, narrower than lower; inflorescence without bracts 1(b). guttata subsp. breweri

    • T. guttata (L.) Fourr. Spotted Rock-rose Cistus guttatus L.; Helianthemum guttatum (L.) Mill.

    Annual herb. Stems up to 30 cm, pale green, more or less procumbent to erect, with stellate and simple eglandular hairs. Leaves medium green, 3-veined; basal forming a rosette, usually dead at anthesis; lower cauline opposite, with lamina 1.5–5.0 cm, elliptical-lanceolate, subacute at apex, entire; upper cauline alternate, shorter and narrower, linear-oblong or linear-lanceolate, more or less revolute, with conspicuous linear stipules; all with stellate hairs on both surfaces or only simple eglandular hairs on upper surface.

  • 17 - Woodsiaceae

  • from Division 3 - Polypodiophyta
  • Peter Sell, University of Cambridge, Gina Murrell, University of Cambridge
  • Book:
    Flora of Great Britain and Ireland
    Print publication:
    12 April 2018, pp 32-38

  • Summary

    Perennial herbs with short, rarely long rhizomes. Fronds borne in tufts at the end of rhizomes or sometimes singly at intervals, spirally coiled when young, with scales of 1 or 2 kinds, fertile and sterile, 1- to 4-pinnate; stipe grooved, with 2 vascular bundles which unite distally into a single strand. Sori variable. Indusia present or absent. Plants homosporous. Gametophyte green, surface-living.

  • Fertile fronds very different from the sterile ones 2.

  • Fertile and sterile fronds similar 3.

  • Lamina of sterile fronds oblanceolate, bipinnate 1. Matteuccia

  • Lamina of fronds triangular, pinnate 2. Onoclea

  • Rhachis jointed below the middle; indusia cup-shaped, fringed with long jointed hairs 6. Woodsia

  • Rhachis not jointed; indusia different from last or absent 4.

  • Fronds tufted; lamina lanceolate or oblanceolate 5.

  • Fronds single, from an elongated rhizome; lamina more or less triangular 6.

  • Sori elongated or suborbicular (if so without indusium); fairly large plants, usually growing on soil 3. Athyrium

  • Sori orbicular, with indusium at least when young; small plants, usually growing in rock fissures or on walls 5. Cystopteris

  • Pinnules entire or finely serrate; indusia absent 4. Gymnocarpium

  • Proximal pinnules pinnate; sori when young with bowlshaped indusium 5. Cystopteris

  • 14 - Dennstaedtiaceae

  • from Division 3 - Polypodiophyta
  • Peter Sell, University of Cambridge, Gina Murrell, University of Cambridge
  • Book:
    Flora of Great Britain and Ireland
    Print publication:
    12 April 2018, pp 24-26

  • Summary

    Perennial herbs with deeply subterranean, very extensive, hairy rhizomes, but without scales. Fronds borne singly, spirally coiled when young, of one kind, (2–)3-pinnate, with strong long stem-like stipe and rhachis; lower pinnae often remote. Sori marginal, more or less continuous, enfolded by reflexed margin of the pinnule. Plants homosporous. Gametophyte green, surface-living.

  • 55 - Paeoniaceae

  • from Division 5 - Magnoliophyta
  • Peter Sell, University of Cambridge, Gina Murrell, University of Cambridge
  • Book:
    Flora of Great Britain and Ireland
    Print publication:
    12 April 2018, pp 559-560

  • Summary

    Perennial herbs with fleshy roots or soft-wooded shrubs

    Leaves alternate, compound, at least the lower ones. Flowers bisexual, radially symmetric, large, solitary and terminal; floral bracts 1–12, leafy, immediately below calyx. Sepals 5, free, persistent, unequal. Petals 5–10, free. Stamens numerous; anthers opening by longitudinal slits. Carpels 1–8, free on a fleshy disc; ovules numerous, lateral, in 2 rows. Fruit of 1–5 diverging follicles, each with several seeds, opening by a slit on the upper side; seeds large.

    Contains one genus.

    Paeonia L.

    Perennial herbs, usually with woody stems, dying down in winter or evergreen, with erect, tuberous stocks and fleshy roots. Leaves large, alternate, biternate or further divided. Flowers large. Sepals 5. Petals 5–10 (except in double-flowered cultivars), free, white or red. Stamens numerous. Fruit of 1–5 follicles; seeds in 2 rows.

    Contains about 30 species in southern Europe, northwest Africa, northern Asia from Caucasus to Japan and western North America.

    Melville, R. (1983). The affinity of Paeonia. Kew Bull. 38 : 87–105.

    Stern, F. C. (1946). A study of the Genus Paeonia. London.

  • Lower leaves divided into 25 or more divisions, usually themselves lobed 3. officinalis

  • Lower leaves divided to axis into 9–23 distinct leaflets 2.

  • Flower stems always with one flower 1. mascula

  • Flower stems with two or more flowers 2. lactiflora 1. P. mascula (L.) Mill. Peony P. officinalis var. mascula L.; P. corallina Retz.; P. decora auct.

    • Perennial herb with thick, carrot-like, woody roots. Stems 30–60 cm, pale green, tinted rose or purplish-red, arising from 4–7, lingulate, chartaceous, purplish basal sheaths 1–7 × 1.0–1.5 cm, distinctively sulcate, erect, glabrous or hairy. Leaves 4–7 in a clump; lamina 20–25 × 20–25 cm, bright green, tinged purple or pink, broadly ovate in outline, irregularly ternate or biternate, the ultimate segments 12–21, 6–14 × 2.5–7.0 cm, elliptical, oblong, or elliptical-lanceolate, often distinctly asymmetrical, acute at apex, entire, the petiolules up to 11 cm, the petiole 5–12 cm, all glabrous. Flowers solitary per stem, shallowly cup-shaped, 6.5–14 cm in diameter, sweetly scented; peduncle 3–12 cm.

  • Foreword

  • Peter Sell, University of Cambridge, Gina Murrell, University of Cambridge
  • Book:
    Flora of Great Britain and Ireland
    Print publication:
    12 April 2018, pp ix-x

  • Summary

    VOLUME 5

    It has been one of the continuing satisfactions of my academic career in Cambridge that the University Herbarium, of which I was Curator from 1948 to 1973, has provided an academic base for all my specialist interest in Angiosperm taxonomy to develop. Indeed, I count myself doubly fortunate that, twelve years after my retirement from academic life, the Herbarium, with its staff and visitors, still provides such a base where scholarship can be pursued for its own sake. With great pleasure I welcome this volume, the first of a set of five promised to us by Peter Sell and Gina Murrell. My association with Peter goes back more than half a century: though I was ‘senior partner’ in our happy collaboration in the post-war Herbarium, ours was a symbiotic relationship from which we both greatly benefited, and I was delighted when Gina, who had been part of the team in the 1960s and 1970s, returned to the fold as Herbarium Technician in 1991.

    As explained in the Preface, this project to write an entirely new critical flora of Great Britain and Ireland comes to fruition some twenty years after an earlier scheme, in which the late Professor David Valentine took a leading part, had failed to find any financial support. Both Clive Stace, to whose New Flora of the British Isles (1991) Peter pays tribute in the Preface, and Peter himself, were enthusiastic supporters of the Valentine project, and were prepared to play major parts in writing the Flora. It is fitting that both these eminent British taxonomists should separately carry on the tradition that David Valentine so enthusiastically advocated.

    Two aspects of this new critical flora seem to be especially important. One concerns the acceptance, long overdue, of the ‘alien element’ in our flora as being equally worthy of taxonomic study: in this respect Stace's Flora represents a real change in attitude, which is to my mind unreservedly to be welcomed. The other, interestingly linked to the first by many examples, concerns the taxonomic recognition and treatment of hybrids and infraspecific variants.

  • Division 2 - Equisetophyta

  • from Kingdom 1 - Plantae
  • Peter Sell, University of Cambridge, Gina Murrell, University of Cambridge
  • Book:
    Flora of Great Britain and Ireland
    Print publication:
    12 April 2018, pp 7-7

  • Summary

    Rhizomatous perennial herbs with aerial stems elongated, jointed, simple or bearing whorls of branches at the nodes. Leaves borne in whorls and fused into a sheath around the stem, simple, with 1 vein. Sporangia homosporous, borne in clusters under peltate, specialised branches which are arranged in terminal cones. Gametophytes free-living, green and photosynthetic.

  • 19 - Dryopteridaceae

  • from Division 3 - Polypodiophyta
  • Peter Sell, University of Cambridge, Gina Murrell, University of Cambridge
  • Book:
    Flora of Great Britain and Ireland
    Print publication:
    12 April 2018, pp 38-49

  • Summary

    Perennial herbs with short erect or ascending rhizomes with densely opaque scales. Fronds borne in tufts at end of rhizome or its branches, spirally coiled when young, with scales, usually of one kind, 1–3(–4) pinnate. Sori circular, on underside of frond. Indusia peltate or reniform. Plants homosporous. Gametophyte green, surface-living.

  • Fronds simple or 1-pinnate with pinnae entire to toothed less than halfway to midrib 2.

  • Fronds 1-pinnate with pinnae divided more than halfway to midrib 3.

  • Pinnae less than 1.5 cm broad, with sori in one row either side of midrib 1. Polystichum

  • Pinnae more than 1.5 cm broad, with sori distributed more or less evenly all over underside 2. Cyrtomium

  • Pinnules with teeth contracted into a very fine acuminate apex; indusia peltate 1. Polystichum

  • Pinnules untoothed or with rounded to acute teeth; indusia absent, vestigial or reniform 3. Dryopteris

    • Polystichum Roth

    Perennial herbs with stout erect or ascending rhizomes. Fronds in tufts at ends of or on branches of rhizomes, of one kind, 1–2-pinnate, often coriaceous; pinnae and pinnules asymmetrical, with teeth with an apical bristle or spine. Sori in a row down each side of pinna or pinnules or sometimes of main lobes of pinnules. Indusia peltate, attached at the centre.

  • 6 - Osmundaceae

  • from Division 3 - Polypodiophyta
  • Peter Sell, University of Cambridge, Gina Murrell, University of Cambridge
  • Book:
    Flora of Great Britain and Ireland
    Print publication:
    12 April 2018, pp 16-16

  • Summary

    Perennial herbs with a large, more or less erect, scaleless rhizome. Stipes bearing both a sterile and a fertile lamina. Sterile laminas pinnate, with broad pinnae. Fertile laminas pinnate, with the narrow pinnae covered with dense clusters of sporangia, the whole forming a tassel-like apex to the frond. Sporangia marginal or superficial, all alike and developing simultaneously, dehiscing by a slit. Indusia absent. Annulus consisting of a group of thick-walled cells near the apex. Spores numerous, green. Prothallus green, cordate, fleshy, surface-living.

    Contains three genera and about 19 species, cosmopolitan.

  • Division 3 - Polypodiophyta

  • from Kingdom 1 - Plantae
  • Peter Sell, University of Cambridge, Gina Murrell, University of Cambridge
  • Book:
    Flora of Great Britain and Ireland
    Print publication:
    12 April 2018, pp 13-14

  • Summary

    Perennial (rarely annual) herbs, and some trees, with alternation of generations physiologically independent of each other at maturity. Sporophyte well developed, ordinarily differentiated into roots, stipe (stem) and frond (leaf), forming the phase of the life cycle that is usually seen. Stipe unbranched or more often dichotomously to monopodially branched, not producing dormant axillary buds, though the branches are sometimes axillary. Fronds mostly alternate, usually large and compound or cleft and with a branching vascular system, or sometimes much reduced. Sporangia borne on vegetative or modified fronds, often at the margins or on the underside, or sometimes in specialised sporocarps which represent modified frond segments or enlarged indusia. Sporophylls never aggregated into a terminal strobilus (cone). Gametophyte small, photosynthetic or less often mycorrhizal or depending on its stored food.

    Contains 38 families. In this division species are being continually moved from one genus to another, but the large number of synonyms given will enable users to adopt whichever name they prefer.

  • 40 - Urticaceae

  • from Division 5 - Magnoliophyta
  • Peter Sell, University of Cambridge, Gina Murrell, University of Cambridge
  • Book:
    Flora of Great Britain and Ireland
    Print publication:
    12 April 2018, pp 310-314

  • Summary

    Annual to perennial herbs. Leaves opposite or alternate, simple; stipules often present. Flowers axillary, usually small and inconspicuous, solitary or in crowded cymes, monoecious or dioecious, unisexual or bisexual, hypogynous, actinomorphic. Perianth segments of one whorl of 4, often partly fused at base, greenish or brownish. Male flowers with 4 stamens, inserted opposite the perianth segments, rudimentary ovary often present; anthers 2-celled, opening lengthwise. Female flowers with a 1-celled ovary with 1 ovule; style 1, the stigma much-branched; fruit an achene, the seed usually with endosperm.

    Consists of about 45 genera and over 700 species, mostly in the tropics or subtropics with a few species in cooler parts of the world.

  • Leaves opposite, usually toothed, often with stinging hairs, with stipules 1. Urtica

  • Leaves alternate, entire, without stinging hairs, without stipules 2.

  • Stems erect or decumbent but not rooting at the nodes; leaves mostly more than 10 mm; flowers crowded 2. Parietaria

  • Stems procumbent and rooting at the nodes; leaves rarely more than 6 mm; flowers solitary 3. Soleirolia

    • Urtica L.

    Annual or perennial, monoecious or dioecious, unisexual or bisexual herbs, mostly with stinging hairs. Stems erect, ridged or 4-angled. Leaves opposite, toothed, with free stipules. Inflorescence axillary, spike-like, with clustered cymes. Perianth segments 4, free; female flowers with the 2 inner longer than the 2 outer and enclosing the fruit. Stamens 4. Style 1; stigma much-branched. Fruit an achene.

    Contains about 50 species in temperate regions. In the past nettles have had a large number of useful attributes. The Romans certainly ate nettles and on our Celtic fringe nettles have been traditionally eaten with oatmeal in a soup, while ‘St Columba's broth’ tastes remarkably like soup made from young peas. The young tops can be used as a green vegetable, usually in the form of a purée like spinach, but they have an earthy flavour. In Scotland nettle pudding was made with leeks and onions, broccoli or cabbage with rice, boiled in a muslin bag and served with butter and gravy. During the Second World War schools collected great quantities of nettles for medicinal use. Painful joints were formally stung with nettles to warm the joint and relieve the pain of arthritis.

  • 41 - Juglandaceae

  • from Division 5 - Magnoliophyta
  • Peter Sell, University of Cambridge, Gina Murrell, University of Cambridge
  • Book:
    Flora of Great Britain and Ireland
    Print publication:
    12 April 2018, pp 314-317

  • Summary

    Deciduous, monoecious trees. Leaves alternate, imparipinnate, without stipules. Flowers unisexual, epigynous, more or less actinomorphic. Male flowers in pedunculate catkins; bracteoles 2, rarely absent; perianth absent or small and 1- to 5-lobed; stamens 3 to many; filaments short; a rudimentary ovary sometimes present. Female flowers in pendulous catkins or one to few in a stiff cluster, in the axil of a bract; bracteoles 2; perianth small and inconspicuous, 1- to 5-lobed; styles 2; stigmas branched; ovary 1-celled, with 1 ovule. Fruit a drupe or winged nut; seeds without endosperm.

    Contains about seven genera and over 60 species in the northern hemisphere, in temperate areas and on mountains in the tropics, and in South America.

  • Pith continuous; male catkins 3 or more together; perianth of male flowers absent or very small 2. Carya

  • Pith chambered; male catkins solitary; perianth of male flowers present 2.

  • Buds sessile, with scales; leaves aromatic; fruit a large drupe 1. Juglans

  • Buds stipitate, usually naked; leaves not aromatic; fruit a winged nut 3. Pterocarya

    • Juglans L.

    Deciduous, monoecious trees. Twigs with chambered pith. Buds with scales, sessile. Leaves alternate, imparipinnate, aromatic. Flowers unisexual. Male flowers numerous, in solitary pendulous catkins; bracteoles 2; perianth absent or small and 1–5-lobed; stamens 4–40; filaments short; a rudimentary ovary sometimes present. Female flowers in erect terminal few-flowered spikes; bracteoles 2; perianth 4-lobed; stigmas 2, simple. Fruit a large indehiscent drupe; stone (walnut) incompletely 2- to 4-celled.

    Contains about 15 species in north temperate regions, south-east Asia, Jamaica and Central and South America.

  • 10 - Hymenophyllaceae

  • from Division 3 - Polypodiophyta
  • Peter Sell, University of Cambridge, Gina Murrell, University of Cambridge
  • Book:
    Flora of Great Britain and Ireland
    Print publication:
    12 April 2018, pp 20-21

  • Summary

    Perennial herbs with thin, glabrous or hairy, creeping rhizomes. Fronds borne singly along the rhizomes, spirally coiled when young, thin and translucent, of one kind, 1- to 3-pinnate. Sori marginal on the vein endings, often projecting from the lamina. Indusia more or less cup-like, entire or 2-lipped or 2-valved, surrounding the base or the whole of the sorus. Sporangia all alike, shortly stalked, developed successively from apex to base; annulus oblique, without a definite stomium, the sporangia opening laterally by a long slit. Spores 32–420, homosporous. Gametophyte green, surface-living, either filamentous or strap-like.

    Contains 34 genera and about 600 species; mostly tropical, a few in moist parts of the temperate zones; absent from dry areas.

  • 21 - Azollaceae

  • from Division 3 - Polypodiophyta
  • Peter Sell, University of Cambridge, Gina Murrell, University of Cambridge
  • Book:
    Flora of Great Britain and Ireland
    Print publication:
    12 April 2018, pp 50-51

  • Summary

    Plants small, free-floating, with hanging simple roots, without scales. Stems very slender and branching. Fronds alternate, 2-ranked, imbricate, 2-lobed, the upper lobe floating, green, with a hollow filled with mucilage and containing the threads of the cyanobacterium Anabaena azollae Strasb., the lower lobe thin, submerged and bearing the globose sori called sporocarps in pairs on cylindrical receptacles. Sporocarps consisting of either numerous microsporangia developed successively from the apex to the base, each consisting of 64 microspores, or of a single megasporangium containing a single megaspore. The microsporangia produce the mobile male gametes. These fertilise the megaspores in the larger sporocarps. After fertilisation the embryo develops within the wall of the megaspore until the first frond grows, when it emerges as a free-floating sporophyte.

    Contains only one genus.

    The presence of the nitrogen-fixing Anabaena has led to the use of Azolla in east Asia as a food for livestock and a green manure for rice fields. It is a practice which originated in China at least 2000 years ago.

  • 4 - Equisetaceae

  • from Division 2 - Equisetophyta
  • Peter Sell, University of Cambridge, Gina Murrell, University of Cambridge
  • Book:
    Flora of Great Britain and Ireland
    Print publication:
    12 April 2018, pp 7-12

  • Summary

    Perennial herbs with creeping rhizomes, bearing aerial stems at intervals. Stems all green or the fertile stems without chlorophyll, all grooved, simple or branched from near the base, with the branches resembling the stems or with whorls of slender green branches from the nodes, with a central cavity surrounded by two circles of smaller cavities, the larger, outer ones called vallecular canals. Leaves in whorls, united into sheaths above the nodes, the sheaths ending in free teeth usually of the same number as the grooves on the stem, usually not green; sheaths of branches much smaller with fewer teeth. Sporangiophores in whorls, closely aggregated to form a spike or cone, usually terminal on the main stem and occasionally also on the branches. Spores all alike, numerous in sporangia borne in groups around the under surface of the sporangiophore. Archegonia and antheridia borne on separate gametophytes, the female being larger. Gametophytes with a cushion-like base bearing green flat lobed structures arising from the under surface, with the sex organs borne on the upper surface of the cushion. Spermatozoids multiciliate.

  • 23 - Taxodiaceae

  • from Division 4 - Pinophyta
  • Peter Sell, University of Cambridge, Gina Murrell, University of Cambridge
  • Book:
    Flora of Great Britain and Ireland
    Print publication:
    12 April 2018, pp 95-99

  • Summary

    Monoecious, resinous trees or shrubs, usually evergreen, sometimes deciduous. Leaves usually spirally arranged, sometimes slightly 2- to 5-ranked, linear, linear-oblong or subulate. Male strobili rather small, catkin-like, usually in clustered groups; microsporophylls with 2–9 microsporangia; pollen grains wingless and lacking air-bladders. Cones mainly more or less globose or ovoid, usually maturing in 1 year, relatively small; scales several to many, spirally arranged, woody, more or less fused with the bracts, each bearing 2 or more inverted ovules. Seeds often with a narrow even wing on each side. Cotyledons 2–15.

    Contains about 16 species in 9 genera, 7 of which are monotypic. Mainly in China and Japan, extending to Taiwan and north-east Burma; also in the eastern U.S.A. and Mexico, with an isolated genus in western Tasmania. Many of the species are planted elsewhere for ornament and occasionally timber.

  • 13 - Dicksoniaceae

  • from Division 3 - Polypodiophyta
  • Peter Sell, University of Cambridge, Gina Murrell, University of Cambridge
  • Book:
    Flora of Great Britain and Ireland
    Print publication:
    12 April 2018, pp 23-24

  • Summary

    Terrestrial ferns. Rhizome forming a single arborescent trunk, without scales, hairy. Lamina 1–4 pinnate; venation free, forked. Sori borne on segment margins at the end of veins. Sporangia enclosed by a membranous inner indusium and small reflexed lamina lobes. Spores trilete.

    Contains about 5 genera and around 50 species.

    Dicksonia L'Hér.

    Tree-like terrestrial ferns with a thick or thin rhizome covered with matted growths of old stipe bases, bristly hairs and interwoven roots which build up the bulk of the girth and with dense masses of rust-brown hairs among the crown. Fronds spreading regularly from the crown, all of one kind, evergreen; lamina often slightly prickly. Sori marginal on pinnules, each protected by a 2-lobed indusium, and on the outer portion of the reflexed margin of the pinnule.

    Contains about 25 species in Australasia, Polynesia and Mexico. They are long-lived and moderately slow-growing.

  • 8 - Pteridaceae

  • from Division 3 - Polypodiophyta
  • Peter Sell, University of Cambridge, Gina Murrell, University of Cambridge
  • Book:
    Flora of Great Britain and Ireland
    Print publication:
    12 April 2018, pp 18-19

  • Summary

    Perennial herbs with short scaly rhizomes. Fronds tufted at apices of rhizome branches, spirally coiled when young, more or less of one kind but those bearing sori with narrower segments, 1- to 4-pinnate, with the basal pinna on each side sometimes bearing another pinna near its base. Sori linear, along margins of fronds, protected by reflexed lamina edge. Sporangia homosporous. Indusia absent. Prothallus green, surface-living.

    Contains 6 genera with a worldwide distribution.

Page 22 of 227