Download Education: Some horticulturally important plant families

Magnoliaceae
Trees or shrubs; leaves simple or lobed, sometimes evergreen, spirally arranged with well-defined
stipules protecting the bud; flowers solitary, large, radially symmetrical, mostly bisexual, the calyx
3, petaloid and not differentiated from the 6-18 petals arranged in two or more whorls; stamens
many, often flattened and petal-like with 4 pairs of microsporangia (Anthers) embedded on or in
the surface; ovary superior, the carpels many and often spirally arranged, the stigma terminal or
sometimes marginal on each carpel, the ovules 2 or more per locule; fruits a follicle or an
indehiscent capsule, forming a samaroid in Liriodendron; seeds large and occasionally highly
coloured and suspended from the fruit by a funiculus,
13 genera, 225 species. Widespread in tropical and warm temperate regions, especially in North
America and southeastern Asia.
Both Magnolia and Liriodendron exhibit the southeastern North America - Eastern Asia
distribution pattern probably due to the Ice Ages.
PALEO HERBS
Perhaps no more fundamental contribution has been made by the molecular systematists over the
last 15 years than the discovery that the division of angiosperms into dicotyledons and
monocotyledons is not a simple evolutionary story. The key to this revelation are primitive dicot
families such as Piperaceae, Aristolochiaceae and Nymphaceae.
The significance of the paleoherbs in the evolutionary scheme an be expressed in the "sneaky herb
hypothesis." This maintains that the earliest angiospermous plants that arose in pre-Cretaceous
times differentiated rapidly into three major lines. The first, represented by the magnolian
angiosperms, were basically arborescent edge-dwellers. The second, represented by the piperoid
angiosperms, were basically herbaceous forest-dwellers. The third, represented by the
nymphaeoid/nelumbonoid and the monocotyledonous angiosperms, were aquatic or near-aquatic
dwellers. Accordingly, the herbaceous members were exceedingly diverse and evolutionarily
dynamic while the magnolian element was basically a dead-end group.
The most dynamic of the "sneaky herbs" was the line that likely came from the same basal group
that gave rise to all of the modern angiosperms, and these are the Ranunculaceae. As a group of
herbs, they represented sufficient variation and the potential for rapid evolution to be the source of
all the remaining dicotyledonous angiosperms.
Nymphaceae (Waterlily flower) showing gradation from green sepals to white petals, and a
second gradation from petal through to stamen.
SOME HORTICULTURALLY IMPORTANT FLOWERING PLANT FAMILIES
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Ranunculaceae
Shrubs, lianas (Clematis) and herbs, infrequently aquatic; leaves simple (entire to dissected) or
compound (pinnate or palmate) and then usually 3-parted, alternate and spirally arranged,
opposite in Clematis; flowers small to mid-size, occasionally unisexual as in Thalictrum, solitary
or more commonly in cymes, racemes or panicles, actinomorphic or zygomorphic, the calyx (3)
5-8 or numerous and typically petaloid, the corolla few to many, often highly coloured, often with
prominent nectaries, occasionally spurred; stamens numerous and spirally arranged, free; ovary
superior, the carpels (1) several to many, rarely slightly connate (Nigella) with axile placentation,
the ovules (1 in Actaea) several-many in each carpel, mostly marginal; fruits usually a follicle, an
achene or a berry, rarely a capsule (Aquilegia, Nigella). Cosmopolitan but mainly temperate
and boreal regions of the world. Approximately 60 genera and 2000 species.
Regular flowers: Pasque flower (Anemone, Pulsatilla), Hellebore, Ranunculus, Clematis
Irregular flowers: Larkspur (Delphinium), Monkshood (Aconitum) Columbine (Aquilegia)
Petals very reduced, ‘flowers’ of stamens only: Thalictrum, Cimicifuga or Actaea.
Many species of this family are poisonous.
Clematis
Ranunculus
Aquilegia
Nigella
SOME HORTICULTURALLY IMPORTANT FLOWERING PLANT FAMILIES
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Cactaceae
Succulent perennials herbs, climbers, shrubs and trees typically with spines in association with
hairy axillary buds (areoles); leaves mostly lacking, otherwise spirally arranged, simple, entire;
flowers solitary at the areoles or at the branch tips, infrequently in cymes or panicles, perfect or
rarely unisexual, regular or somewhat irregular, epigynous, the sepals numerous and spirally
arranged, the outer ones sepaloid (green/brown), the inner ones showy and petaloid, all connate
basally to form a tubular hypanthium; stamens numerous and arising from the hypanthium; ovary
inferior, the carpels 3-20 united to form an unilocular ovary with a long, solitary style terminated
by numerous, spreading stigmas, the ovules numerous and mostly parietal; fruits mainly a fleshy,
juicy, indehiscent berry, infrequently dry and dehiscent.
Arid regions in the New World with only one species of Rhipsalis widely distributed in Africa,
Madagascar and Sri Lanka .Those of arid regions are typically spiny whereas those from moist,
tropical regions tend to be spineless as well as epiphytic.
Crassulacean Acid Metabolism - CO2 absorption at night. Shallow, extensive roots
The generic problem: Conservatively, some accept only about 30 genera while other suggest the
number of genera is closer to 200. ca. 1600 species.
Many species are in cultivation to the point that many are internationally considered threatened
and endangered due to over collecting.
SOME HORTICULTURALLY IMPORTANT FLOWERING PLANT FAMILIES
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Caryophyllaceae
Annual or perennial herbs or subshrubs, rarely shrubs or small trees (unusual secondary
thickening) with stems often swollen at the nodes; leaves opposite, rarely seemingly whorled,
simple, entire; inflorescences typically cymose; flowers small to mid-size and occasionally showy,
actinomorphic, bisexual, 4-5-merous, the sepals (4) 5, rarely free or connate for most of their
length, the petals (4) 5, rarely more, showy and often bifid, free; stamens 5 or 10 in 2 whorls,
typically twice the number of petals, rarely fewer; ovary superior or rarely slightly inferior, the
carpels 2-5 (7-10) and united to form a compound ovary with as many locules as carpels and an
equal number of distinct or connate styles, the mostly numerous ovules arranged on the central
column in two rows; fruits a capsule, splitting into as many or twice as many valves or teeth as
carpels, occasionally an achene or even a dry berry, the numerous seeds mostly black.
About 90 genera and perhaps 2000 species. Cosmopolitan, especially in warm and temperate
regions in the Northern Hemisphere.
Numerous species are cultivated as ornamentals Agrostemma, Arenaria, Dianthus (the
carnation =D. caryophyllus), Gypsophila, Saponaria, and Silene.
SOME HORTICULTURALLY IMPORTANT FLOWERING PLANT FAMILIES
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Rosaceae
Evergreen or deciduous trees, shrubs and herbs; leaves alternate or rarely opposite, simple or
variously compound, entire to variously lobed, toothed or dissected, stipules usually present;
inflorescences typically arranged in cymes, occasionally solitary; flowers small to large, bisexual or
occasionally unisexual, actinomorphic or occasionally zygomorphic, perigynous to half-epigynous
or epigynous, typically with a well-defined hypanthium, the sepals (3) 5 (10), free and often
attached to the top of the hypanthium or more often connate or at least adnate to the hypanthium
forming a calyx-tube, imbricate, the petals (3) 5 (10), rarely lacking, free, often rather showy,
usually alternating with and often the same number as the sepals, imbricate; stamens typically in 13 (5) whorls of 5, infrequently as few as 5 and rarely 1 (Aphanes), free or rarely connate basally,
attached to the hypanthium and sometimes originating centripetally; ovary superior to inferior, the
carpels 1 (Amygdaloideae) or several to many, free or occasionally more or less connate to form
a compound ovary with mainly 2 or 5 locules, the styles free, the stigma small and terminal, the
ovule (1) few to several per carpel; fruits mainly of separate follicles or achenes, occasionally
forming drupes, pomes or infrequently capsules, the seeds mostly small.
115 genera and 3,500 species. Nearly cosmopolitan, mainly in subtropical and temperate regions
of the world.
Economically, few families have as many important cultivated trees, shrubs and herbs, or as many
valuable fruit crop plants as the Rosaceae. The diversity of fruit, from berries to pomes to
elaborately presented achenes (as in the strawberry) is hardly matched anywhere else.
Taxonomic problems abound, not the least because of the dominance of apomixis in such genera
as Rubus Sorbus and Crataegus.
POME:
Apple
ETAERIO
of Achenes:
Strawberry,
Geum
HIP:
Rosa
DRUPE:
Cherry
ETAERIO
of Drupes:
Blackberry
SOME HORTICULTURALLY IMPORTANT FLOWERING PLANT FAMILIES
ETAERIO
of Follicles:
Spiraea
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Fabaceae
Fruit a legume, (Pea Pod).
The question of one family, Fabaceae (or its alternative name, Leguminosae), or three families
Mimosaceae, Caesalpiniaceae, and Fabaceae (or its alternative name, Papilionaceae).
Three subfamilies: Caesalpinioideae, Mimosoideae, and Faboideae (or its alternative name,
Papilionoideae).
Mimosoideae (BRUSH FLOWERS)
Trees, shrubs, lianas or rarely herbs; leaves usually bipinnately compound,occasionally once
pinnate or reduced to a narrow phyllodia as in some species of Acacia, the stipules sometimes
specialised into prickles or spines; flowers small, bisexual or rarely unisexual, actinomorphic, the
sepals (3) 5 (6), connate and forming a calyx-tube, occasionally reduced or even obsolete, the
petals (3) 5 (6), free or much more commonly connate into a tube, alternating with and typically
the same number as the sepals; stamens twice as many as the petal or numerous, rarely as many
as the petals, free or more often fused, often highly coloured and forming the bulk of the floral
display of the inflorescence.
56 genera and about 3000 species. Pantropical, especially in arid regions, extending into warm
temperate regions in Australia, and in North and South America.
Acacia 1200 spp. Mimosa 400 spp. ‘mimosa’ of cultivation & florists usually Albizia.
Caesalpinioideae (BUTTERFLY FLOWERS)
Trees, shrubs, infrequently lianas or herbs; leaves usually pinnately compound, occasionally
bipinnate, infrequently unifoliolate or simple as in Bauhinia, sometimes modified into tendrils,
typically with a swollen, basal pulvinus; flowers small or more commonly mid size and rather
showy, bisexual or rarely unisexual, slightly to distinctly zygomorphic but not papilionaceous (but
see Cercis), rarely actinomorphic (Gleditsia), the sepals mostly 5, free or connate and forming a
calyx tube, the petals 5, occasionally lacking, free; stamens (1) 10 (numerous), free or
infrequently slightly connate basally, not highly coloured.
Nearly 160 genera and about 2200 species. Mostly tropical with a few genera in temperate
regions. Cassia, Bauhinia, Gleditsia, Gymnocladus.
Papilionoideae (PEA FLOWERS)
Trees, shrubs, lianas or much more commonly herbs; leaves pinnately or occasionally palmately
compound or trifoliolate, infrequently unifoliolate or simple, sometimes modified into tendrils;
flowers small or more commonly mid size and often showy, bisexual, usually zygomorphic,
perigynous, the sepals mostly 5, usually connate and forming a bilabiate calyx tube, the petals 5,
composed of a free banner or standard, two lateral and free wings, and two partially fused distally
to form a keel; stamens mostly 10, rarely 5-9, commonly diadelphous (9 fused and 1 free),
infrequently all 10 fused, not highly colored.
More than 460 genera and in excess of 12,000 species. Cosmopolitan but mainly in temperate
regions. Trees: Sophora, Robinia,
Climbers: Wisteria
Herbaceous: Phaseolus, Vinca, Medicaago, Trifolium, Lathyrus, Lupinus.
SOME HORTICULTURALLY IMPORTANT FLOWERING PLANT FAMILIES
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SOME HORTICULTURALLY IMPORTANT FLOWERING PLANT FAMILIES
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1 of 2
Keel
petals
1 of 2
Wing
petals
Standard
petal
MIMOSOIDEAE
3,100 species
Topicale trees, shrubs, and some climbers;
leaves bipinnate or pinnate.
Acacia (1,200 spp.)
PAPILIONOIDEAE
12,000 species
Cosmopolitan, mostly herbaceous, or
climbers, leaves pinnate or trifoliate.
Astragalus, Lathyrus, Lupinus,
Cytisus, Laburnum, Wisteria,
2,200 species
Mostly tropical trees and shrubs,
leaves bipinnate or pinnate.
Caesalpinia, Cercis, Gleditsia,
Gymnocladus
CAESALPINOIDEAE
While the fruits fo Fabaceae are easily recognisable as a ‘pea-pod’ the flowers show three basic patterns. Some authors treat
these sub-families as families – Fabaceae, Mimosaceae and Caesalpiiaceae.
FABACEAE (Leguminosae). Three sub-families.
Ericaceae
Mostly shrubs, rarely trees (Arbutus); leaves simple, entire and often ericoid, most evergreen or
sometimes deciduous; inflorescences commonly in racemes; flowers small to large, actinomorphic
to slightly zygomorphic, the sepals (3) 5 (7), free, imbricate or valvate, persistent, the petals (3) 5
(7), free or more commonly sympetalous and campanulate to tubular or urceolate; stamens
usually (6) 10 (20), the anthers inverted, dehiscing by terminal pores or short slits, typically with a
pair of slender, prolonged appendages; ovary superior to inferior, the carpels (2) 5 (10), united to
form a compound (uni-) plurilocular ovary with axile placentation, ovules 1-several per carpel;
fruits a septicidal or loculicidal capsule, sometimes a berry (mostly the Vaccinioideae) or a drupe
(Arbutus).
116 genera and some 3500 species. Cosmopolitan and especially in the cool, temperate and
subtropical regions of the world, including the high mountains in South America, southern Asia
and the Malesian regions.
Many ornamental shrubs. Rhododendrons and azaleas (both Rhododendron - Linnaeus
distinguished Azalea as deciduous). The heather (Calluna) and heath (Erica) are both Old
World in their distribution with the Cape Region of South Africa the home of some 580 of the
665 species. Vaccinium, variously called blueberries, deerberries, bilberries (Fraochán),
cranberries. Gaultheria, Daboecia, Arbutus, Pieris
The majority of species in the Ericaceae occur on acid soils and generally require cool
temperatures. The majority have a direct and profound relationship with one or more
mycorrhizal species of fungi.
Oxydendrum
Stamen, showing
apical pores.
SOME HORTICULTURALLY IMPORTANT FLOWERING PLANT FAMILIES
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A diagram illustrating the importance of flower & fruit structure in distinguishing these 4 families.
Lamiaceae
SOME HORTICULTURALLY IMPORTANT FLOWERING PLANT FAMILIES
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Herbs, subshrubs, shrubs, or trees; stems often square; leaves opposite, simple and mostly entire,
sometimes pinnate; inflorescences arranged mainly in small, compact, axillary cymes congested
into verticillasters; flowers small to mid size, actinomorphic to strongly zygomorphic, the sepals
(4) 5 (8), connate and tubular, often 2-lipped, the petals (4) 5 (6-18), sympetalous, bilabiate (2lipped); stamens epipetalous (stuck to the petals), typically 4, rarely 2; ovary superior, with 2
locules, each with 2 ovules, forming 4, one-seeded lobes; the style arising deep in the lobes of the
ovary, the stigma entire or 2-lobed.
Approximately 290 genera and some 7750 species. Cosmopolitan.
As now defined, the Lamiaceae include a significant portion of the Verbenaceae. Such genera as
Clerodendrum and Teak (Tectona grandis) are now included in Lamiaceae and not
Verbenaceae.
Many species are aromatic - Thymus, Origanum, Mentha. Equally significant are the many
species grown as culinary herbs. Salvia 900 spp.
SOME HORTICULTURALLY IMPORTANT FLOWERING PLANT FAMILIES
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Scrophulariaceae
Herbs, subshrubs, shrubs or trees (stems rarely 4-angled - Scrophularia); leaves alternate or
opposite, rarely verticillate (whorled), simple and entire, or lobed to pinnate; inflorescences very
variable, cymes, racemes, a spike or reduced and solitary; flowers small to large, bisexual,
zygomorphic to nearly actinomorphic, the sepals (2) 4-5, connate, the petals 4-5 (8),
sympetalous, variably shaped, typically labiate, occasionally saccate or spurred at the base;
stamens epipetalous, (2) 4-5, often with one obsolete or reduced to a staminode (lacks an anther
at its tip); ovary superior, the locules united to form a compound, bilocular ovary, the style
solitary, terminal, the ovules many to numerous (rarely 2) per carpel, axile; fruit usually a septicidal
(splitting at the septum) capsule.
190 genera and some 4000 species. Cosmopolitan but especially common in temperate regions
and tropical mountains.
Scrophularia, Verbascum, Antirrhinum, Calceolaria, Digitalis, Linaria, Mimulus,
Penstemon, and Veronica. Hebe differs from Veronica in being a shrub.
SOME HORTICULTURALLY IMPORTANT FLOWERING PLANT FAMILIES
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Campanulaceae
Herbs, sometimes shrubs and small trees; leaves alternate, simple and entire or variously dentate,
lobed or pinnately divided; inflorescences arranged variously into cymes or racemes; flowers
small to large, bisexual or rarely unisexual, actinomorphic (Campanuloideae) or zygomorphic
(Lobelioideae), the sepals (3) 5 (10), connate, the petals (3) 5 (10), sympetalous, campanulate
(bell-shaped) to tubular, occasionally bilabiate or unilabiate; stamens mostly as many as and
alternating with the corolla lobes; pollen-presentation mechanism complex, the anthers variously
connivent (touching one another) or connate (fused together) to form a tube into which the pollen
is shed with the style proceeding through the tube and pushing out the pollen; ovary superior to
inferior, the carpels 2-3 (10) and united to form a compound ovary, the ovules numerous, axile or
variously basal; fruit a capsule, variously dehiscent or infrequently indehiscent, rarely a berry
(Canarina).
90 genera and some 2200 species. Cosmopolitan.
The family is divided into two families or subfamilies, Campanuloideae and Lobelioidea: The nonresupinate flowers of the Campanuloideae are nearly always actinomorphic with a superior ovary
and free anthers, while the resupinate (upside down) flowers of the Lobelioideae are nearly
always zygomorphic with an inferior ovary and connate anthers.
SOME HORTICULTURALLY IMPORTANT FLOWERING PLANT FAMILIES
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Asteraceae
Herbs or shrubs, occasionally lianas or small to medium-size trees, rarely epiphytes or tall trees;
leaves alternate, occasionally opposite, simple and entire to toothed or lobed, infrequently divided
or compound; inflorescences arranged in capitula (heads) or compound flowers (hence
Compositae) of 1 to many, sessile flowers on a single receptacle nearly always subtended by
several series of bracts; flowers mostly small, epigynous (sitting on top of the ovary), either all
alike or of two or more kinds - disk florets and ray (or ligulate) florets. In most species all the
flowers are functionally male and female, but in some there is an outer array of radiate female or
neutral flowers and an inner group of bisexual or functionally male flowers, the sepals fused with
the ovary with the free lobes modified into a pappus (beard), this sometimes reduced or even
obsolete. Petals 5, tubular or discoid and completely sympetalous, ligulate (or rayed) and
zygomorphic with the ligule (sometimes called ray- and disk-florets) 3-5-toothed at its tip;
stamens epipetalous, as many as, and alternating with, the corolla lobes, the pollen sometimes
pushed out by the elongating style; ovary inferior, the carpels united to form a compound,
unilocular ovary; fruits an achene typically crowned with the persistent pappus of scales or
bristles.
Nearly 1,550 genera and some 24,000 species (1/10th of all flowering plants). Cosmopolitan but
mainly in temperate and subtropical regions.
The Asteraceae are the largest family in terms of the number of genera and species, exceeding the
Orchidaceae (800/20,000) in both categories.
Diagram of a capitulum: RAY floret on left. DISK floret above.
SOME HORTICULTURALLY IMPORTANT FLOWERING PLANT FAMILIES
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Liliaceae
Classification of Liliaceae varies greatly from one text-book to another. One widespread
treatment is to place all the species (294 genera / 4500 species) into a single broadly defined
family, separated from the Amaryllidaceae by the possession of superior rather than inferior
ovaries. Some textbooks and taxonomists prefer to lump even these 4 families together, while
others divide the family into at least 22 separate families. Some of these will be familiar, and it is
important to be aware of these different arrangements.
LILIACEAE sensu lato (in the broad sense):
LILIACEAE
AMARYLLIDACEAE
AGAVACEAE
Tulipa
Fritillaria
Lilium
Crinum
Galanthus
Hippeastrum
Narcissus etc.
70 Genera
850 spp.
Agave
Cordyline
Yucca
Aloe
Haworthia
12 Genera
5 Genera
294 genera
4500 species
ALOACEAE
LILIACEAE sensu stricto (in the strict sense) [11 genera / 450 spp.] Cardocrinum,
Erythronium, Fritillaria, Gagea, Lilium, Tulipa.
Perennial herbs from tunicated or non-tunicated bulbs with 1-many fleshy scales; leaves basal or
cauline, alternate or rarely verticillate, the blades linear to ovate; inflorescences axillary or terminal
cymes or racemes, rarely reduced and solitary (Tulipa); flowers typically large, trimerous (3parted) with the tepals (Sepals + Petals) all petaloid and arranged in two whorls of 3, typically
free, the tepals mostly all alike, erect to variously spreading or recurved; stamens 6 in two whorls;
ovary superior, the carpels 3 and united to form a compound, trilocular ovary, the style terminal,
the stigma 3-lobed or 3-crested, the ovules numerous; fruits a loculicidal capsule, the embryo
straight in a fatty endosperm.
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Segregate families of Liliaceae:
ALLIACEAE. The onion family. Agapanthus, Allium, Tulbaghia.
Bulbous. Oleic acids. Leaves sheathing stem. Infl. an umbel. G
THEMIDACEAE. Tritelia Brodiae.
Recently separated from Alliaceae, as being similar but with no oleic acids.
ASPARAGACEAE. Asparagus.
ASPHODELACEAE. Asphodelus, Asphodeline, Eremurus, Kniphofia.
ASTELIACEAE. Astelia.
COLCHICACEAE. Colchicum.
Ovaries below ground, hidden in the bulbs or corms.
CONVALLARIACEAE Convallaria,Lliriope, Ophiopogon, Polygonatum.
Rhizomatous herbs. Flowers arising along leafy stems.
HEMEROCALLIDACEAE Hemerocallis. Day-lilies
HOSTACEAE. Hosta
HYACINTHACEAE. Hyacinthus, Hyacinthoides, Scilla, Muscari,
Bulbous, leaves separate from stem, Inflorescence racemose on a scape, each flower
with a bract.
MELANTHIACEAE. Veratrum
Rhizomatous, leaves sheathing, basal.
RUSCACEAE Ruscus, butcher’s broom.
TRILLIACEAE Trillium, Paris.
SOME HORTICULTURALLY IMPORTANT FLOWERING PLANT FAMILIES
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Layout of the four Liliaceae (sensu lato.) beds in the family beds at Glasnevin. The diagrams
illustrate the main morphological structures that separate the families
Iridaceae
Perennial herbs from rhizomes, corms or bulbs, infrequently evergreen herbs or subshrubs, rarely
annual herbs; leaves basal or cauline, mostly distichous, typically graminoid; inflorescences
arranged in terminal cymes, racemes, spikes or panicles, occasionally reduced to a single flower,
often subtended by 1-few bracts; flowers small to large, actinomorphic or zygomorphic, bisexual,
trimerous with the tepals all alike, often basally connate into a short to occasionally long perianth
tube; stamens 3, opposite the outer tepals; ovary inferior, the carpels 3 and united to form a
compound, trilocular ovary, the style terminal, the stigma 3-lobed, the branches occasionally
lobed again or expanded and petaloid, the ovules (1) numerous; fruits a loculicidal capsule.
Some 77 genera and about 1655 species of nearly a cosmopolitan distribution with
concentrations in Africa, portions of Asia, and Central and South America.
Numerous members of the Iridaceae are cultivated as ornamentals. Iris, Crocosmia
(Montbretia) - dried flowers in water smell like saffron (osmia - Grk. for smell), Crocus,
Gladiolus, Freesia, Watsonia. The inferior ovary and three anthers is almost always diagnostic.
SOME HORTICULTURALLY IMPORTANT FLOWERING PLANT FAMILIES
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Iris pseudacorus – Yellow Flag
GRASSES, SEDGES and RUSHES
SOME HORTICULTURALLY IMPORTANT FLOWERING PLANT FAMILIES
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GRASS
RUSH
SEDGE
Juncaceae – RUSHES
Leaves alternate and basal, the lamina flat to channelled or rounded, usually hollow, sometimes
with pith, stems and leaves may be identical; inflorescences arranged in branched cymes or
reduced to head-like or spike-like clusters; flowers small and somewhat inconspicuous, greenish
to brownish or blackish, rarely whitish or yellowish, the tepals 6, free; stamens 6 (infrequently 3),
free; ovary superior, the carpels 3 and united.
8 genera and perhaps as many as 320 species. Cold to temperate regions in both the North and
South hemispheres, occasionally in the tropical mountains.
The two principle genera are Juncus (225 sp.) and Luzula (80 sp. - 17 in Ireland). Plants of
Juncus and Luzula sometimes form a principle component of the grasslands in wet meadow. A
few species of Juncus are grown as ornamentals.
Cyperaceae – SEDGES
Stems often 3-angled; leaves alternate, often 3-ranked, usually with a closed sheath, the lamina
flat to angular, ligule occasionally present; inflorescences each subtended by a scale between the
axis and the flower, the spikes and spikelets themselves commonly arranged in various sorts of
secondary inflorescences; flowers small and inconspicuous, bisexual or unisexual and the plants
monoecious or rarely dioecious, the perianth of 1- 6, short to elongate bristles; stamens typically
3; ovary superior, the carpels united to form a compound, 1-locular ovary, the stigma lobes 2 or
3; fruits a trigonous achene with the seed free from the pericarp. Approximately 146 genera and
more than 5,300 species. Cosmopolitan but mainly in cold to temperate regions.
The largest genus in terms of species numbers is Carex with well over 1000 species. Cyperus
has 600 species. Cotton grass - Eriophorum. The sedge inflorescence is complicated because
of the extreme reduction that has occurred. Cyperus papyrus was used to make paper in
Egypt, hence the latin word papyrus. Also used for making boats. Many ornamentals.
SOME HORTICULTURALLY IMPORTANT FLOWERING PLANT FAMILIES
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Poaceae – GRASSES
herbs rarely woody & arborescent (bamboos); Stems with nodes; leaves with an open or rarely
closed sheath, the lamina flat; inflorescence composed of numerous spikelets, each with 1 or
more individual flowers, each spikelet has two scales at the base, called glumes; each flower is
subtended by a further pair of scales, the bigger lemma and palea) with the inner one (palea)
inserted between the often zig=zag axis (rachilla), the whole forming a floret, the spikes and
spikelets themselves commonly arranged in various sorts of secondary (often paniculate,
racemose or spikelike) inflorescences; the perianth of 2 connate (fused) outer segments (the
palea) with the third one lacking and the inner segments of 2-3 minute scales (the lodicules);
stamens typically 3; ovary superior, the carpels united to form a 1-locular ovary, the filiform
stigma lobes often distinctly feathery; fruits a dry (seldom fleshy) caryopsis with the seed fused to
the pericarp.
Approximately 660 genera and more than 10,000 species.
The grasses generally have a unique fruit (caryopsis). As a family, the Poaceae are probably the
single most important family to the survival of humans and their culture. The grasses provide a
multitude of foods, fibres and construction materials.
Arecaceae – PALMS
SOME HORTICULTURALLY IMPORTANT FLOWERING PLANT FAMILIES
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Arborescent, infrequently climbing (rattans) and rarely stemless; Branching very rare; leaves
evergreen, spirally arranged pinnately or palmately divided, infrequently entire; inflorescences
arranged in an axillary, spadix-like panicle or spike subtended by 1-several spathes; flowers
numerous, the sepals 3, leathery to fleshy, the petals 3, somewhat to distinctly smaller than the
sepals; stamens 6-numerous but most commonly 6; ovary superior, the carpels united into a
compound, 3-locular ovary, the ovule 1 per locule or carpel; fruits a dry or fleshy drupe,
occasionally fleshy.
About 200 genera and 3000 species of subtropical and tropical regions, infrequently in warm
temperate zones.
Economically the palms are among the most important of the flowering plants, ranking among the
top ten of angiosperm families in significance to the survival of humans and their culture.
Numerous species are used for food, fibre and construction. Fine oils and waxes are obtained
from several. Many genera are planted as ornamentals.
Orchidaceae – ORCHIDS
Small to large, mycotrophic or occasionally saprophytic herbs, terrestrial or more often epiphytic,
occasionally climbing or scandent, rarely subterrean, some with fibrous or tuberous like roots or
rhizomes; leaves alternate, distichous; inflorescences arranged in axillary or terminal racemes
spikes or panicles; flowers small to large, zygomorphic, epigynous, resupinate (upside-down),
bisexual or rarely unisexual and the plants monoecious or dioecious; sepals and petals strongly
differentiated or all of the tepals petaloid, arranged in two whorls of 3, the sepals green or
coloured, the petals larger than the sepals and often with the median petal largest and highly
modified into a labellum, sometimes spurred or saccate, the latter two petals occasionally
somewhat sepaloid; Anthers and stigma fused into a column; stamens (3, 2, or1) highly modified,
opening by a slit, and in most species the pollen united into 2-8 club-shaped pollinia with quicksetting glue; ovary inferior, a unilocular ovary with parietal placentation, the style terminal, the
ovules numerous (to 1 million); fruit a capsule, the embryo tiny and undifferentiated in little or no
endosperm; germination dependent upon a fungus, forming a protocorm.
Approximately 740 genera and about 18,000 species mainly of tropical regions, with several
extending into temperate or even cold regions, but rare there. Orchid pollination is remarkable as
to the multitude of avenues the plants and their pollinators have taken to accomplish the simple
transfer of pollen to the stigma. The pollinia have allowed the one-off pollination of 10,000s of
ovules. Traditionally classification schemes finish the dicotyledons with the Asteraceae and the
monocotyledons with the Orchidaceae – representing the evolutionary crown of the flowering
plants
Agronomically virtually worthless (Vanilla), aesthetically probably worth more than all other plants
combined. Intrageneric hybrids common (up to 20 spp. & 5 genera in 1 plant).
SOME HORTICULTURALLY IMPORTANT FLOWERING PLANT FAMILIES
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