This version of the key may be read an used as a traditional printed key, but it is also interactive to the extent that selectiing an option will jump to the appropriate place in the key, where the next option can be selected.
In addition, selecting the key couplet number will jump backwards to the option that lead to that selection, enabling a degree of controled backtracking to a position of confidence if a wrong choice in the keying process is suspected.
| 1 |
Free floating, aquatic plants... |
...2 |
| Anchored plants, usually terrrestrial,
epiphytic or lithophytic... |
...4 |
| 2 |
Sterile lamina 1 - 3-pinnate, 40 -
400 mm long, 10 - 200 mm wide... |
Parkeriaceae
(Ceratopteris) |
| Sterile lamina simple, paired and 7
- 30 ( - 40) mm long or crowded and 1 - 2 mm long... |
...3 |
| 3 |
Frond of 2 foliar, floating leaves
and 1 submerged, root-like sporocarp bearing leaf; floating leaves
broad or rounded... |
Salviniaceae
(Salvinia) |
| Frond of numerous, crowded, ovate to
triangular, bilobed leaves; spore capsules in axils of submerged leaf
lobe... |
Azollaceae
(Azolla) |
| 4 |
Stems jointed, rush-like, sometimes
hollow; leaves small, whorled, joined in a sheath at stem nodes... |
Equisetaceae
(Equisetum) |
| Stems not jointed; leaves not whorled
and joined in a sheath at stem nodes... |
...5 |
| 5 |
Sporangia in the axil of a forked leaf,
and fused in groups of 2 or 3, or in the axils of spophylls (often
in cone-like structures), or in swollen leaf-bases... |
...6 |
| Sporangia free, laminal or marginal
and either scattered or in clusters (which may in turn be confluent),
or sporangia occurring in scattered or clusted sori, aggregated into
a spike or enclosed in sesssile or stalked receptacles... |
...9 |
| 6 |
Sporangia fused in groups of 2 or three
and born in the axils of forked leaf... |
Psilotaceae |
| Sporangia solitary, in the axils of
sporophylls (often in cone-like structures) or in swollen leaf bases... |
...7 |
| 7 |
Sporangia in axils of sporophylls that
are often aggregated in cone-like structures... |
...8 |
| Sporangia in swollen leaf bases on
adaxial side; plants aquatic or semiaquatic... |
Isoetaceae
(Isoetes) |
| 8 |
Sterile leaves and sporophylls with
a minute basal ligule; sporangia dimorphic; megasporangia assuming
the shape of the 4 developing megaspores; microsporangia globose to
reniform... |
Selaginellaceae
(Selaginella) |
| Sterile leaves and sprophyllls lackng
a basal ligule; sporangia uniform, subglobose to reniform... |
Lycopodiaceae |
| 9 |
Fronds compromising a steril lamina
and a fertile spike diverging from a common basal stalk... |
Ophioglossaceae |
| Sterile and fertile fronds borne separately
on the rhizome or all mature fronds fertile... |
...10 |
| 10 |
Sori completely enclosed in sessile
or stalked woody spore receptacles at the base of the stipe; sterile
fronds with 2 or 4 apical leaflets in oposite pairs, or leafless and
consisting of a stipe only... |
Marsileaceae |
| Sori not enclosed in spore receptacles,
either completely exposed or partialy protected by an indusium or
reflexed leaf margin; sterile fronds simple or variously dissected,
lacking apical leaflets... |
...11 |
| 11 |
Pinnae with swollen jointed bases;
sori composed a double row or ring of free sporangia, or fused in
a bivalved synangium... |
Marattiaceae |
| Pinnae lacking swollen jointed bases;
sori scattered or aggregated, but not composed of a double row or
ring of free sporangia or fused in bivalved synangia... |
...12 |
| 12 |
High-climbing plant; fertile and sterile
pinnae markedly different; sori borne on marginal projections of pinnules... |
Lygodiaceae |
| Plants not climbing, or if climbing,
sori borne on the margin on the underside of lamina, not on apices
of laminal axes, nor on marginal projections... |
...13 |
| 13 |
Sori on sort pinnate or digitate segments
at apices of stipe-like, often dichotomously branching lamina axes... |
Schizaeaceae |
| Sori borne on the margin or underside
of lamina, not on pinnate or digitate fertile segments at the apices
of lamina axes... |
...14 |
| 14 |
Rhizome and stipe spongy; sporangia
solitary, in two marginal rows; aquatic and semiaquatic ferns... |
Parkeriaceae
(Ceratopteris) |
| Rhizome and stipe not spongy, sposrangia
not solitary in marginal rows; mostly terrestrial, lithophytic or
epiphytic ferns... |
...15 |
| 15 |
Rhizome a single arborescent runk over
c. 2 m tall; tree ferns... |
...16 |
| Rhizome not an arborescent trunk... |
...18 |
| 16 |
Sorangia massed along minor veinlets
of lower pinnules of primary pinnae, becoming confluent, not aggregated
in discrete sori, exindusiate... |
Osmundaceae
(Todea) |
| Sori discrete, with a hood-shaped 2-lipped
indusium, or exindusiate with a basal ring of scales... |
...17 |
| 17 |
Stipe bases scaly, lacking hairs; sori
between midrib and margin, with a hood-shaped indusium or exindusiate
with a basal ring of scales... |
Cyatheaceae
(Cyathea) |
| Stipe bases hairy, lacking scales;
sori marginal, with a 2-lipped indusium... |
Dicksoniaceae |
| 18 |
Fronds appearing dichotomously branched,
or rarely in opposite pairs (Diplopterygium), usually with
dormant buds in the axils... |
Gleicheniaceae |
| Fronds simple or variously divided,
not appearing dichotomously branched, without dormant buds in the
axils... |
...19 |
| 19 |
Ultimate segments small and rounded
with strongly reflexed margins forming pouch-like cavities... |
...20 |
| Ultimate segments variable, lacking
strongly reflexed margins that for a pouch-like cavity... |
...21 |
| 20 |
Lamina filiforme or pinnate, rhizome
thick, densely clothed in reddish hairs... |
Platyzomataceae
(Platyzoma) |
| Lamina or two pinnate branches at the
stipe apex; rhizome slender and wiry with scattered appresssed scales... |
Gleicheniaceae
(Gleichenia abscida) |
| 21 |
Sporangia in discrete, oblong or irregular
patches, restricted to the basal half of minor costules; fronds filmy... |
Osmundaceae
(Leptopteris) |
| Sporangia not as above... |
...22 |
| 22 |
Sori covered by an indusium or by a
reflexed pinna/pinnule margin... |
...23 |
| Sori lacking an indusium or other form
of covering... |
...47 |
| 23 |
Most or all sori borne on the underide
of the pinnae away from the margins... |
...24 |
| Sori confined to marginal or submarginal
areas of the ultimate lamina segments; if submarginal, usually covered
by a reflexed pinna/pinnule margin... |
...32 |
| 24 |
Sori rounded or elliptic... |
...25 |
| Sori elongate... |
...29 |
| 25 |
Lamina simple, 1-pinnate or 1-pinnatifid... |
...26 |
| Lamina 2 - 4-pinnate or -pinatifid... |
...28 |
| 26 |
Sori on anastomosing veins parallel
and usually adjacent to the midrib; indusium semicircular... |
Blechnaceae
(Doodia) |
| Sori on free veinlets, on free included
veinlets or on vein tips, usually not adjacent to midrib; indusium
orbicular to reniform... |
...27 |
| 27 |
Pinnae articulated to the rachis, or
stipe articulated to a phyllopodium; rhizome scales peltately attached;
hydathodes prominent on upper surface of lamina at vein endings; basal
veins from adjacent costules not uniting to form a translucent sinus
membrane between two pinna lobes... |
Davalliaceae
(Oleandraceae) |
| Pinnae not articulated tothe rachis;
stipe not articulated to a leaf-like outgrowth of the rhizome; rhizome
scales attached along their basal margins; hydathodes absent; basal
veins from adjacent costules often uniting and terminating in a translucent
sinus membrane between 2 pinna lobes... |
Thelypteridaceae |
| 28 |
Basal pinnae often enlarged on their
basal side; indusium usually glabrous or with long silky hairs; rhizome
scales +/- glabrous |
Dryopteridaceae |
| Basal pinnae not enlarged on their
basal side; indusium with short capitate hairs; rhizomes scales hariy... |
Thelypteridaceae
(Macrothelypteris) |
| 29 |
Sori in long grooves close to the midrib
or following anastomosing veins; groove margins extending into flaps;
lamina simple; rhizome with clathrate scales... |
Vittariaceae |
| Sori not in grooves, covered by an
indusium; lamina usually 1-4 pinnate; rhizome scales ussually not
clathrate (except Aspleniaceae)... |
...30 |
| 30 |
Sori parallel to midrib of ultimate
sedments... |
Blechnaceae |
| Sori oblique to midrib of untimate
segments... |
...31 |
| 31 |
Rhizome scales clathrate... |
Aspleniaceae |
| Rhizome scales not clathrate... |
Athyriaceae
(Woodsiaceae) |
| 32 |
Indusium bivalved or cup-shaped... |
...33 |
| Indusium +/- rouned to elongate, flap
like, or a reflexed pinna/pinnule margin... |
...36 |
| 33 |
Sori borne on short or elongate receptacles
terminating the veins or projecting from the lamina margins; lamina
filmy 1-cell thick (rarely 2 or 3 cells) and translucent or lamina
reduced to minute hairs (Sphaerocionium) or a barely perceptible
wing along the axes of the frond (Crepidomanes p.p., Cephalomanes)... |
Hymenophyllaceae |
| Sori not borne on receptacles; lamina
not as above... |
...34 |
| 34 |
Rhizome and stipe base scaly, lacking
hairs... |
Davalliaceae |
| Rhizome and stipe base hairy. lacking
scales... |
...35 |
| 35 |
Indusium of two distinct lips; inner
lip membranous, outer lip a reflexed pinnule lobe... |
Culcitaceae
(Dicksoniaceae) |
| Indusium cup-like... |
Dennstaedtiaceae |
| 36 |
Sori rounded to elliptic... |
...37 |
| Sori elongate or confluent along pinna
margin... |
...42 |
| 37 |
Indusium false (a reflexed pinna margin)
or a flap opening towards the centre or base of pinna... |
...38 |
| Indusium reniform, semicircular, half
cup-shaped or a broadly attached flap opening towards the pinna margin... |
...40 |
| 38 |
Rhizome and stipe base hairy, lacking
scales... |
Dennstaedtiaceae
(Hypolepis p.p.) |
| Rhizome and stipe base scaly, lacking
hairs... |
...39 |
| 39 |
Each ultimate segment with a single
vein; fronds to c. 6 cm tall; epiphytic ferns... |
Grammitidaceae
(Calymmodon) |
| Each umtimate segment witn many veins;
most fronds at least 10 cm tall; terrestrial ferns... |
Adiantaceae |
| 40 |
Rachis deeply grooved; lower margin
of pinna and pinnules decurrent on edge of rachis groove; midrib rarely
present |
Lindsaeaceae |
| Rachis not deeply grooved; lower margins
of pinnae and pinnules not decurrent; midrib usually present... |
...41 |
| 41 |
Rhizome and stipe base hairy; lacking
scales... |
Denstaedtiaceae
(Microlepia) |
| Rhizome and stipe base desnely scaly,
lacking hairs... |
'Dennstaedtiaceae'
('Oenotrichia') |
| 42 |
Lamina simple, entire; sori in long
grooves with groove margins extending inwards as indusium-like flaps;
rhizome scales clathrate; usually epiphytic ferns... |
...Vittariaceae
(Vittaria) |
| Lamina 1 - 4-pinnate or pinnate-pinnatifid;
sori not in grooves; rhizome scales not clathrate; usually terestrial
ferns... |
...43 |
| 43 |
Sori covered by a reflexed pinnule
margin, sometimes also by a membraneous true indusium (best seen in
immature fronds)... |
...44 |
| Sori covered only by a true indusium
attached at the base and opening towards the margin... |
...46 |
| 44 |
Frond to 2 ( - 3) m tall; rhizome long-creeping,
hairy or scaly; stipe and rahcises predominantly yellow-brown |
Dennstaedtiaceae
(Pteridium, Histiopteris) |
| Frond to 50 ( - 70) cm tall with a
creeping to erect scaly rhizome and dark brown to black rachises;
or frond to 2 m tall, but with a short, erect rhizome and predominantly
pale stipe and rachises... |
...45 |
| 45 |
Stipe and rachises dark brown to black,
usually glossy; fronds usually more than 70 cm tall... |
Adiantaceae |
| Stipe and rachises pale green, stramineus,
pale brown or mid brown, rarely glossy; fronds usually more than 70
cm tall... |
Pteridaceae |
| 46 |
Lowere margins of pinnae and pinnules
decurrent on edge of rachis groove; midrib rarely present... |
Lindsaeaceae |
| Lower margins of pinnae not decurrent
on edge of rachis groove; midrib usually present... |
Davalliaceae
(Oleandraceae:
Nephrolepis acutifolia) |
| 47 |
Sori discrete or confluent but not
covering all of the underside of the fertile pinnae/pinnules... |
...48 |
| Sori sporangia covering the whole of
the underside of the fertile pinnae/pinnules ... |
...60 |
| 48 |
Sori rounded or elliptic, remaining
discrete... |
...49 |
| Sori elongate, or if rounded, submarginal
and confluent... |
...55 |
| 49 |
Lamina of two large, flabellate and
deeply incised halves; rhizome with coarse dark bristles... |
Dipteridaceae
(Dipteris) |
| Lamina simple to many-times-pinnate,
not of two large, flabellate and deeply incised halves; rhizome usuall
with scales or hairs... |
...50 |
| 50 |
Lamina 2 - 5-pinnate; terrestrial ferns... |
...51 |
| Lamina simple, 1-pinnatifid, 1-pinnate,
1-pinnate-pinnatifid or dichotomously branched; mostly epiphytic ferns... |
...52 |
| 51 |
Rhizome scaly... |
Dryopteridaceae
(Lastreopsis p.p.;
Dryopteris hasseltii) |
| Rhizome hairy, without scales... |
Dennstaedtiaceae
(Hypolepis p.p.) |
| 52 |
Sori forming 2 irregular rows between
each pair of primary veins... |
Dryopteridaceae
(Coveniella) |
| Sori not forming two irregular rows
between each pair of primary veins... |
...53 |
| 53 |
Rhizome scales peltate and/or clathrate;
stipes articulated to the rhizome or to a short, erect leaf-like outgrowth
of the rhizome... |
Polypodiaceae |
| Rhizome scales neither peltate nor
clathrate, usually attached along their basal margins; stipes not
articulated to the rhizome nor to a short, erect, leaf-like outgrowth
of the rhizome... |
...54 |
| 54 |
Lamina simple, 1-pinnatifid, 1-pinnate,
or dichotomomously branched; veins free, simple or forked... |
Grammitidaceae |
| Lamina 1-pinnate-pinnatifid; veins
nearest costa usually anastomosing with an excurrent vein... |
Thelypteridaceae
(Pneumatopteris) |
| 55 |
Sporangia borne on narrow, apical portion
of lamina... |
Polypodiaceae
(Belvisia) |
| Sproangia borne in laminal or marginal
sori... |
...56 |
| 56 |
Mature fronds simple or deeply pinnatifid,
not pinnate; mainly epiphytic ferns... |
...57 |
| Mature fronds 1 - 3-pinnate; terrestrial
ferns... |
...58 |
| 57 |
Frond 1 - 3 cm tall; lamina simple;
sori sunken in submarginal grooves parallel to the midrib... |
Grammitidaceae
(Scleroglossum) |
| Frond 30 - 80 cm tall; lamina deeply
pinnatifid; sori not sunken, oblique to midrib... |
Polypodiaceae
(Colysis) |
| 58 |
Rhizome climbing or scrambling; fertile
frond much narrower than sterile frond with linear segments 15-20
cm long and 2 - 3 mm wide... |
Blechnaeceae
(Stenochclaena) |
| Rhizome creeping or erect; fronds not
strongly dimorphic... |
...59 |
| 59 |
Rhizome with clathrate scales; lamina
densely covered in hairs; sori laminal, growing on free veins... |
Aspleniaceae
(Pleurosorus) |
| Rhizome with dark bristles or basally
attached non-clathrate scales; lamina glabrous or variously hairy;
sori marginal, or if laminal, the pinnae glabrous and the sori either
growing on free or anastomosing veins, or occupying a continuous band
bewteen the midrib and margin... |
Adiantaceae |
| 60 |
Sporangia massed along minor veinlets
of lower pinnules of primary pinnae, becoming confluent; stipes with
persistent basal stipular expansions... |
Osmundaceae
(Todea) |
| Sporangia not massed along minor veinlets
of lower pinjules of primary pinnae; stipes lacking persistent basal
stipular expansions... |
...61 |
| 61 |
Rhizome with thick fleshy prop roots;
fronds 1 - 4 m tall... |
Pteridaceae
(Acrostichum) |
| Rhizome without prop roots; most or
all fronds less than 1 m tall... |
...62 |
| 62 |
Rhizome mostly creeping or climbing,
dorsiventral; stipes articulated to the rhizome or +/- decurrent on
it... |
Lomariopsidaceae |
| Rhizomes mostly erect, often forming
a short trunk; stipes not articulated to the rhizome... |
Blechnaceae
(Pteridioblechnum,
Blechnum p.p.) |
