Updated by Derek Butcher & Eric Gouda: 10-02-2020 10:35:45.

1STAMENS & STYLELonger than the petals.17
Shorter than or equalling the petals.2
2FLOWERWith small asymetrical sepals.15
Flowers very small.
With symetrical sepals3
3PETALshort, to 5cm long5
long, 9cm or more3A
3APETALlong, straplike, lax to hanging4
long, more or less erect3B
3BPETALwith appendage3C
without appendage, plant bulbose,trigalensis
inflo almost capitate
without appendage, plant funnel shapedzarumensis
inflo bipinnate, spikes 30cm long, petals
13cm long
3CPLANTbulbose, petals to 14cm long withboeghii
funnel shaped, petals to 12cm longdrewii
with appendage
4INFLORESCENCESimple. Floral bract longer than sepalsviridiflora
Compound. Floral bracts about equallingmacropetala
sepals, Epiphyte
Compound. Floral bract shorter than sepalsgrandis
6LEAF SHEATHSpreading on the stem making a funnel6A
shaped rosette.
forming a tubular rosette, leaves to 40cmcernua
long, sheath very broad, almost as long as
the very narrow blade
Forming a spherical 7-11 cm high, secundboqueronensis
claw-like rosette. Blades 4-7 cm long
tapering to a long filiform tip
Forming a bulbose rosette.6B
6ASCAPE1 - 2 cm long, inflorescence sunkmauryana
in rosette, leaves white scaled
mauryana, with secund leavesvar secundifolia
1.5 - 3 cm long, inflor exceeds leaf rosetteteloloapanensis
leaves grey scales
longer, inflorescence well above rosettechontalensis
Petals appendaged
longer, much exceeding the leaves, inflorobusta
digitate with few spikes, floral b purple
exceeding the sepala
to 60cm long, erect, inflo to 65 x 20cm,yerbasantae
with to 25 spikes
6BLEAVESAlmost filiform7
to 3cm wide, inflorescence hanging,bakiorum
branches spreading
3 cm wide, inflorescence hanging,limonensis
cylindric, petals appendaged
7INFLORESCENCEOn long stem, which is as long or longer thanplumosa
the leaf. Leaf with white feathery scales.
stem shorter than leaf rosette, 5-8 cm longcaballosensis
Leaf dense grey white frosty scales
abaxially dense felt-like
Almost sessile. Stem much shorter thanatroviridipetala
and masked by the leaves.
Key to T. atroviridipetala
1.Peduncle hardly visible 2
1a.Peduncle short 3
2. Caulescent - dense rosette 15x 12cm wide.
Inflorescence compound densely capitate
atroviridipetala var yagulensis
2a. Stemless – a dense flattened rosette spikes–
mainly one flowered
atroviridpetala var atroviridipetala
3. Short peduncle Leaf sheath – forming a
Bulb, with 2-6 spikes
atroviridipetala var. longepedunculata
Short. Inflorescence almost9
9PLANTLong filiform growth, similar to Beard Mossusneoides
Rosette growth.leaves to 15cm long,lepidosepala
floral bracts green
open rosette, leaves 4-7 cm long, floralteloloapanensis
bracta pink
secund rosette, leaves to 5cm longpenascoensis
floral bracts intensive pink
10PETALappendaged, Flower dense distichouschontalensis
Spike sword-shaped
Not appendaged11
11FLOWERArranged dense distichously on13
rhachis. Spike short swordshaped
Arranged laxly on rhachis. Floral stemixioides ssp viridiflora
hanging ca 5 flowers polystichous.
polystichous. Floral bract pink.
13PLANTBase bulblike.ignesiae
Base NOT bulblike.14
14FLORAL BRACT2.5 cm long, pink grey scales.tortilis
Flower emerald green.(ehrenbergii)
3.5 cm long, smooth yellowish.lotteae
Flower yellow green.
15 (2)FLORAL BRACTLonger than sepals.R tenuispica
Shorter than sepals.16
16SCAPE BRACTLonger than the internodes.Rparviflora v. expansa
Small, barely half as long as thecommixa
17 (1)INFLORESCENCE.Compound.21
18FLOWERpolystichous, inflo fusiform to 9 x 3 cmerubescens
generally pendant, Floral bracts imbricate(benthamiana)
petals to 7 cm long
polystichous, inflo not fusiform to 7 cmerubescens
generally pendant, Floral bracts spreadingvar patentibracteata
petals to 5 cm long
polystichous, inflo narrower than 3cmarroyensis
pendent , petals to 7 cm long
polystichous, scape a little recurved notquaquaflorifera
pendent, Inflo 10cm x 3cm, petals to 5.5cm
18BINFLORESCENCE2 cm wide, floral bracts mainly lepidoteincurva
petals to 3.6 cm long
2cm wide, floral bracts glabrous, petalspenduliscapa
to 6cm long
3 cm wide, bent upwards in middlecurvispica
19FLOWERArranged laxly on rhachis.fresnilloensis
Plant to 22 cm high, scape toor karwinskyana
12 cm long
Arranged closely on rhachis.20
Inflorescence sword shaped.
20STAMENSand style longer than petals20A
included in petals, only style exceedingpetraea
20ALEAFGreen, not strikingly scaled.cryptopoda
Dense grey scaled. Spike 20cm x 1.5cmachyrostachys
Dense grey scaled, spike 7cm x 2cmrayonesensis
Dense grey scaled, Spike 16cm x 4cmmarabascoensis
21 (17)PLANTWith hanging inflorescence.21A
with decurved scape, inflorescence densearpocalyx
bipinnate, floral bracts red
With erect inflorescence.21D
21ASPIKESide spikes almost parallel21C
Side spikes at right angles21B
21BSCAPE20 cm long, inflorescence to 10 cm longalfredo-lauii
20cm long, inflorescence 30-80cm longhromadnikiana
spikes 12 x 2.5cm
20cm long, inflo 25cm long, 38-40 spikessupermexicana
10x4cmv. pendula
50 cm long, inflorescence 30 - 60 cm longprodigiosa
spikes 9 x 5cm
21CSPIKESlax, floral bracts 35 mm longpereziana
petreziana but floral bracts 25 mm long,pereziana v canescens
strongly lepidote
rhachis not visible21E
21DPETALSsoon drooping, Inflo to quadripinnatepaniculata
remaining fairly rigid21F
21ESCAPEalmost lacking to 25cm long, petalszaragozaensis
without appendage
3 - 6 cm long, inflorescence 18 - 25 cmincurva
long, spikes long, floral bracts not keeled
10cm long, Inflo 16cm long, Spikes 8cmlutheri
long, floral bracts keeled, top 3-4 bracts at
top of spike sterile
17 - 21 cm long, inflorescence 24 - 30 cmcastaneobulbosa
long, spikes long, floral bracts keeled
To 20 cm long, Inflorescence to 14 cm longstrobeliae
spikes very short, to 3 cm long hidden by
the primary bracts which have wavy edges
21FRHACHISzigzag angled21G
straight to almost straight21H
21GFLORAL BRACTSsmooth and sepals smoothlimbata
prominently nerved and sepals nervedcalcicola
glabrous, green sometimes withpink edgescucaensis
inflorescence simple to once branched to
twice branched, peduncle and rhachis
salmon coloured
21HPETALSwith appendage, green with violet specklescereicola
spike narrow, to 15mm wide
without appendage22
22SPIKEsuberect, to 25, long and narrow to 30x2cm,taxcoensis
stipes 11-18 cm long, floral bracts densely
suberect to 23, long & narrow, to 26 x 2.4cmreligiosa
stipes 14-28 cm long, floral bracts mostly
glabrous, pruinose
erect, 8-16, long and narrow, to 30x1.5cmzacualpanensis
sub-cylindric, 3.5 -5.7 cm long, 2-5 flowersfascifolia
floral bracts orange, ca equalling sepals
Sword shaped.22A
22ARHACHISvisible, leaf rosette narrow funnel formsuesilliae
Not visible23
23SCAPEShort, not taller than the leaf rosettecryptopoda
one or two spikes, petals yellow-green
short, about equalling rosette, 7 - 13mixtecorum
spikes, petals yellow-green
as long as leaf rosette, 15-30 spikes, floralcelata
bracts red, exceeding sepals glabrous only
at top, petals yellow green
To 20cm long inconspicuous hidden byborealis
leaves 16-30 spikes
Long, or exceeds the leaf rosette.23A
23APRIMARY BRACTHides bottom spikes. Petal yellow green23B
Narrow, longer than the bottom spikesmarceloi
does not hide bottom spikes.24
23BINFLORESCENCE30 to 45 cm long. Primary bracts pinkcossonii
long attenuate
20-30cm long, primary bracts pinklomae-blancae
short attenuate
to 20cm long, primary bracts red, longmacrochlamys
attenuate, spikes erect
To 17cm long. Primary bracts pale greencarlos-hankii
beneath reddish above, long attenuate,
spikes spreading
To 15 cm long, primary br. rose, petalssierrahalensis
5 cm long
24FLORAL BRACTglabrous,shiny green to yellowish green.24A
glabrous, shiny redjalisco-pinicola
Grey scaled.24B
24AINFLORESCENCEto 70cm long, with up to 40 spikes, primarysupermexicana
bracts long linear, more than 1/2 the
bottom spikes
supermexicana but inflor compactsupermexicana
cylindric, posterior sepals 5 mm connatevar. saxicola
To 25 cm long with up to 8 spikes, primaryroland gosselinii
bracts much shorter than the spikes
to 25cm long, with up to 5 digitate spikesmacvaughii
primary bracts 2.5cm long, petals greenish
to 25cm long, with up to 8 spikes, primaryhintoniana
bracts large but not as long as the spikes
To 10cm long with mainly 4 but up to 6 spikesrothii
24BPRIMARY BRACTBroadly oval shaped with the bottombourgaei
ones having a long awllike tip.Inflo to 30cm
long, acute floral bracts equal sepals,
sepals lepidote
broadly oval shaped with the bottom onestakizawae
having a long awl-like tip, inflo 25-80cm
long, floral bracts acuminate with filiform
tip equalling the sepals, sepals nearly
Broadly oval shaped with the bottomnuyooensis
ones having a long awllike tip.Inflo to 60cm
long, floral bracts longer than sepals
With no long awllike tip.24C
24CSCAPETo 20 cm long. Floral bract green withschusteri
scaled red top.
To 55 cm long. Floral bract pink, grey scaledroseoscapa