| 1 | STAMENS & STYLE | Shorter than or equalling the petals | 10 |
| | Longer than the petals | 2 |
| 2 | INFLORESCENCE | Simple. | 3 |
| | Compound | 4 |
| 3 | PLANT | With long stems | albida |
| - | Stemless | 3A |
| 3A | FLOWERS | very lax | 3B |
| | Dense | 3C |
| 3B | SCAPE | long, flowers erect, petals greenish white | fresnilloensis |
| | long, flowers at right angles, petals white | flexuosa var. alba |
| 3C | SCAPE | long, flowers dense, infl. Oval, rhachis just | |
| | visible, petals appendaged, white | 3D |
| | as long as leaves, petals not appendaged, | verapazana |
| | spike distichous 20x5cm, floral bracts red | |
| | missing, | ionantha 'Druid' |
| 3D | FLORAL BRACT | purple, upper third white, | V correia-araujoi |
| | bright red to yellow or green | V. flammea |
| 4 | SCAPE | Long | 6 |
| | Very short, masked by the leaves | 5 |
| 5 | LEAF | Green. Inflorescence 4cm long densely | moscosoi |
| | ellipsoid | |
| | green with violet spots near tips, inflo | tillii |
| | cylindric, 30cm long, branches 5.5x2.5cm | |
| | petals white | |
| | Green, Inflo to 25cm long, branches 3-4cm | may-patii |
| | long, petals whitish green | |
| | Sheaths orbicular, grey, Blades involute | bulbosa f. alba |
| | Floral bracts yellow | |
| - | With coarse grey scales | 5A |
| 5A | INFLORESCENCE | Upright, nestling in the leaves, densely | plagiotropica |
| | egg shaped | |
| | Pointing downwards | matudae |
| | Floral bract rose, sparsely scaled | |
| 6 | FLORAL BRACT | Arranged densely on rhachis. | 6A |
| | Arranged laxly on rhachis | 7 |
| 6A | SPIKE | Sword shaped | 6B |
| | linear shaped, 15cm long, red | xlineatispica |
| 6B | PLANT | bulbose at base | pseudobaileyi fa. alba |
| | not bulbose at base | 6C |
| 6C | PETALS | forming a tube, plant small | polystachia |
| | 8cm long, erect but soon | baliophylla |
| | pendant, plant large | |
| | 5cm long, forming a tube, plant with very | ilseana |
| | thin leaves | |
| 7 | RHACHIS | Carmine, Strongly angled in zigzag form | limbata |
| | Floral bract enclosing the rhachis | |
| | internodes contiguous with rhachis for | |
| | 2/3. floral bracts 8-9 mm wide | |
| | Green to pink, Strongly angled in zigzag | izabalensis |
| | form. Floral bract enclosing the rhachis | |
| | floral bracts 6-12 mm wide | |
| | angled in zigzag form | comitanensis |
| | Floral bract enclosing the rhachis | |
| | internodes contiguous with rhachis for | |
| | 1/2 - 1/3 , floral bracts 15mm wide | |
| | Not angled in zigzag form | 8 |
| | The internodes at the most lightly bent. | |
| 8 | SEPALS | lepidote | calcicola |
| | glabrous | 9 |
| 9 | LEAF | With coarse grey scales, | pringlei |
| | 15-20cm long. Plant freely offsetting. | |
| | With minute pale appressed scales. | utriculata |
| | To 100cm long. Plant rarely offsetting. | |
| 10 (1) | INFLORESCENCE | Simple | 42 |
| | Compound | 11 |
| 11 | SEPAL | Symmetrical | 26 |
| | Asymmetrical | 12 |
| | (Racinaea and flowers generally very small ) | |
| 12 | FLORAL BRACT | Shorter than the sepals | 19 |
| | Equalling or longer than the sepals | 13 |
| 13 | FLOWER | Arranged laxly on the rhachis | 15 |
| | Arranged closely on the rhachis | 14 |
| 14 | FLORAL BRACT | Red. Bottom of the plant thickened bulblike. | R undulifolia |
| | Leaf edge wavy | (was crispa) |
| | Red. A narrow bulbose rosette, leaf edge | R pulchella |
| | wavy, flowers upward secund | |
| | Green. Bottom of the plant not thickened | R spiculosa |
| | bulblike. Leaf edge smooth. | |
| | Green, bottom of plant forming elliptic | R lutheri |
| | elongate pseudobulb, flowers distichous | |
| 15 | FLOWER | Twisted on one side | 18 |
| | Not twisted on one side | 16 |
| 16 | FLOWER | Spreading | 16A |
| | Upright | 17 |
| 16A | PLANT | rosulate, leaf blades 20-70mm wide | insularis |
| | pseudobulb | 16B |
| 16B | LEAF BLADES | 8mm wide, Inflorescence bipinnate | R almeriae |
| | 35mm wide, Inflorescence tripinnate | diffusa |
| 17 | LEAF BLADES | ligulate | 17A |
| | Triangular | 17B |
| 17A | INFLORESCENCE | amply tripinnate | R tenuispica |
| | tripinnate, rhachis geniculate, floral bracts | R subalata |
| | sulcate with strong midnerve | |
| | bipinnate, sometimes lower branches | R. ghiesbrechtii |
| | divided | |
| 17B | LEAF BLADES | sub triangular, 4cm wide, floral bracts | R. elegans |
| | not lepidote | |
| | thin triangular, 2.5 cm wide, floral bracts | R. pugiformis |
| | lepidote | |
| 18 | FLOWER | Twisted upwards | R fraseri |
| | twisted to front, floral bracts remain | R riocreuxii |
| | distichous | |
| | Twisted downwards | R pectinata |
| 19 (12) | FLOWER | Arranged laxly. Rhachis visible | 21 |
| | Arranged closely. Spike 15-20 flowered | R multiflora |
| | scape bracts exceed the internodes, lower | |
| | primary bracts exceed branches | |
| | multiflora where lower primary bracts do | multiflora v decipiens |
| | not exceed banches | |
| | multiflora where leaf blades acute, short | multiflora v tomensis |
| | acuminate, scape bracts about equal | |
| | internodes | |
| 21 | FLORAL BRACT | Dense appressed scales, rhachis flexuous | R pallidoflavens |
| | petals pale yellow | |
| | dense lepidote, rhachis geniculate | R tandapiana |
| | Dense brown lepidote, Inflo & scape | R lymansmithiana |
| | white woolly | |
| | Glabrous or sparsely scaled | 22 |
| 22 | PLANT | Thickening bulblike at base | 22A |
| | Not thickening bulblike at base | 23 |
| 22A | SCAPE BRACT | Longer than the internodes | R parviflora v.expansa |
| | equalling or shorter than the internodes | 22C |
| 22B | SCAPE BRACTS | equalling the internodes, inflo. white | R. blassii |
| | lepidote | |
| | shorter than the internodes | 22C |
| 22C | LEAF BLADES | 5mm wide, Inflo. bipinnate | 22D |
| | 18mm wide, Inflo. Tripinnate | R. commixa |
| 22D | LEAF SHEATHS | to 6 x 6cm | R. euryelytra |
| | to 4 x 4 cm | R. parviflora |
| 23 | LEAF TIPS | Narrow not rounded | 25 |
| | Rounded with spiny tip | 24 |
| 24 | FLOWER | Erect adjacent to rhachis | R tenuispica |
| | Spreading around the rhachis | R insularis |
| 25 | FLOWER | Arranged distichously | 25A |
| | Arranged tristichously | patriae |
| | (Now Catopsis minimiflora ) | |
| 25A | SEPALS | and Floral bracts brown scaled to scattered | R flexuosa |
| | brown scales | |
| | and Floral bracts whitish scaled to | R multiflora |
| | glabrous, inflorescence tripinnate | |
| | and floral bracts whitish scaled to | R. domingos martinsis |
| | glabrous, inflorescence bipinnate | |
| 26 (11) | PLANT | Stemless | 29 |
| | With a stem | 27 |
| 27 | PLANT | Long stem,spike erect | 27A |
| | Short stem, Petals with toothed edges | crenulipetala |
| | appendaged | |
| | Short stem or stemless. Petals not tooth | 28 |
| | edged or appendaged | |
| 27A | LEAF | 8mm wide, narrow triangular, blades | reichenbachii |
| | recurving. Scape to 7 cm long | |
| | 2cm wide, 5cm long | peiranoi var. alba |
| | 2 cm wide, narrow lancelike, 10-30cm long | 27B |
| 27B | INFLORESCENCE | lax, leaves grey green. Plant not secund | buchlohii |
| | Sub globose, leaves grey, plant secund. | gardneri v. rupicola |
| | Petals white according to Leme( BSI J. 1987 p221) | |
| 28 | PRIMARY BRACTS | caudate but shorter than axillary spikes | confinis |
| | caudate attenuate, lower ones much | confinis v caudata |
| | exceeding axillary spikes | |
| | acute | 28A |
| 28A | SEPAL | To 1.4 cm long. Floral bract shiny red. | vernicosa |
| | Spike almost erect or spreading bent | |
| | Ca 1.5 cm long, Floral Bract green, sparsely | bonita |
| | hyaline-lepidote. Spike spreading | |
| | To 1.8 cm long. Floral bract red or green | lorentziana |
| | Spike widely spreading | |
| 29 | SCAPE | Very short | 39 |
| | Long, visible | 30 |
| 30 | PETAL | Long, thin, oar shaped, laxly hanging, | grandis |
| | greenish white, stamens visible, but not | |
| | longer than the petal. | |
| | Not hanging | 31 |
| 31 | PLANT | With thin grasslike leaves | 31A |
| | Not with thin grasslike leaves | 32 |
| 31A | INFLORESCENCE | Long and narrow | remota |
| | more or less globose | globosa forma alba |
| 32 | LEAF | Dense grey to silver grey scaled | 36 |
| | yellow green, shining with very fine scales | rosacea |
| | inflo to 10cm long, densely bipinnate | |
| | Green | 33 |
| 33 | FLORAL BRACT | Red | 38 |
| | Other colours | 34 |
| 34 | FLORAL BRACT | Other than wholely red or green | 35 |
| 35 | FLORAL BRACT | Bottom and middle red, top white | naundorffiae |
| | red/orange, flowering to 80cm high, inflo | truncata |
| | cylindric, bipinnate/tripinnate, 30cm long | |
| | spikes suberect, 3-4cm long | |
| | Reddish brown to tan | venusta |
| 36 (32) | FLORAL BRACT | Dense grey scales | didisticha |
| | Glabrous to a little lepidote | goyazensis |
| | Glabrous | 37 |
| 37 | LEAF SHEATH | Almost disc shaped, dark brown scales | bismarckii |
| | Not clearly developed, grey scaled | vernicosa |
| 38 (33) | SCAPE | erect | 38A |
| | hanging over | amicorum |
| 38A | SPIKE | 6 cm wide,velvet like, light red | dyeriana |
| | 1 cm wide,shiny red, inflo digitate, floral | vernicosa |
| | bracts imbricate | |
| | 2cm wide, 4cm long, inflo bipinnate, floral | singularis |
| | bracts lax | |
| 39 (29) | INFLORESCENCE | Thick, short,capitate | schreiteri |
| | Not thick, short, capitate | 40 |
| 40 | INFLORESCENCE | Erect | 40A |
| | hanging | 41 |
| 40A | PLANT | with pseudobulb, leaves narrow triangular | bismarkii |
| | not with pseudobulb | 40B |
| 40B | LEAF | ligulate, rounded & apiculate, scape very | abbreviata |
| | short, inflo digitate,spikes long stemmed | |
| | ligulate, scape very short, inflo bipinnate | selleana |
| | sometimes tripinnate at base, spikes to | |
| | 8cm long, usually at right angles | |
| | ligulate attenuate, scape to 8cm long | raackii |
| | inflo digitate, spikes very short stemmed | |
| | narrow to triangular, to 25cm long, grey/ | rusbyi |
| | green, scape to 12cm long, inflo distichous | |
| | branched | |
| 41 | INFLORESCENCE | With 3 - 7, short, dense,digitate | matudae |
| | compound spikes. | |
| | Spike 6 - 7 cm long, 1.5 cm wide, 2-4 flowering | |
| | ca. 9, long,thin,hanging laxly arranged | barthlottii |
| | compound spike. Spike 25 - 30 cm long, | |
| | 5mm wide, 20 - 30 flowering | |
| 42 (10) | INFLORESCENCE | One or two flowered spike | 42A |
| | Three or more flowered | 43 |
| 42A | LEAF | Arranged distichously | andicola |
| | Arranged in a whorl, narrow triangular | tenuifolia |
| | floral bracts red | |
| | Arranged in a whorl, very thin linear, | alvareziae |
| | grass-like, floral bracts green | |
| 43 | FLOWER | Arranged distichously on rhachis | 50 |
| | Arranged polystichously at bottom but | guelzii or pucaraensis |
| | distichously at top | See Uncle Derek Says |
| | Arranged polystichously | 44 |
| 44 | PLANT | With stem | 47 |
| | Stemless | 45 |
| 45 | FLORAL BRACT | Greenish brown | pohliana |
| | Pink red | 46 |
| | Orange Red, floral bracts exceeding | recuvifolia |
| | sepals | var. subsecundifolia |
| 46 | SCAPE | "Very short, masked by the leaves;" | osea |
| | Inflorescence dense, almost capitate, | (now stricta) |
| | few flowered | |
| | 5-7 cm long, curved, floral bracts densely | minasgeraisensis |
| | pruinose all over, coral red | |
| | ca 10 cm long, hanging inflorescence, | recurvifolia |
| | laxly flowered. Floral bracts only lepidote | |
| | towards tip | |
| 47 | SCAPE | Long, widely exceeds the leaves | 49 |
| | Not exceeding the leaves or a few (2 - 3cm) | 48 |
| 48 | SEPAL | Joined at the back, 7 mm high | 48A |
| | Plant with long stalk | |
| | Joined for a short way equally | osea |
| | high. Plant with short stalk | (Now stricta) |
| 48A | PETAL | Rippled, twisted, to 30mm long. | bergeri |
| | Sepals to 18 mm. | |
| | Smooth, to 20mm long. Sepals to 10mm long | tenuifolia |
| | As for tenuifolia but leaves 3-7cm long | pardoi |
| | blade involute, lower floral bracts green | |
| | or tinged red, sepals 0.8 cm long | |
| 49 | LEAF | Short (2 - 4 cm long) erect and hugging | burle-marxii |
| | the stem, floral bracts yellow-green | |
| | Over 5cm long | 49A |
| 49A | LEAF | secund, 5-6cm long | araujei |
| | floral bracts pink | |
| | Sometines subsecund, leafblades 12-30 cm | leucopetala |
| | Inflor lax, fl bracts greenish, rose-orange | |
| | at top | |
| | not growing to one side | 49B |
| 49B | FLORAL BRACTS | green, leaves 9-11 cm long, nearly straight | nuptialis |
| | or very slightly growing to one side | |
| | green, petals white, blades spatulate 3-5 | mereliana |
| | cm long | |
| | red, leaves to 20cm long, dense grey | milagrensis |
| | lepidote | |
| | white | aeranthos v alba |
| | Pale yellow | aeranthos v flava |
| 50 (43) | FLOWER | Arranged densely on rhachis | 59 |
| | Arranged laxly on the rhachis | 51 |
| 51 | SEPAL | Not over 2 cm long | 53 |
| | Over 2 cm long | 52 |
| 52 | SPIKE | 6 cm wide. Floral bract orange-yellow to | dyeriana |
| | light cinnabar red, leaves ligulate, green, | |
| | purple spotted | |
| | 4cm wide, 11cm long, leaves very narrow | truxillana |
| | triangular, 2cm wide at base,dense grey | |
| | lepidote | |
| | 2 cm wide. Floral bract red, leaves narrow | acosta-solisii |
| | triangular, 1cm wide at base, green | |
| 53 | PLANT | Stemless | 55 |
| | With stem | 54 |
| 54 | FLORAL BRACT | Red | 54A |
| | Green. Plant short stemmed | chiletensis |
| 54A | PLANT | Long stemmed. Floral bract pale cinnabar red | toropiensis |
| | Short stemmed. Floral bract reddish brown. | bagua- grandensis |
| | reddish brown | |
| 55 | FLORAL BRACT | Longer than the sepal. Flower opening wide. | 55A |
| | Shorter or equal to the sepal | 56 |
| 55A | FLOWER | Spaced 7 mm apart | triglochinoides |
| | Spaced 2 - 3 cm apart, whitewith yellow eye | dodsonii |
| 56 | FLORAL BRACT | Not keeled | cornuta |
| | Keeled to weakly keeled | 57 |
| 57 | RHACHIS | Hollowed on the side, therefore weakly | monadelpha |
| | winged | |
| | Angled | 58 |
| 58 | FLORAL BRACT | Twice as long as the internodes of the | narthecoides |
| | rhachis | |
| | Many times longer than the internodes. | scaligera |
| 59 (50) | PLANT | Thickened at the base, bulblike | 70 |
| | Not thickened at the base, bulblike | 60 |
| 60 | PLANT | With green leaves | 68 |
| | With grey or silver grey scaled leaves | 61 |
| 61 | FLORAL BRACT | Red or dark purple | 61A |
| | Green, yellowish straw colour, pink | 62 |
| | or reddish brown | |
| | Green, almost glabrous, 6 x 1.2cm | camargoensis |
| | Green at base, red at top. Leaves dull, light | barfussii |
| | grey | |
| | Dark purple, 3 - 3.5 cm long. | guasamayensis |
| | Sepals nerved. No scape. | (Now muhriae) |
| 62 | PETAL | 2 cm wide, Edges wavy and serrated | xiphioides |
| | 1.6 bm wide, edges wavy and serrated | lechneri |
| | looks like a white petalled T. lotteae | |
| | xiphioides with petals only 6-9 mm wide | xiphioides var minor |
| | xiphioides with stem up to 40 cm long | prolata |
| | Less than 2 cm wide, Edges not wavy, | 63 |
| | barely or weakly serrated | |
| 63 | PLANT | Long stem. | 63A |
| | Stem 5-15 cm long, Leaves few, sometimes | afonsoana |
| | distichous, dense grey tomentose | |
| | Scarcely a short stem | 64 |
| 63A | SCAPE | Conspicuous. Leaf short, wide to bent | diaguitensis |
| | backward | |
| | conspicuous. Inflor 5.0-7.5 cm long. Floral | incarnata |
| | bracts exceeding sepals | var margaritacea |
| | Inconspicuous. Leaf short, wide to bent upward | arequitae |
| 64 | SPIKE | 1.5 cm wide | 64A |
| | 2.5 cm wide | 64B |
| 64A | SPIKE | To 1.5 cm wide, scape straight, | |
| | spike flattened | lorentziana |
| | To 1.5 cm wide, scape bent, spike | |
| | oval shaped in cross section, floral bracts | boliviensis |
| | lepidote and apiculate. | |
| 64B | FLORAL BRACTS | glabrous, broadly obtuse, wine reddish | micans |
| | glabrous, broadly obtuse, yellowish at | gerd-muelleri |
| | base, purple red at apex | |
| 65 | PLANT | No stem, bottom almost bulb forming | hemkeri |
| | Floral bract dark red, grey scaled | |
| | No stem, slightly secund, dense rosette, | barrasoae |
| | floral bracts glabrous, sometimes a second | |
| | spike | |
| | With stem | 67 |
| 67 | PLANT | Long stemmed. | 67A |
| | Short stemmed. Leaf 1.8 cm wide. | bermejoensis |
| | Back sepals joined a short way | |
| 67A | LEAF | Thin, 5-8 mm wide, 10-15 cm long | caulescens |
| | Sepals pinkish | |
| | Narrow, 15 mm wide, 9 cm long. | muhriae |
| | Sepals light green. | (see also guasamayensis) |
| 68 (60) | PLANT | Long stemmed, floral bracts ca equalling | caulescens |
| | sepals | |
| | Short stemmed, floral bracts exceeding | dorisdaltoniae |
| | sepals | |
| | Stemless | 69 |
| 69 | FLORAL BRACT | 5 cm long | heterophylla |
| | 1.7 cm long | scaligera |
| 70 (59) | FLORAL BRACT | Red. Sepal asymmetrical, leaf blades | R crispa |
| | with undulate margins | |
| | red, sepal asymmetrical, leaf blades not | R seemannii |
| | undulating, flowers often secund upwards | |
| | seemannii but leaf blades strongly undulate | R pulchella |
| | coriaceous, a narrow bulbose rosette | |
| | Dark red, grey scaled. Sepal symmetrical. | hemkeri |
(B) PETAL - WHITE/ WHITISH