1. Tendrils derived from the apical or basal portion of leaf
2. Tendril solitary, derived from apical portion of leaf blade
3. Leaf midvein prolonged into a spiral tendril; inflorescence a capitulum with ray and disc
flowers --Asteraceae(Mutisia)
3. Leaf apex prolonged into a circinate tendril-like tip; inflorescence a panicle with laterally compressed spikelets
-- Poaceae(Melica)
2. Tendrils in pairs, arising from the petiole or leaf sheath --Smilacaceae
1. Tendrils entirely substituting one or more leaflets
4. Tendril substituting the distal leaflet; leaves trifoliolate and opposite; stem’s cross sections with 4 or
multiple of 4 phloem wedges --Bignoniaceae
4. Tendril substituting two or more distal leaflets or pinna; leaves pinnately compound, alternate;
stem’s cross section without phloem wedges
5. Leaves bipinnate; tendrils representing two opposite, distal pinna --Fabaceae(Entada)
5. Leaves once pinnate; tendrils representing several, alternate, distal leaflets
6. Plant herbaceous, stipules present; corolla with standard, keel and wing petals --Fabaceae (Vicia)
6. Plants woody or semi-woody; stipules absent; corolla sympetalous
7. Inflorescence a dichasial cyme or flowers solitary; all flowers similar;
fruit a capsule --Polemoniaceae (Cobaea)
7. Inflorescence a capitulum with ray and disc flowers; fruit a cypsela Asteraceae(Mutisia)
1. Tendril and inflorescences opposite to the leaves --Vitaceae
1. Tendrils axillary, lateral to a leaf, or part of the inflorescence; inflorescence axillary or distal
2. Tendrils circinate
3. Leaves compound
4. Leaves imparipinnate; tendrils always paired, often at the base of the flowering portion of the inflorescence
--Sapindaceae
4. Leaves paripinnate; tendrils solitary, not produced at the base of inflorescence --Fabaceae (Senegalia)
3. Leaves simple (sometimes deeply bilobed)
5. Leaves opposite; xylem with included islands of phloem -- Loganiaceae
5. Leaves alternate; xylem not containing islands of phloem
6. Stipules connate around the stem to form a tubular ochrea; tendrils formed at distal ends of inflorescence
--Polygonaceae(Antigonon)
6. Stipules not forming a tubular ochrea; tendrils not as above
7. Leaves commonly retuse at apex to deeply bilobed (sometimes resembling two separate leaflets); stem
cross-section with a cross-shaped medulla --Fabaceae (Schnella)
7. Leaves not retuse nor deeply bilobed; stem cross-section with a cylindrical medulla
8. Inflorescences axillary, cymose; peduncles elongate, bearing two triads and a hook-like,
circinate tendril; flowers 4-merous, with a tubular laciniate corona and a short
androgynophore; fruit a capsule --Passifloraceae(Ancistrothyrsus)
8. Inflorescence axillary or terminal, spicate, racemose or paniculate thyrses, tendrils solitary
at the end of short branches or associated to the inflorescences; fruit a septicidal,
trigonous capsule --Rhamnaceae
2. Tendrils helicoidal or filiform
9. Tendrils axillary-lateral (usually at 90° angle with petiole), mostly branched; stems mostly fleshy,
herbaceous; cross-sections commonly with axial vascular elements divided in radial segments by
broad strips of ground tissue --Cucurbitaceae
9. Tendrils axillary, commonly unbranched; stems herbaceous to woody; cross-sections with abundant
wide rays within the xylem and most species with phloem wedges --Passifloraceae
1. Leaves with numerous, secondary and tertiary parallel veins; calyx and corolla fused into tubular perianth;
drupes covered by an accrescent calyx --Thymelaeaceae
1. Leaves with reticulate or scalariform tertiary venation; calyx and corolla not fused, petals free; fruits
without an accrescent calyx
2. Leaves and prehensile branches opposite, precociously developing before the leaves --Celastraceae
2. Leaves and prehensile branches alternate, usually developing simultaneously with the leaves
3. Leaves simple
4. Flower zygomorphic; inner sepals petaloid; fruit syncarpous or a samara --Polygalaceae
4. Corolla actinomorphic, petals all equal; fruits apocarpous --Menispermaceae
3. Leaves compound
5. Stipule absent; flowers actinomorphic produced in racemes; fruit a single or several follicles --Connaraceae
5. Stipules present; flowers zygomorphic or if actinomorphic, produced in capitula; fruit a legume --Fabaceae
1. Inflorescence a capitulum with ray and disc flowers --Asteraceae (Hidalgoa)
1. Inflorescence cymose with all flowers similar, or flowers solitary
2. Leaves simple, alternate
3. Leaves peltate; calyx with a long spur --Tropaeolaceae
3. Leaves not peltate; calyx not bearing a spur
4. Flower formed by a tubular perianth, deep pink, large (> 2 cm long), constricted below the middle;
fruits an ellipsoid or ovoid anthocarp --Nyctaginaceae(Belemia)
4. Flower with distinct calyx and corolla; corolla gamopetalous, bilabiate; fruit capsular
(Mexico, Guatemala, Honduras) --Plantaginaceae (Lophospermum)
2. Leaves compound, opposite
5. Corolla wanting; stamens numerous; gynoecium of several free carpels; bark shaggy peeling off in
fibrous strands --Ranunculaceae
5. Corolla sympetalous; stamens 4; gynoecium syncarpous; bark smooth to rough but not peeling off in
fibrous strands
6. Plant herbaceous (stems 3-8 mm diam.); flowers minute (2-5 mm long); ovary inferior
--Caprifoliaceae (Valeriana)
6. Plant woody (stems 1-3 cm diam.); flower large (> 3 cm long); ovary superior --Bignoniaceae (Perianthomega)
1. Plant a pteridophyte
2. Fronds monomorphic (fertile and sterile fronds similar in shape and size)
--Oleandraceae
2. Fronds dimorphic (fertile fronds significantly smaller than the sterile ones)
3. Sori in elongate-linear groups that are lateral to the midvein; indusium entire, elongate
8. Petioles not pulvinate or if pulvinate, only at base
9. Leaves with numerous, secondary veins that are parallel to the midvein
10. Leaves resupinate or semi-resupinate, not sheathed at base; perianth formed by tepals of similar
coloration; ovary semi-inferior; seeds with orange-red sarcotesta --Alstroemeriaceae
10. Leaves not resupinate, with sheathing or clasping bases; perianth of sepals and petals, usually
of different coloration; ovary superior; seeds not sarcotestal --Commelinaceae
9. Leaves palmately veined (plinerved, subtriplinerved or acrodromous) or with pinnate secondary venation
11. Plant scabrid, glochidiate, scabrid-glochidiate with stinging (splinter or glandular) hairs --Loasaceae
11. Plant not as above
12. Leaves palmately veined (plinerved, subtriplinerved or acrodromous)
13. Flower large (often > 2 cm long), formed by an enlarged inflated calyx (an utricle);
corolla wanting; stem with axial vascular elements in radial segments --Aristolochiaceae
13. Flowers not as above; stem not as above
14. Leaves plinerved or acrodromous; stems herbaceous or wiry; stem cross-section
with collateral vascular bundles scattered in the ground tissue; flowers formed
by 6 distinct or connate tepals in 2 whorls-- Dioscoreaceae
14. Leaves subtriplinerved; stems woody or subwoody; stem cross-section with xylem
forming a continuous large cylinder traversed by narrow or inconspicuous rays;
flowers with well develop calyx and corolla, 5-merous -- Malvaceae
22. Plant without disagreeable smell; flowers with 5 petals
23. Sepals with 2 large, abaxial oil glands; fruits of 3 samaroid mericarps
--Malpighiaceae(Barnebya)
23. Sepals not glandular; fruit a berry or an utricle
24. Stem woody, cross-section with successive rings of xylem and phloem
25. Stem cross-sections with discontinuous rings of vascular tissue;
fruit a circumscissile membranous utricle --Amaranthaceae
25. Stem cross-sections with continuous rings of vascular tissue;
fruit a fleshy or leathery berry --Polygalaceae
24. Stems fleshy, cross-sections with vascular elements divided
in radial segments --Basellaceae
16. Stipules present
26. Stipules forming an ochrea; petals wanting --Polygonaceae
26. Stipules, free, not forming an ochrea; petals present
27. Leaves crenate; petals entire at the apex, cucullate,
enveloping the stamens; inflorescences axillary or terminal
racemose or paniculate thyrses -- Rhamnaceae(Berchemia)
27. Leaves entire; petals bifid at the apex, not enveloping the stamens;
inflorescences dichotomously branched, often adnate to the petiole,
fasciculate, corymbose or paniculate cymes --Dichapetalaceae
15. Leaves with serrate, lobed, or dentate margins
28. Inflorescence a capitulum --Asteraceae(Leonis, Pseudogynoxys)
37. Petioles and/or leaf blade usually with prominent glands; sepals usually with a pair of oil
glands; petals clawed; fruits usually a samaroid schizocarp --Malpighiaceae
37. Petioles and leaf blades without glands; sepals without oil glands; petals not keeled; fruits
not samaroid
38. Corolla of unequal, free petals, one of them spurred; ovary superior; fruit a capsule
--Trigoniaceae
38. Corolla sympetalous; ovary inferior; fruit a berry, capsule or drupe --Rubiaceae
36. Stipules wanting
39. Stems with successive production of vascular tissues
40. Stems producing a cream or white latex
41. "Inflorescences" (strobili) axillary, paniculate, with whorled spike-like units (cones) bearing
verticels of naked "flowers" subtended by cupular or annular involucral collars;
leaf blades with areoles lacking free veinlets --Gnetaceae
41. Inflorescences axillary and/or terminal, frequently 2 per node, a dichasial cyme or a thyrse,
with 5 to 30 large gamopetalous flowers, subtended by bracts; leaf blades with areoles
containing free veinlets --Apocynaceae (Odontadenia). .
39. Stems without successive rings of vascular tissues
42. Stem cross section with interxylary phloem islands --Gelsemiaceae
42. Stem cross section with regular anatomy
43. Plant parasitic; in addition to twining branches climbing through the aid
of stout epicortical roots equipped with haustoria -- Loranthaceae(Struthanthus)
43. Plants not parasitic; without epicortical roots or haustoria
44. Leaf venation acrodromous, with several main veins from base --Melastomataceae
44. Leaf venation pinnate or palmate, not acrodromous
45. Corolla of free petals, or absent
46. Pubescence never of stinging or glochidiate hairs; woody lianas; stem
cross-section with perimedular phloem and usually with mucilaginous exudate;
cortex usually with layers of sclereids; inflorescence racemose or
paniculate -- Combretaceae
46. Pubescens of stinging, glochidiate or scabrid hairs; herbaceous vines; stem
cross-section without a perimedular phloem, lacking mucilaginous exudate;
cortex lacking bundles of sclereids; inflorescence of
dichasiate cymes or flowers solitary --Loasaceae
45. Corolla gamopetalous
47. Leaves compound
48. Stems woody; ovary superior; petioles not prehensile --Oleaceae
48. Stems herbaceous; ovary inferior (petioles sometimes prehensile) --Caprifoliaceae
47. Leaves simple
49. Flowers subtended by two, large bracteoles --Acanthaceae (Mendoncia, Thunbergia)
32. Stems with successive rings of vascular tissue;
fruit a circumscissile, membranous utricle --Amaranthaceae
32. Stems without successive rings of vascular tissue;
fruit indehiscent, a berry or a capsule
33. Plant with watery, inconspicuous or mucilaginous exudate
34. Cross-section of mature stems with 4(5) conspicuous
equidistant phloem wedges; flower zygomorphic;
calyx not forming a hypanthium; ovary superior;
fruit a septicidal, trigonous capsule;
seeds covered by long, wooly hairs -- Trigoniaceae
34. Cross section of mature stems not as above; flowers
actinomorphic; calyx forming a hypanthium; ovary inferior;
fruit a berry or a dry pseudocarp
35. Exudate watery or not visible; stems without perimedular
phloem; flowers solitary, pendulous; fruit a berry
--Onagraceae
35. Exudate usually mucilaginous stems with perimedular
phloem; flowers in spikes or racemes; fruit dry, indehiscent
or dehiscent, 4- or 5-winged --Combretaceae
58. Stipules elongated, early caducous, leaving numerous
conical colleters along the scar that extends around the stem;
flowers 5-merous; sepals of same size; stamens 10;
anthers dehiscing by a single apical pore
--Ochnaceae
58. Stipule early caducous or absent, colleters absent;
flowers 3-5-merous; sepals unequal; stamens numerous,
anthers dehiscing along longitudinal slits --Dilleniaceae
66. Fruit totally enclosed by a fleshy accrescent
(not reflexed) calyx -- Olacaceae
1. Leaves absent or reduced to scales
2. Stems yellow to orangish without visible chlorophyll; flowers 4- or 5-merous with distinctive calyx and corolla;
corolla inside with fimbriate or crenulate, membranous, infrastaminal scales at base of tube, anthers
dehiscing longitudinally -- Convolvulaceae (Cuscuta)
2. Stems green or yellowish green; flowers of 6 tepals in two series, not bearing scales internally; anther dehiscing
by a pair of hinged valves --Lauraceae(Cassytha)
1. Leaves fully developed with coriaceous or fleshy blades -- Loranthaceae