DEPARTMENT OF BOTANY
LIANAS AND CLIMBING PLANTS OF THE NEOTROPICS
Key based on climbing mechanisms
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 (at least in young stages)
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
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, (> 50) inconspicuous, secondary veins, ~ perpendicular to the midvein; calyx and corolla
fused into a 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
not covered by an accrescent calyx
2. Leaves opposite; prehensile branches opposite, precociously developing before the leaves --Celastraceae
2. Leaves alternate; prehensile branches alternate, usually developing simultaneously with the leaves
3. Leaves simple
4. Petioles short, pulvinate at the base; flower zygomorphic; inner sepals petaloid; fruit syncarpous
or a samara --Polygalaceae
4. Petioles elongated, pulvinate at both ends; corolla actinomorphic, petals all equal;
fruits apocarpous --Menispermaceae
5. Stipules absent; flowers actinomorphic; inflorescence paniculate, racemose or spiciform;
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
--Blechnaceae (Lomaridium)
3. Sori dispersed on lower leaf surface; indusium absent
4. Leaflets margins serrate or serrulate; veins free or bifurcate --Lomariopsidaceae
4. Leaflet margins crenate; veins polygonal-areolate without free veinlets --Dryopteridaceae
1. Plant an anthophyte (flowering plant)
5. Leaves wanting, stems photosynthetic, with clusters of spines --Cactaceae
5. Leaves present; stems not as above
6. Leaves compound
7. Leaves alternate --Anacardiaceae
7. Leaves opposite --Bignoniaceae (Dolichandra)
6. Leaves simple
8. Leaves opposite
9. Corolla of free petals
10. Leaf venation acrodromous (5-9 main parallel veins) --Melastomataceae
10. Leaf venation pinnate
11. Leaves serrate; inflorescences with large, showy bracts --Hydrangeaceae
11. Leaves entire; inflorescences without large, showy bracts
12. Sepals with 2 large oil glands; petals yellow, clawed
--Malpighiaceae (Mascagnia vacciniifolia)
12. Sepals not bearing oil glands; petals cream or greenish, not clawed
13. Fruit indehiscent --Calophyllaceae
13. Fruit dehiscent --Clusiaceae
9. Corolla sympetalous
14. Stipules interpetiolar --Rubiaceae
14. Stipules wanting
15. Flowers with large, colorful bracts at base; stamens 4, staminodes 0; fruit capsular --Gesneriaceae
15. Flowers not bearing large bracteoles at base; stamens 2, staminodes 2; fruit a drupe
--Schlegeliaceae
8. Leaves alternate
16. Plant a monocot; stems with an atactostele
17. Flowers large, with well-developed perianth; central petal forming a labellum, solitary, in racemes
or umbels --Orchidaceae
17. Flowers minute, perianth small or wanting, produced in spikes
18. Leaves usually cordate, sagittate or truncate at base; stamens 3-6; ovary 1-3-locular --Araceae
18. Leaves attenuate at base; stamens 10-20; ovary 4-locular --Cyclanthaceae
16. Plant a dicot; stems with an eustele
19. Plant with milky sap --Moraceae (Ficus)
19. Plants with watery sap
20. Flowers naked or with minute perianth
21. Leaves with entire margins; stem’s cross section with wide rays; flowers naked, produced
in spikes; stems and leaves not stinging --Piperaceae
21. Leaves with dentate margins; stem’s cross section with inconspicuous rays; flowers with 4 minute
sepals, produced in cymes; young stems and leaves stinging --Urticaceae
20. Flowers with well-developed perianth
22. Inflorescence a capitulum with ray and disc flowers --Asteraceae
22. Inflorescence not a capitulum, flowers all similar
23. Inflorescences with large nectaries, these either in the center of inflorescence or on
the pedicels --Marcgraviaceae
23. Inflorescences not carrying nectaries
24. Leaves asymmetrical at base; flowers unisexual; corolla absent --Begoniaceae
24. Leaves symmetrical; flowers bisexual; corolla present
25. Corolla of free petals --Araliaceae
25. Corolla sympetalous
26. Ovary inferior; corolla not plicate --Ericaceae
26. Ovary superior; corolla plicate --Solanaceae
1. Plant a pteridophyte; leaf with indeterminate growth (> 2 m long), leaf rachis voluble (twining)
2. Sporangia produced on projections along the leaflet margin --Lygodiaceae
2. Sporangia produced on abaxial surface of fronds, covered by an elongated, linear indusium lateral
to the midvein --Blechnaceae (Salpichaena)
1. Plant a spermatophyte; leaves with determinate growth, leaf rachis if present not voluble
3. Leaves alternate
4. Plants with white latex
5. Leaves entire; corolla actinomorphic--Convolvulaceae (most genera)
5. Leaves serrate or denticulate; corolla bilabiate -- Campanulaceae (Siphocampylus)
4. Plants with clear latex or latex not visible
7. Leaves palmately compound; stipules lacking --Dioscoreaceae
7. Leaves variously compound (commonly trifoliolate), not palmate; stipules present --Fabaceae
8. Petioles pulvinate at both ends --Menispermaceae
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
12. Leaves pinnately veined
15. Leaves with entire or crenate margins
16. Stipules wanting
17. Corolla sympetalous
18. Fruit a capsule or leathery berry --Convolvulaceae
18. Fruit fleshy, a berry or a drupe
19. Fruit a berry with numerous seeds; corolla plicate; anthers poricidal or loculicidal--Solanaceae
19. Fruit a drupe, often with 4 pyrenes; corolla not plicate; anthers loculicidal
20. Stems commonly > 1 cm diam., solid; inflorescence a scorpioid cyme;
flowers not inserted on a large foliaceous bracteole; style with a single
round-pyramidal stigma --Heliotropiaceae
20. Stems slender (< 1 cm diam.), fistulose; inflorescence a corymbose cyme;
each flower inserted at the middle of a large leaf-like bracteole
(larger than the flower); style crowned by two stigmata --Ehretiaceae
17. Corolla wanting or petals free
21. Plant aromatic; flowers without perianth, produced in spikes --Piperaceae
21. Plant not aromatic, or with unpleasant smell; flowers with perianth, not produced in spikes
22. Plant with a pair of axillary, recurved thorns at the base of leaves; petals
and stamens numerous --Cactaceae (Pereskia)
22. Plant lacking thorns; petals wanting or petals and stamens 5-merous
23. Plant with strong disagreeable smell; flower lacking petals --Phytolaccaceae (Agdestis)
23. Plant without disagreeable smell; flowers with 5 petals
24. Stems fleshy, cross-sections with vascular elements divided in radial segments --Basellaceae
24. Stems 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
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)
28. Inflorescence otherwise
29. Flowers unisexual
30. Flowers actinomorphic, in cymes, spikes, racemes or pseudanthia;
ovary syncarpous; fruits capsular --Euphorbiaceae
30. Flowers zygomorphic, solitary; ovary apocarpous; fruit a berry
--Schisandraceae
29. Flowers bisexual
31. Petals unequal, one of them spurred --Violaceae
32. Petals equal, not forming a spur
32. Stamens numerous; bark exfoliating in thin, reddish brown,
rectangular plates --Dilleniaceae
32. Stamens 5; bark smooth or slightly rough, not exfoliating
33. Stems with successive rings of vascular tissue, producing a mucilaginous secretion; flowers lacking a nectary disc; fruit a drupe --Icacinaceae
33. Stems without successive growth of vascular tissue; flower with an annular nectary disc; fruit a capsule --Celastraceae (Celastrus)
3. Leaves opposite, verticillate or fasciculate
34. Leaves verticillate or fasciculate
35. Leaves fasciculate, with parallel venation; plant lacking white sap --Asparagaceae
35. Leaves verticillate, with pinnate venation; plant usually with white sap --Apocynaceae
34. Leaves opposite
36. Inflorescence a capitulum --Asteraceae
36. Inflorescence of racemose or paniculate cymes
37. Stipules present
38. 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
38. Petioles and leaf blades without glands; sepals without oil glands; petals not keeled; fruits
not samaroid
39. Corolla of unequal, free petals, one of them spurred; ovary superior; fruit a capsule --Trigoniaceae
39. Corolla sympetalous; ovary inferior; fruit a berry, capsule or drupe --Rubiaceae
37. Stipules wanting
40. Stems with successive production of vascular tissues
41. Stems producing a cream or white latex
42. "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
42. 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).
41. Stems not producing latex --Amaranthaceae
40. Stems without successive rings of vascular tissues
43. Stem cross section with interxylary phloem islands --Gelsemiaceae
43. Stem cross section with regular anatomy
44. Plant parasitic; in addition to twining branches climbing through the aid of stout epicortical roots equipped with haustoria -- Loranthaceae (Struthanthus)
44. Plants not parasitic; without epicortical roots or haustoria
45. Leaf venation acrodromous, with several main veins from base --Melastomataceae
45. Leaf venation pinnate or palmate, not acrodromous
46. Corolla of free petals, or absent
47. 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
47. 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
46. Corolla gamopetalous
48. Leaves compound
49. Stems woody; ovary superior; petioles not prehensile --Oleaceae
49. Stems herbaceous; ovary inferior (petioles sometimes prehensile) --Caprifoliaceae
48. Leaves simple
50. Flowers subtended by two, large bracteoles --Acanthaceae (Mendoncia, Thunbergia)
50. Flowers not subtended by large bracteoles
51. Calyx relatively large, spathaceous, slightly inflated --Orobanchaceae (Vellosiella)
51. Calyx not as above
52. Corolla gibbose (lower portion forming a large pouch) --Calceolariaceae
52. Corolla not gibbose
53. Inflorescences dichotomously branched cymes; placentation parietal --Gentianaceae (Bisgoeppertia)
53. Inflorescences not dichotomously branched; placentation axial
54. Ovary not lobed; style terminal --Verbenaceae
54. Ovary 4-lobed; style gynobasic --Lamiaceae
1. Scrambling fern; leaves rachides armed with prickles -- Lindsaeaceae (Odontosoria)
1. Scrambling flowering plant; plants armed with axillary or stipular spines, or with prickle
along stems or leaves
2. Inflorescence a capitulum --Asteraceae (Dasyphyllum)
2. Inflorescence not a capitulum (but inflorescence branches can have flowers grouped in heads)
4. Leaves opposite
5. Stems slender (~5 mm diam.), 2–4 m long; plant with straight axillary acicular thorns);
stipules absent --Acanthaceae (Oplonia)
5. Stems up to 15 cm in diam. and 20 m long; plant with axillary hook-shaped or
curved thorns; stipules interpetiolar
6. Leaves penninerved; axillary thorns hook-shaped; stipules large --Rubiaceae (Uncaria)
6. Leaves with acrodromous venation; axillary thorns curved (not hook-shaped);
stipules represented by an interpetiolar ochrea-like ridge --Loganiaceae
4. Leaves alternate
7. Leaves with serrate margins
8. Leaf with a pair of recurved stipular spines at the base; flowers unisexual; ovary
bicarpellate; fruit a fleshy drupe --Cannabaceae
8. Leaves without recurved stipular spines, sometimes armed with scattered prickles;
flowers bisexual; ovary 3-5-carpellate; fruit not a drupe
9. Flowers in axillary cymes; petals with an unguiculate, apical appendage;
fruit a schizocarp --Malvaceae (Byttneria)
9. Flowers in axillary fascicles; petals wanting; fruit a fleshy capsule --Salicaceae
7. Leaves with entire margins
10. Corolla sympetalous; anthers poricidal --Solanaceae (Solanum)
10. Corolla wanting
11. Calyx tubular
12. Stem’s cross section with regular anatomy; plant with short brachyblasts
that end on a sharp spine; anthers opening by a pair of hinged valves
--Lauraceae (Aiouea)
12. Stem’s cross section with interxylary phloem islands; plants with axillary,
recurved or straight thorns; anthers opening by longitudinal slits
--Nyctaginaceae
11. Calyx of free sepals
13. Stems commonly > 6 cm diam., with successive concentric rings of xylem
and phloem; plant often armed with a pair of small, recurved thorns at the
base of petiole -- Petiveriaceae (Sequieria)
13. Stems 2-6 cm diam., with regular anatomy; plant sometimes armed with axillary,
recurved or down pointing hooks (the remaining base of aborted shoots)
-- Hernandiaceae
14. Climbing palms; distal leaflets usually modified into reflexed hooks; inflorescence subtended
by a large, woody, spiny spathe --Arecaceae (Bactris, Desmoncus)
14. Leaflets not modified into hooks; inflorescences not subtended by a spathe
15. Leaves glandular punctate; fruit a capsule --Rutaceae
15. Leaves not glandular punctate; fruit not capsular
16. Stamens numerous; carpels numerous, coherent; fruits a syncarp of numerous,
minute, coherent drupes --Rosaceae
16. Stamens ca. 10; carpel solitary; fruit a legume --Fabaceae
1. Scrambling fern or fern ally
2. Plant climbing through 3-pinnate scrambling leaves that are up to 3 m long; leaves megaphyllous --Lindsaeaceae (Odontosoria)
2. Plant climbing through elongated, slender, brittle stems that are 5 to 10 m long; leaves microphyllous -- Selaginellaceae
1. Scrambling flowering plant
2. Plant a monocot
3. Flowers lacking perianth
4. Weak herbs with trigonous, solid stems--Cyperaceae
4. Wiry or sub-woody herbs with cylindrical, solid or hollow stems --Poaceae
3. Flowers with showy perianth
5. Plant a climbing palm --Arecaceae (Chamaedorea)
5. Plants herbaceous not a palm
6. Petals, blue, violet, pink or white; stamens 3; staminodes 3,
not petaloid --Commelinaceae
6. Petals whitish to pink; stamen 1; staminodes 5, petaloid or
modified into a hood --Marantaceae
2. Plant a dicot
7. Leaves compound
8. Leaves opposite --Bignoniaceae (Podranea, Tecoma)
9. Stipules present; fruit a legume -- Fabaceae
9. Stipules absent; fruit not a legume
10. Plant herbaceous or sub-woody 1-2.5 m long
11. Leaves bipinnate, ca. 60 cm long; corolla wanting; fruit an achene --Ranunculaceae (Thalictrum)
11. Leaves trifoliolate, < 15 cm long; corolla of 5, free, yellow petals; fruit capsular --Oxalidaceae
10. Plants woody > 3 m long; fruit a drupe or follicle
12. Leaflets crenate to serrulate; fruit a drupe --Anacardiaceae
12. Leaflets entire; fruit a follicle --Connaraceae
7. Leaves simple
13. Leaves opposite or verticillate
14. Inflorescence a capitulum --Asteraceae
14. Inflorescence not a capitulum
15. Corolla gamopetalous
16. Plant with white latex --Apocynaceae (Allamanda)
16. Plant with clear or no visible exudate
17. Stipule interpetiolar; ovary superior or inferior
18. Plant densely tomentose with whitish grey stellate hairs; stipules early
caducous; ovary superior --Scrophulariaceae
18. Plant with various indument but not as above; stipules caducous or persistent;
ovary inferior --Rubiaceae
17. Stipules absent; ovary superior
19. Fruit a capsule
20. Corolla bilabiate
21. Calyx of free sepals
22. Leaves often with epidermal cystoliths; capsule with hook placenta --Acanthaceae
22. Leaves lacking epidermal cystoliths; capsule without hook placenta --Calceolariaceae
21. Calyx gamosepalous, spathaceous --Orobanchaceae
20. Corolla actinomorphic
23. Inflorescences dichotomously branched cymes;
placentation parietal --Gentianaceae
23. Inflorescences not dichotomously branched;
placentation axial --Plantaginaceae
19. Fruit a drupe
24. Ovary semi-inferior --Viburnaceae
24. Ovary superior
25. Ovary, deeply 4-lobed; style gynobasic --Lamiaceae
25. Ovary not lobed; style terminal --Verbenaceae
15. Petals free or wanting
26. Leaf venation acrodromous or plinerved, with several main veins from base
27. Leaves 5-plinerved; stamens 40-50 per flower -- Hydrangeaceae (Philadelphus)
28. Leaves acrodromous; stamens 8 to 12 per flower
29. Ovary syncarpous; leaves petioled --Melastomataceae
29. Ovary completely or partially apocarpous; leaves sessile --Coriariaceae
26. Leaf venation pinnate
30. Leaves serrulate; flowers unisexual --Monimiaceae
30. Leaves entire; flowers bisexual
31. Stems with successive rings of vascular tissue;
fruit a circumscissile, membranous utricle --Amaranthaceae
31. Stems without successive rings of vascular tissue;
fruit indehiscent, a berry or a capsule
32. Plant with watery, inconspicuous or mucilaginous exudate
33. 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
33. Cross section of mature stems not as above; flowers actinomorphic; calyx forming a hypanthium; ovary inferior; fruit a berry or a dry pseudocarp
34. Exudate watery or not visible; stems without perimedular phloem; flowers solitary, pendulous; fruit a berry --Onagraceae
34. Exudate usually mucilaginous stems with perimedular phloem; flowers in spikes or racemes; fruit dry, indehiscent or dehiscent, 4- or 5-winged --Combretaceae
32. Plant with yellow or orangish exudate
35. Fruit indehiscent --Calophyllaceae
35. Fruit capsular --Clusiaceae
13. Leaves alternate
36. Plant producing milky sap; stipule deciduous, elongate, forming a
conical hood that protects the apical meristem; fruit a syconium --Moraceae
36. Plant with watery or milky sap; stipule if present, not as above
37. Anthers opening through a pair of upward hinged valves --Lauraceae
37. Anthers opening through longitudinal slits or poricidal
38. Corolla gamopetalous
39. Flowers produced in capitula --Asteraceae
39. Flowers in racemose or paniculate inflorescence
40. Plant with white latex --Campanulaceae
40. Plant with clear latex
41. Inflorescences pedunculate sub-dichasial or corymbose
cymes with flowers grouped in heads or flowers in axillary
glomerules --Cordiaceae
41. Inflorescence not as above
42. Inflorescence scorpioid cymes --Heliotropiaceae (Myriopus)
42. Inflorescence not a scorpioid cyme
43. Corolla plicate; stem cross section with perimedullary
phloem --Solanaceae
43. Corolla not plicate; stem cross section lacking perimedullary phloem
44. Calyx with 5 longitudinal ribs covered with stipitate glands;
fruit a valvate capsule with a single seed --Plumbaginaceae
44. Calyx not as above; fruit a berry with numerous seeds --Ericaceae
38. Corolla of free petals or wanting
45. Corolla wanting or early deciduous
46. Xylem with included islands of phloem --Nyctaginaceae
46. Xylem without included phloem
47. Flowers unisexual
48. Flowers produced in spikes; leaves usually aromatic;
xylem with wide rays --Piperaceae
48. Flowers in racemes, glomerules, or cyathia; leaves not aromatic;
xylem with narrow or inconspicuous rays -- Euphorbiaceae
47. Flower bisexual
49. Stipules forming an ochrea --Polygonaceae
49. Stipules absent
50. Stems with regular vascular anatomy
51. Inflorescence short racemes; ovary superior; stigmas
sessile, penicillate --Petiveriaceae (Trichostigma)
51. Inflorescence short to long dichasial cymes with flexuose
axes and swollen nodes; ovary inferior; inferior; stigma stalked,
capitate --Hernandiaceae
50. Stems with successive rings of vascular tissue
52. Fruit a circumscissile, membranous utricle; perianth of tepals;
stamens with filaments connate to form a short cup at the base,
these sometimes alternating with staminal appendages; style one
with bilabiate, capitate or 2–3-branched stigmas --Amaranthaceae
52. Fruit a capsule dehiscing from the apex toward the base; perianth
of calyx and of early deciduous corolla; styles 3-5, elongated with
terminal stigma --Stegnospermataceae
45. Corolla persistent
53. Flower with a nectar spur
54. Nectar spur formed by lower petals --Violaceae
54. Nectar spur formed by sepals --Tropaeolaceae
53. Flower lacking a nectar spur
55. Flower zygomorphic --Polygalaceae
55. Flower actinomorphic
56. Flower subtended by a bract that is modified into a nectary
of various shapes --Marcgraviaceae
56. Flower not subtended by a nectary
57. Ovary subtended by a gynophore --Capparaceae
57. Ovary sessile
58. Flower apocarpous, with numerous stamens --Annonaceae
59. Flower syncarpous; stamens 3–11
60. Petals bifid; inflorescence often born at apex
of petioles --Dichapetalaceae
60. Petals simple; inflorescence axillary or distal
61. Flower unisexual --Griseliniaceae
61. Flowers bisexual
62. Petals cucullate, enveloping the opposite
stamen --Rhamnaceae
62. Petals not cucullate
63. Calyx forming a large hypanthium
64. Plant without stinging trichomes; ovary superior;
petals unguiculate, much shorter than
the calyx --Lythraceae
64. Plant with stinging trichomes; ovary inferior;
petals sessile or unguiculate, as long as the calyx
--Loasaceae
63. Calyx not forming a hypanthium
65. Petals with an unguiculate apical appendage --Malvaceae
65. Petals lacking an unguiculate apical appendage
66. Petals cordiform, yellow; fruit an acropetally
dehiscent capsule --Ochnaceae
66. Petals lanceolate, white; fruit a drupe
67. Stamens 5 or 10; staminodes absent; fruit with
an accrescent calyx at base --Erythropalaceae
67. Stamens 3; staminodes 6, bifid; fruit without an
accrescent calyx at base --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