e-Key v3 - Key to Heliantheae Genera
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Interactive keys to the identification of seed plants of southern Africa using keys based on plant morphology.
  • Key after Wild: 1 (1967) and Hilliard: 290 (1977)
Backtrack a
  • Capitula unisexual
002
b
  • Capitula bisexual
002
Backtrack a
  • Involucral bracts of male capitula connate
  • Ffemale capitula 1-flowered
  • Cypsela clasped by female involucre which bears 4-6 spines
* Ambrosia
b
  • Involucral bracts of male capitula free
  • Female capitula 2-flowered
  • Cypsela clasped by female involucre bearing hooked spines
* Xanthium
Backtrack a
  • Florets of disc sterile
002
b
  • Florets of disc fertile (or only innermost sterile)
002
Backtrack a
  • Cypselas tightly clasped by one of the inner involucral bracts which developed hooked spines
  • Pappus 0
* Acanthospermum
b
  • Cypselas clasped by an involucral scale and 2 lateral, concave, involucral paleae
  • Pappus of 2 recurved awns clasping the margin of the cypsela
* Parthenium
Backtrack a
  • Receptacular paleae ± flat not clasping cypselas
002
b
  • Receptacular paleae ± conduplicate and clasping or enfolding cypselas
002
Backtrack a
  • Involucral bracts quite free, the inner merging gradually into the receptacular paleae
  • Leaves simple
002
b
  • Involucral bracts of the inner row connate at base, outer row fewer and mostly smaller or narrower
  • Leaves variously divided
002
Backtrack a
  • Pappus 0
  • Lamina of ray florets golden yellow
* Guizotia
b
  • Pappus present
  • Lamina of ray florets white, cream or yellow
002
Backtrack a
  • Pappus of densely plumose bristles
* Tridax
b
  • Pappus of scales, persistent or caducous
002
Backtrack a
  • Pappus of 2 scales, soon caducous, cypselas winged
  • Large yellow rays
* Coreopsis
b
  • Pappus of several scales, cypselas not winged
  • Very small, white rays
* Galinsoga
Backtrack a
  • Leaves alternate
* Chrysanthellum
b
  • Leaves opposite
002
Backtrack a
  • Ray florets yellow, golden, orange or 0
Bidens
b
  • Ray florets white, pink, lilac or red
* Cosmos
Backtrack a
  • Involucral bracts 4, in 2 rows of opposite pairs, leafy
  • Flower heads axillary, sessile or subsessile
Enydra
b
  • Involucral bracts 3 to many, but not in 2 rows of opposite pairs and leafy
  • Capitula not sessile or subsessile and axillary
002
Backtrack a
  • Inner involucral bracts embracing fertile ray cypselas
  • Involucral bracts spathulate and densely glandular
* Sigesbeckia
b
  • Inner involucral bracts not embracing outermost cypselas
002
Backtrack a
  • Leaves alternate as a rule
  • Receptacular paleae cymbiform, clasping cypselas and produced above into a ± tubular neck
  • Ray florets 0 or neuter
Sclerocarpus
b
  • Leaves opposite, sometimes alternate above
002
Backtrack a
  • Cypselas surmounted by a distinct, often lacerate cupule
  • Additional pappus bristles present or 0
002
b
  • Cypselas without pappus or with pappus of various kinds, but not a cupule
002
Backtrack a
  • Ray florets sterile (although style and stigmas rarely present)
  • All cypselas ± alike, bilaterally convex or obscurely 4-angled
Aspilia
b
  • Ray florets fertile (with style and stigmas and producing mature cypselas
  • Outer cypselas ± triquetrous
002
Backtrack a
  • Laminas conspicuous, yellow
  • Leaves lobulate
  • Petioles short
  • Capitula long-pedunculate
  • Cypselas tuberculate with caducous aristae
* Sphagneticola
b
  • Laminas small, white
  • Leaves simple
  • Petioles slender
  • Capitula subsessile or shortly pedunculate
  • Cypselas minutely transversely rugulose with persistent barbellate awns
Blainvillea
Backtrack a
  • Ray florets persistent
  • Annual herbs up to 0.6 m tall. unbranched
  • Leaves narrowly oblong-ovate
* Zinnia
b
  • Ray florets not persistent
002
Backtrack a
  • Cypselas 4-sided
  • Capitula large and showy with orange-red or yellow ray florets
  • Apex of peduncles becoming very thick
* Tithonia
b
  • Cypselas ± compressed or, if not noticeably compressed, peduncles not swollen above
002
Backtrack a
  • Receptacular paleae obovate, truncate-emarginate and caudate-spinescent at apex
  • Perennial shrubs up to 6 m tall with white rays
* Montanoa
b
  • Receptacular paleae not caudate-spinescent
002
Backtrack a
  • Disc florets deep purple, at least above
* Helianthus
b
  • Disc florets not purple
002
Backtrack a
  • Disc florets white
  • Receptacular paleae very narrow and often setiform
* Eclipta
b
  • Disc florets not white, ± yellowish
002
Backtrack a
  • Cypselas thick or angular, not compressed, pubescent at apex, not winged or margined
* Melanthera
b
  • Cypselas ± compressed, winged or with a hyaline cartilaginous margin
002
Backtrack a
  • Cypsela with broad, irregular margin
  • Lamina of ray florets 10 mm long or more
* Verbesina
b
  • Cypsela with hyaline, cartilaginous margin
  • Ray florets ± 1.3 mm long or 0
Spilanthes

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