Download PowerPoint Presentation - Chapter 15 Plant Identification

Plant Identification
Michael G. Simpson
Identification - associating an unknown entity
with a known one.
Known and unknown entities refer to classes,
groups of individuals delimited by features.
Plant Identification
Michael G. Simpson
Diagnostic characterization (diagnosis)
= all features that distinguish an entity from all
other entities.
Identification = determining if diagnosis of
unknown falls within the diagnosis of a known.
Methods of identification
1) Taxonomic keys
Dichotomous key
Compare two contrasting statements:
couplet = two contasting leads
Dichotomous key
1. Fertile stamens 3 or 1 (Subfamily Haemodoroideae)
2. Ovary superior
3. Fertile stamen 1........................................................................Pyrrorhiza
3' Fertile stamens 3
4. Corolla actinomorphic
5. Inflorescence a simple raceme; functional carpel 1; ovule 1; style subterminal....Barberetta
5’ Inflorescence an elongate thyrse with lateral monochasial cymes; functional carpels 3;
ovules 20-30 per carpel; style terminal...........................................Xiphidium
4' Corolla zygomorphic
6. Stamens unequal, the 2 latero-posterior anthers reduced; ovules 3-4 per carpel......Schiekia
6' Stamens equal; ovule 1 per carpel...............................................Wachendorfia
2' Ovary inferior
7. Ovule 1 per carpel........................................................................Dilatris
7' Ovules 2 or more per carpel
8. Ovules 2 per carpel; perianth glabrous...............................................Haemodorum
8' Ovules 5-7 per carpel; perianth abaxially tomentose.................................Lachnanthes
1' Fertile stamens 6 (Subfamily Conostylidoideae)
9. Flowers actinomorphic; perianth not splitting along mid-anterior line
10. Perianth glabrous to glabrate.........................................................Phlebocarya
10' Perianth lanate to tomentose
11. Perianth lanate; trichomes simple to sparsely branched, white-whitish; anthers with broad,
apical connective appendage......................................................Tribonanthes
11' Perianth tomentose, trichomes dendritic, yellow, whitish, reddish, pink, orange, or purplish;
anthers without broad, apical connective appendage
12. Flowers pendulous; perianth reddish to pink-orange................................Blancoa
12' Flowers generally ascending; perianth usually yellow or whitish, rarely orange
to purplish....................................................................Conostylis
9' Flowers zygomorphic; perianth tube splitting along mid-anterior line
13. Ovule 1 per carpel; perianth trichomes black...........................................Macropidia
13' Ovules >1 per carpel; perianth trichomes red, yellow, orange or green................Anigozanthos
Methods of identification
1) Taxonomic keys
Dichotomous key
Compare two contrasting statements:
couplet = two contasting leads
Polyclave key
List presence / absence of all features
Polyclave key
1 Woody plants (excl. suffrutices)
2 Herbaceous plants (incl. suffrutices)
3 Aquatic plants, leaves floating or submerged
4 Chlorophyll absent (parasites or saprophytes)
5 Bulb present (monocots only)
6 Milky juice present
7 Spiny stems or leaves
8 Tendrils present
9 Cladodes or phyllodes (modified branches or petioles)
10 Hairs glandular
11 Hairs stellate (also 2-armed, branched and tufted)
12 Hairs stellate (not 2-armed, branched and tufted)
13 Hairs 2-armed or t-shaped, non-glandular
14 Hairs branched
15 Hairs tufted, non-glandular
16 Hairs peltate or scale-like
17 Hairs vesicular or bladder-like
18 Hairs stinging
19 Cystoliths present (dicots only)
20 Leaves opposite or verticillate
21 Leaves alternate (excl. distichous monocots)
22 Leaves distichous (monocots only)
23 Leaves equitant (e.g. Iris)
24 Leaves not compound
25 Leaves compound
26 Leaves pinnately compound (4 or more leaflets)
27 Leaves ternately compound (3 leaflets)
28 Leaves palmately compound (4 or more leaflets)
29 Venation pinnate or hardly visible in leaves or leaflets (incl. no. 30)
30 Venation invisible or leaves 1-nerved (monocots only)
31 Venation longitudinal in leaves or leaflets (incl. 3-nerved leaves)
32 Venation palmate in leaves or leaflets
33 Leaves or leaflets with entire margin (without any lobes or teeth)
34 Leaves or leaflets lobed or divided
35 Leaves or leaflets dentate, serrate, crenate, etc.
36 Epidermis of leaf papillose (dicots only)
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Leaves with pellucid or glandular dots or lines
Leaves with a ligule
Stipules absent
Stipules present (only the scars may be left)
Flowers solitary
Inflorescence a raceme, simple and monopodial
Inflorescence a spike, simple and monopodial
Inflorescence a corymb, simple and monopodial
Inflorescence an umbel, simple and monopodial
Inflorescence a fascicle, simple and monopodial
Inflorescence a head, simple and monopodial
Inflorescence simple and sympodial (cyme, dichasium etc.)
Inflorescence compound, sympodial or monopodial (panicle, thyrsus etc.)
Flowers bisexual
Flowers unisexual
Flowers actinomorphic
Flowers zygomorphic or irregular
Receptacle small (ovary superior)
Receptacle enlarged, united with the ovary, totally or partially covering it
Receptacle enlarged, totally or partially free from the ovary (super. to inf.)
Receptacle enlarged, conical or hemispherical (ovaries superior)
Disc present (annular or separate glands)
Disc absent
Perianth segments 0
Perianth segments 1
Perianth segments 2
Perianth segments 3
Perianth segments 4
Perianth segments 5
Perianth segments 6
Perianth segments more than 6
Perianth of similar segments
Perianth of calyx and corolla
Sepals 0 (incl. a cupular calyx without lobes)
Sepals 1
Sepals 2
Methods of identification
1) Taxonomic keys
Dichotomous key
Compare two contrasting statements:
couplet = two contasting leads
Polyclave key
List presence / absence of all features
2) Written Description
Tecoma capensis (Thunb.) Lindl., Cape-Honeysuckle (native to S. Africa). Bignoniaceae.
Plant a shrub, up to ca. 5 m tall. Root a woody taproot with numerous lateral roots. Stems (aerial) highly and sympodially branched by abortion of terminal
inflorescence meristems, branches basally inclined. Bark brown, smooth to minutely furrowed, lenticels orbicular to vertically elliptic with raised borders,
ca. 1-2 mm wide. Twigs terete, minutely puberulent. Pith solid, circular in outline. Fruit scars (of infructescence) raised, circular, typically at junction
of two, lateral branches. Leaf scars slightly raised below, orbicular with truncate apex. Vascular bundle scar U-shaped. Buds in leaf axils small (ca. 2
mm long), with outer two scales in a plane tangential to stem axis, scales valvate, lance-ovate and strongly cup-shaped, densely pubescent; terminal buds
naked, elongate, to 5 mm long. Leaves 10-12 cm long, imparipinnate, petiolate, exstipulate, evergreen, cauline, opposite-decussate, divergent to inclined,
and planar to recurved. Petiole green, terete to canaliculate, 1-3 cm long. Leaf outline elliptic. Leaflets 9 [11], opposite. Lateral leaflets elliptic to widely
elliptic, subsessile, 15-17 mm long, 10-14 mm wide, base attenuate to obtuse, sometimes oblique, margin usually proximally entire and serrate to crenate
distally, apex acuminate (caudate), tip minutely mucronulate, Apical leaflet widely elliptic, usually petiolulate (petiolule green, narrowly winged, 3-13
mm long) 24-30 mm long, 15-20 mm wide, cuneate, entire at base and distally serrate to crenate, acute to accuminate, mucronulate. All leaflets pinnatenetted, midvein and secondary veins sunken above and raised below, mostly glabrous but with arachnose trichomes near abaxial vein junctions,
mesophyllous. Inflorescence a terminal thyrse with several bracteate units of simple dichasia or of solitary flowers, the latter often with two abortive,
lateral flower buds or with two sub-basal bracts (indicative of a vestigial dichasium). Flowers perfect, ca 50 mm long, ca 25 mm wide, opposite,
appressed, recurved, zygomorphic, pedicellate. Pedicel ca 7 mm long, terete. Bract 1 subtending each unit of inflorescence, 1-5 mm long, lanceolate,
mucronulate. Bractlets 2, sub-basal, subtending lateral flowers if simple dichasium present. Perianth biseriate, dichlamydeous. Calyx synsepalous,
actinomorphic, ca 5 mm long. Calyx lobes acute, mucronulate, ca 1 mm long. Corolla sympetalous, orange, zygomorphic, salverform-bilabiate with
enlarged throat, ca 45 mm long, recurved, inner surface pubescent. Corolla lobes 5 (2 posterior, 2 lateral, and 1 anterior), oblong to elliptic, apices
rounded to emarginate, 7-12 mm long, 5-7 mm wide, inclined to divergent and recurved relative to floral axis. Stamens 4 fertile, uniseriate, filamentous,
epipetalous, didynamous, alternipetalous, exserted, apostemonous. Staminodium 1, medio-posterior, reduced, up to ca 10 mm long. Filaments (of fertile
stamens) terete, yellow-orange, 35-40 mm long. Anthers versatile, basifixed, longitudinally and introrsely dehiscent (downwardly dehiscent at maturity),
ca. 3 mm long, thecae divergent. Pollen orange. Gynoecium syncarpous. Perianth/Androecial position hypogynous. Ovary superior, green, 4-5 mm
long, narrowly obloid, glabrous. Carpels 2. Locules 2. Placentation parietal-axile. Ovules many. Styles 1, terminal, apically recurved, purple-brown.
Stigmas 2, ovate, divergent to appressed. Nectary dark maroon, doughnut-shaped, surrounding ovary base. Fruit a brown loculicidal capsule (with
persistent replum), narrowly oblong, up to ca. 1 cm wide and 6 cm long. Seeds flat, with surrounding, yellowish, translucent wing, ca. 15 mm long and 8
mm wide (including wing), seed body roughly orbicular, ca. 6 mm in diameter.
FLORAL FORMULA: K (5) C (5) A 2+2+1staminode G (2), superior.
Methods of identification
1) Taxonomic keys
Dichotomous key
Compare two contrasting statements:
couplet = two contasting leads
Polyclave key
List presence / absence of all features
2) Written Description
3) Specimen Comparison
Cryptantha pterocarya var. purpusii LINK: SDSU
Methods of identification
1) Taxonomic keys
Dichotomous key
Compare two contrasting statements:
couplet = two contasting leads
Polyclave key
List presence / absence of all features
2) Written Description
3) Specimen Comparison
4) Image Comparison
Cryptantha racemosa LINK: CalPhotos
Methods of identification
1) Taxonomic keys
Dichotomous key
Compare two contrasting statements:
couplet = two contasting leads
Polyclave key
List presence / absence of all features
2) Written Description
3) Specimen Comparison
4) Image Comparison
5) Expert Determination
Ask him: Dr. Jon Rebman (SD)
Expert on Plants of San Diego County and Baja California,
& Cylindropuntia spp.
Identification
Always check and double-check an
identification.
Taxon identified could be new to a region.
Identification could be negative, indicating a
taxon new to science.