Plant Identification Michael G. Simpson Identification - associating an unknown entity with a known one. Known and unknown entities refer to classes, groups

Plant IdentificationMichael 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 IdentificationMichael 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 keysDichotomous key

Compare two contrasting statements:

couplet = two contasting leads

Dichotomous key1. 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.................................Lachnanthes1' 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





Polyclave keyList 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)

37 Leaves with pellucid or glandular dots or lines

38 Leaves with a ligule

39 Stipules absent

40 Stipules present (only the scars may be left)

41 Flowers solitary

42 Inflorescence a raceme, simple and monopodial

43 Inflorescence a spike, simple and monopodial

44 Inflorescence a corymb, simple and monopodial

45 Inflorescence an umbel, simple and monopodial

46 Inflorescence a fascicle, simple and monopodial

47 Inflorescence a head, simple and monopodial

48 Inflorescence simple and sympodial (cyme, dichasium etc.)

49 Inflorescence compound, sympodial or monopodial (panicle, thyrsus etc.)

50 Flowers bisexual

51 Flowers unisexual

52 Flowers actinomorphic

53 Flowers zygomorphic or irregular

54 Receptacle small (ovary superior)

55 Receptacle enlarged, united with the ovary, totally or partially covering it

56 Receptacle enlarged, totally or partially free from the ovary (super. to inf.)

57 Receptacle enlarged, conical or hemispherical (ovaries superior)

58 Disc present (annular or separate glands)

59 Disc absent

60 Perianth segments 0







67 Perianth segments more than 6

68 Perianth of similar segments

69 Perianth of calyx and corolla

70 Sepals 0 (incl. a cupular calyx without lobes)

71 Sepals 1

72 Sepals 2






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 pinnate-

netted, 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.







3) Specimen Comparison

Cryptantha pterocarya var. purpusii LINK: SDSU

http://www.sci.sdsu.edu/plants/cryptantha/taxa/C_pterocarya/var_purpusii/C_pterocarya_v_purpusii.html

http://www.sci.sdsu.edu/plants/cryptantha/taxa/C_pterocarya/var_purpusii/C_pterocarya_v_purpusii.html

Methods of identification1) Taxonomic keys

Dichotomous keyCompare two contrasting statements:





4) Image Comparison

Cryptantha racemosa LINK: CalPhotos

Methods of identification1) Taxonomic keys

Dichotomous keyCompare two contrasting statements:





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.

Documents

Plant Identification Michael G. Simpson Identification - associating an unknown entity with a known one. Known and unknown entities refer to classes, groups