The Process of Identification |
The steps involved in conclusively identifying a plant, when you have no prior knowledge of its identity, involve:
• observing the plant’s characteristics, particularly its floral structure
• working through an appropriate botanical key—you will need to know whether the plant is growing wild or is in cultivation because most references are restricted in content along these lines
• checking your keyed answer against an authoritative source—this could include herbarium reference specimens, accurately named photographs or drawings, and detailed descriptions such as are found in floras.
Equipment
Minimum requirements: a single-sided razor blade; 2 darning needles, pushed into corks for handles; a pair of tweezers; a 10× hand lens, or a lens or magnifying glass mounted on a stand. Refinements: 1 or 2 pairs of jeweller’s forceps with fine points; a binocular dissecting microscope. Mounted darning needles can be further sharpened on an oil stone.
Choosing the flower to look at
As a means of gaining experience in the process of identification a good place to start may be to examine a flower that is illustrated in this book and then compare your observations with the drawings and captions. This means that you will already know the plant’s name which can help to guide your path through a key. It is also a good idea to start with a large flower that has a simple structure, to get the feel of the process of dissection. Beware of horticultural forms with multiple petals, such as roses, carnations and some fuchsias, and avoid daisies at first. Also, be aware that species which are usually bisexual may at times produce unisexual flowers. Similarly, cultivars derived from species with unisexual flowers such as Lomandra (Matrush, Pl. 11g–k) may be propagated by tissue culture and the resulting plants may be all of one sex. Attempt to collect both sexes of unisexual-flowered species if possible.
Some plant species are very variable, so it is unwise to assume that all flowers on a plant, or in a population, will be identical. Minor variations may not be important, such as colour differences, or an extra petal on some flowers, but try to select representative flowers. Stamens commonly open in sequence, and the early ones may fall before the last one opens, so if you are in doubt about the number of stamens, look at a bud. On the other hand, older flowers often show the ovary structure more clearly. Collect fruits, if available, and note habit and leaf characters.
Interpreting what you see
Remove the flower parts carefully and lay them out. Note the following points:
| Perianth | number of whorls (one or two), or parts arranged spirally presence of sepals as well as petals |
| Calyx | number of sepals (they may be very small) free or united other features (hairs, dissected margins...) |
| Corolla | number of petals free or united other features (colour, hairiness—internal or external...) |
| Androecium | number of stamens (1–10 or numerous) free or united epipetalous or joined to the receptacle other features (appendages, hairiness ...) presence of staminodes |
| Gynoecium | carpels free—number of carpels (1–10 or numerous) carpels united—ovary superior or inferior number of carpels—decide by noting: style simple or branched stigma simple or lobed number of loculi in the ovary (cut a T.S.)—if one loculus, then number of placentas placentation (cut a T.S. and L.S., see also Fig. 21; Pls. 1f, g, 3f, g, 15d, e) |
Fig. 20 Using a hand lens: hold the lens close to the eye and bring the plant up until it is in focus.
Fig. 21 Flower sections: cutting a flower to examine its structure
The floral formula for this hypothetical example is K5 C5 A5 G(5). Similar sections have been used in most of the Figures in Chapter 8. See also Pls. 1f, g, 3f, g.
Transverse section (T.S.)
Identify the ovary, hold the flower by the stalk and make horizontal cuts. It is easier to see the loculi if you cut a thin slice, and examine that with a lens as it sits on the edge of the razor blade. If the flower is small and the ovary superior, it may be better to hold the flower by the petals and start cutting near the base of the calyx.
Longitudinal section (L.S.)
Examine the outside of the ovary for signs of its structure. Often there will be lines or creases indicating the positions of the septa and loculi. Try to cut through the centre of at least one loculus. If the cut is a little off centre it may be difficult to interpret what you see.
When cutting a half flower, and the flower is actinomorphic, it may be cut in any plane, but often a carefully judged half flower will also give a good section of the ovary. If the flower is zygomorphic, choose the plane that will result in more or less equal halves. Lay the flower on its side and cut carefully but firmly (Fig. 21).
Using keys
You will now need a book (usually a flora) or internet site, appropriate for your region, that includes a key to the families of plants. The reference list includes some available for the Australian flora, and those by Bailey (1949), Spencer (1995–), and Cullen et al. (2011) that are useful for garden plants.
Keys provide a method of identifying a plant by the process of elimination. They are usually quite artificial in the sense that most keys do not take account of real relationships, but only of characteristics that will separate one species from another. The first key steps in floras usually separate non-flowering plants such as ferns and conifers from the Flowering Plants. Assuming that your sample is a Flowering Plant the next steps will continue to divide up the species into groups using mutually exclusive character pairs such as ‘perianth of one whorl / perianth of two whorls’, ‘petals free / petals united’, or ‘ovary superior / ovary inferior’. These pairs are termed couplets, and each of the character statements in a couplet is a lead. The leads are mutually exclusive because a plant matching one of the leads cannot simultaneously match the other.
In existing published keys the Flowering Plants will often first be separated into Monocots and Dicots. Due to changes in classification (see Chapter 6), keys in electronic form on the internet are increasingly unlikely to include the Dicots as a recognised group. Keys will then systematically divide the main groups into families, genera and species.
In practice, there may be three or four leads in some couplets—convenient for the writer and not necessarily adding complication. The two common types of keys, bracketed and indented, differ only in layout. In bracketed keys the leads of a couplet are set out together. Using the character pairs mentioned before, a possible bracketed key may be:
An indented key using the same character pairs would be set out as follows:
Both methods split the families into eight groups with the following combinations of characters:
Thus, in the first couplet of the bracketed key, a flower in group A would take the first lead, and progress to couplet two, indicated by the number in the right-hand column. In this couplet, the specimen again matches the first lead and progresses to couplet four. At couplet four the correct choice, ovary superior, leads to group A.
In an indented key to a large number of families or genera, the first and second leads of a couplet may not be on the same page, so check this before proceeding. In our example, the two opposing leads in each couplet are marked with the same number; sometimes letters or other symbols are used, for example A and AA, A and A’ etc. A plant in group G would take the second lead of couplet one. From here the next step is to couplet five. The second lead again applies and in couplet seven the first choice leads to group G.
Points to note
It is important to read both or all leads in the couplet before deciding which one to follow. Not all couplets are as clear-cut as our examples at the beginning of the previous section on using keys, and further on in a key couplets tend to become more complex.
It is useful to write down the steps you have taken as you go through a key. It is then easier to check your route if an error is made. If you do not arrive at a satisfactory answer, it is likely that the mistake is yours, but it is important to note that keys are not infallible. Sometimes a species varies so much that it is a real challenge to cover the whole range when writing a key. Most keys are written for the plants of a particular region, and some weeds and most garden plants may not be included. Occasionally such a plant may key out easily to an incorrect answer, so it is important to check identifications against written descriptions or illustrations. Numerous plant images are now on the internet, which can be a very useful source of information. When accuracy is important, however, it is perhaps unwise to accept the identity of internet images without checking against an authoritative source.
The members of some families show considerable variation of form and it may not be possible to ‘key them out’ as a single group. Thus, a family may be brought out several times, as some groups of genera follow different routes. Similarly, in a key to genera, a particular genus may appear more than once.
Computers and keys
An ever-increasing amount of plant identification literature is becoming available on the internet. Institutions such as Herbaria or Botanical Gardens are making their floras, previously published in hard copy, available via their websites. The botanical keys presented in this computer context may not differ in any material way to those in previously printed form, although sometimes it is possible to switch the layout from indented to bracketed with a simple click. It may also be possible to access images or other information to quickly check the accuracy of progress through a key.
Another type of key, necessarily restricted for use on a computer, is available for certain plant groups. These electronic keys, sometimes called multiple access keys, are similar in principle to traditional printed keys but have one significant advantage—the user is not required to start from the beginning and then work through the key following a particular order of couplets. Information concerning the characteristics of the sample to be identified can be entered into the computer in any order. As this information is entered, the computer systematically searches its memory of the features of the various plant groups, and rejects those that do not match. This leaves a progressively smaller number of possible ‘matches’.
Ideally there will be only one final answer, but if the information entered is limited (for example if your sample does not have flowers and you are relying on vegetative features only) then the computer will provide a list of possible answers. This is an advantage over traditional keys which are limited by the quality of the specimen to be identified. For example, if your sample has flowers but no fruit, and the next couplet in the key requires information about the fruit, then progress is either halted, or you must follow both leads in the hope that the correct path will become clear later in the key.
Remember that the user must still correctly interpret the features of the sample to be identified. Electronic keys often provide guidance, usually in the form of small diagrams, explaining the use of descriptive terms. Possible additional features can be included such as the ability to select the ‘best’ characteristics to enter which will most effectively divide remaining groups, and the option to view the similarities and differences between selected groups.
Presumably because of the large amount of work required to enter all the data, the number of multiple access keys available to date is relatively small. Examples include keys to Victorian eucalypts and daisies, Australian wattles, eucalypts, and rainforest plants.
Sample bracketed key to species illustrated in this book
The following key has been written to cover only those species illustrated here in Figures 22–132 and Plates 1–34 (although to conserve space, often only the generic names are given in the key). It is intended to serve several purposes — as a practice tool for working with keys, as a means of introducing identifying features of various groups, and to allow an unknown plant to be matched with an illustration if this is possible.
Within the leads, an attempt has been made to use so-called ‘key characters’. Thus the key may work correctly for other species in a genus, allowing a correct generic identification even if the species is not illustrated here, but this is not guaranteed. For species with unisexual flowers, the key assumes that both sexes are available. To simplify the key, some species with unusual floral or vegetative features are briefly described here first, and not subsequently included in the key.
• Inflorescences small (c. 5 mm diameter); flowers unisexual, very reduced, borne within a cup-like structure; perianth absent; male flowers several, each of 1 stamen; female flower one, of just a stalked, trilocular ovary exserted from the ‘cup’Euphorbia (Fig. 78; Pl. 18a, b)
• Inflorescences more or less spherical, with unisexual flowers enclosed completely within the hollow rounded axisFicus (Pl. 17a–c)
• Plants tiny (c. 1 mm long), aquatic, without roots, floating on the water surface; flowers seldom producedWolffia (Pl. 8a, b)
• Plants leafless; stems segmented, succulent; flowers immersed in stem or branchlet apicesSalicornia (Fig. 102), Tecticornia (Pl. 26g, h)
• Trees, apparently leafless, the leaves reduced to whorls of small teeth at each branchlet node; flowers unisexualAllocasuarina (Pl. 17d–g)
• Twining parasitic perennials, apparently leafless; flowers c. 2 mm diam., mostly in short spikes; fruits globular, fleshyCassytha (Pl. 6e–i)
1. Inflorescences made up of individual flowers (sometimes small, or crowded in heads, but not in spikelets) 2
1. Inflorescences made up of spikelets — short axes bearing small, sessile flowers mostly obscured by one or more closely placed bracts (Grasses and Sedges, Pls. 12a–i, 13)159
2. Perianth present, of one or more series of parts4
2. Perianth absent3
3. Plants herbaceous; inflorescence of male (above) and female flowers on a fleshy axis, subtended by a large bractArisarum (Pl. 8f, g), Zantedeschia (Pl. 8c–e)
3. Plants shrubby; inflorescence of female flowers clustered in upper axilsAtriplex cinerea (Pl. 27e–g)
4. Perianth parts all completely united into one or two caps shed as the flower opensEucalyptus (Figs. 84–88)
4. Perianth parts free or united, not all shed as one or two caps as the flower opens (in Richea, only the petals fall as a cap)5
5. Plant parasitic, with drooping, rather brittle branchlets; inflorescence pendulous, umbellate with the main branches bearing groups of 3 or 4 flowers; ovary structure obscureAmyema pendula (Pl. 24f, g)
5. Plant a clump-forming, dioecious, herbaceous perennial; leaves narrow-linear, to c. 70 cm long; flowers more or less tubular, to c. 4 mm long; stamens 6, the inner 3 joined to the petals; carpels 3, unitedLomandra confertifolia (Pl. 11g–k)
5. Plant not entirely matching the previous two leads6
6. Perianth of 1 whorl, or if more, the parts all similar7
6. Perianth of 2 whorls, which differ in colour and/or shape and/or size (sepals and petals; sometimes only one petal differs in the orchids; the calyx much reduced and rim-like in Rhododendron)70
7. Small, erect, subshrub to c. 50 cm high, in heathlands and woodlands; flowers unisexual; in small clusters on angular, often leafless stems; tepals 4–5; carpels 3, unitedAmperea xiphoclada (Pl. 18c–g)
7. Plant not entirely as above8
8. Ovary inferior or almost so9
8. Ovary superior31
9. Inflorescence a head of small flowers (florets) surrounded by one or more series of bracts (Figs. 116, 121; Pl. 32b–e), or a compound head of small partial heads, (each partial head made up of several florets surrounded by bracts, Fig. 126; Pl. 33l) (Daisies)10
9. Inflorescences various, but not a head surrounded by an involucre of bracts, nor a compound head23
10. Heads ligulifloral, with florets all asymmetrical, each corolla produced on one side as a strap-shaped ligule (Pl. 32i)11
10. Heads discoid, radiate or compound, with florets all symmetrical (the corollas tubular, Fig. 121c; Pl. 33d), or some corollas tubular and some ligulate12
11. Flowering stem unbranched; receptacle naked between the floretsTaraxacum officinale (Figs. 124, 125)
11. Flowering stem usually branched; receptacle bearing membranous scales between the floretsHypochoeris radicata (Pl. 32 f–k)
12. Heads compound (Fig. 126; Pl. 33l)13
12. Heads simple14
13. Leaves alternate; compound heads globose to c. 3.5 cm diameterPycnosorus globosus (Pl. 33k, l)
13. Leaves opposite; compound heads usually broadly ellipsoid, to c. 1 cm diameterCalocephalus citreus (Figs. 126, 127)
14. Heads with all florets tubular (rarely some florets without corollas)15
14. Heads with central tubular florets surrounded by one or more rows of ligulate florets19
15. Involucral bracts brightly coloured, stiffly papery, radiating out from the central part of the headXerochrysum bracteatum (Fig. 119)
15. Involucral bracts herbaceous or scarious, mostly erect around the head16
16. Glabrous, (semi-)aquatic, herbaceous perennial; leaf bases sheathing; heads more or less hemisphericalCotula coronopifolia (Pl. 33j)
16. Variably hairy, terrestrial annual or perennial; leaf bases not sheathing17
17. Perennial; leaves linear-lanceolate, entire; involucral bracts fringed, in several seriesLeptorhynchos squamatus (Figs. 122, 123)
17. Annual or perennial; leaves more or less oblong to oblanceolate, to obovate, simple with margins lobed to more or less pinnate; involucral bracts not fringed18
18. Robust, greyish-green, cultivated perennial with large, more or less globose heads to 10 cm diameterCynara scolymus (Pl. 33 m)
18. Small, green annual; heads cylindrical, to c. 3 mm diameterSenecio vulgaris (Figs. 120, 121)
19. Pappus of hairs or bristles, or absent21
20. Involucral bracts in one row, unitedTagetes (Figs. 116, 117)
20. Involucral bracts in several rows, freeGalinsoga (Pl. 33a–e)
21. Disc florets functionally male; pappus absent; fruits fleshyChrysanthemoides monilifera (Pl. 33f–h)
21. Disc florets bisexual; pappus present; fruits dry22
22. Plant annual; ligules usually purpleSenecio elegans (Pl. 32b–e)
22. Plant an herbaceous perennial; ligules yellowPodolepis jaceoides (Pl. 33i)
22. Plant a woody shrub or tree; ligules whiteOlearia argophylla (Fig. 118)
23. Perianth parts in whorls of three24
23. Perianth parts in a whorl of five28
24. Stamens free or united, but not united with the style or stigma25
24. Stamen and stigma united into a central columnThelymitra (Pl. 9g)
25. Stamens three26
25. Stamens six27
26. Anthers aligned on one side of the flowerGladiolus (Pl. 10a–e)
26. Anthers evenly placed, each opposite an outer tepalLibertia (Fig. 30)
27. Tepals pink; leaves absent at flowering timeAmaryllis (Pl. 11a–c)
27. Tepals white with a green mark near the apex; leaves present at flowering timeLeucojum aestivum (Fig. 34)
28. Inflorescence a raceme or small panicle; carpels 3Pomaderris (Fig. 74)
28. Inflorescence a compound umbel of numerous flowers; carpels 229
29. Bracts and bracteoles absent from the inflorescence; flowers yellow or greenish-yellow30
29. Bracts and bracteoles present; flowers usually whiteDaucus carota (Pl. 34)
30. Ultimate leaflets < 1 mm wide; fruit 4–7 mm longFoeniculum vulgare (Fig. 132)
30. Ultimate leaflets > 1 mm wide; fruit to c. 3 mm longPetroselinum crispum (Pl. 5a–c)
31. Trunk stout, to c. 3 m high, bearing a dense terminal crown of linear leaves; flowers borne in a dense terminal spike-like inflorescence up to about 2 m longXanthorrhoea australis (Pl. 10 i, j)
31. Plants not combining all the above features32
32. Perianth in two whorls of three, or two whorls of two segments33
32. Perianth in one whorl of four or five segments48
33. Perianth in two whorls of two segmentsLaurus nobilis (Pl. 7f–i)
33. Perianth in two whorls of three segments34
34. Trees; stamens in three whorls of three35
34. Tufted or rhizomic herbs or herbaceous climbers; stamens in two whorls of three36
35. Flowers c. 10 mm diameter, in axillary racemesPersea (Pl. 7j–l)
35. Flowers 3–4 mm diameter, in small paniclesCinnamomum (Pl. 7a–e)
36. Staminal filaments hairy (sometimes only towards the base), and/or swollen below the anthers, or anthers with basal appendages37
36. Filaments and anthers without hairs, swellings or appendages40
37. Plants tufted; leaves basal38
37. Plants with leafy aerial stems; leaves distichousStypandra glauca (Pl. 10h)
38. Leaves terete, hollow; ovary obscured by dilated, hairy filament bases; stigma 3-lobedAsphodelus fistulosus (Pl. 10f, g)
38. Leaves more or less flat (or creased along the midline); ovary visible between filaments; stigma undifferentiated39
39. Filaments finely hairy; anthers without appendages; leaves distichousThelionema caespitosum (Fig. 31)
39. Filaments glabrous; anthers with hairy basal appendages; leaves encircling the stem, not distichousArthropodium strictum (Fig. 36)
40. Inflorescence umbellate41
40. Inflorescence spike-like, or paniculate, or flowers solitary or in small cymes42
41. Robust, clump-forming, leafy perennial; inflorescence subtended by two bracts; flowers numerousAgapanthus praecox (Figs. 34–5)
41. Slender, renascent herb with one or two leaves; inflorescence subtended by as many bracts as flowers; flowers 2–9Burchardia umbellata (Pl. 8l)
42. Plants tufted; leaves mostly basal, or reduced to basal sheaths43
42. Plants with leafy aerial stems (apparent leaves in fact cladodes in Asparagus)44
43. Leaves few, acute; flowers few; tepals blueChamaescilla (Fig. 32)
43. Leaves reduced to basal sheaths; flowers numerous; tepals mostly greenish, tinged reddish-brown (fading to straw-coloured)Juncus sarophorus (Pl. 12j–l)
44. Leaves reduced to very small scales subtending linear, leaf-like cladodes to c. 1.5 cm long, three from each node; flowers c. 5 mm diameter, whiteAsparagus aethiopicus (Pl. 11d–f)
44. Leaves not reduced, > 3 cm long; flowers > 8 mm diameter45
45. Renascent bulb- or corm-forming perennials; flowers one or few in a terminal raceme or spike-like inflorescence46
45. Rhizomic or scrambling perennials; flowers axillary, solitary or few in small cymes47
46. Flowers usually unisexual, to c. 2 cm diameter; tepals white, usually with a narrow, transverse, purple bandWurmbea dioica (Fig. 23)
46. Flowers bisexual, trumpet-shaped, to c, 15 cm long; tepals white, the midline tinged greenish or purplish externallyLilium (Pl. 9a–e)
47. Climbers; leaf blades ending in a tendril; flowers solitary, to c. 8 cm diameter; tepals reddish to orangeGloriosa superba (Pl. 8j, k)
47. Plants with upright simple stems from a rhizome, not climbing; leaf apices acute, without tendrils; flowers to c. 2.5 cm diameter, in small cymes; tepals pale pinkTripladenia cunninghamii (Pl. 8h, i)
48. Tepals four49
48. Tepals five58
49. Plant a climber; flowers white, unisexual; stamens and carpels numerousClematis microphylla (Fig. 42)
49. Shrubs or trees; flowers usually bisexual, colour various; stamens 2– 4; carpel 1 (or apparently so in Pimelea)50
50. Small shrub to c. 50 cm high; leaves opposite; flowers in terminal heads; floral tube present; stamens twoPimelea glauca (Fig. 101)
50. Shrubs or trees; leaves alternate; inflorescences various; floral tube absent; stamens four (including possible staminodes)51
51. Leaves compound52
51. Leaves simple53
52. Upright or spreading shrub to c. 1.5 m; leaves digitately divided into 3–5 terete lobes; flowers one or few together at branch apicesAdenanthos terminalis (Fig. 43)
52. Tree to 30 m; leaves pinnate, with 10–25 leaflets which are further lobed or divided; flowers numerous in one-sided racemesGrevillea robusta (Figs. 48–9)
53. Flowers whitish and two-lipped, or yellow and actinomorphic; fruit indehiscent54
53. Flowers zygomorphic, colour various; fruit a follicle55
54. Flowers whitish, two-lipped, numerous in terminal panicles; fruit dryConospermum mitchellii (Figs. 46–7)
54. Flowers yellow, actinomorphic, solitary in leaf axils; fruit a drupePersoonia juniperina (Fig. 51)
55. Flowers 4–6 in small axillary clusters; valves of fruiting follicle solid and woodyHakea decurrens (Figs. 52–3)
55. Flowers numerous in dense spike-like inflorescences, or few or many in terminal racemes; fruiting valves hollow56
56. Shrub or small tree to c. 10 m high; flowers yellow in dense spikelike inflorescencesBanksia marginata (Figs. 44–5)
56. Shrubs, usually bushy, to c. 2 m high; flowers in racemes, usually a combination of red, pink, greenish or cream57
57. Leaves linear, 2-4 cm long, sharp-pointed; flowers up to c. 10 per racemeGrevillea rosmarinifolia (Fig. 50; Pl. 3a)
57. Leaves more or less oblong, 3–10 cm long, 1–4 cm wide, usually toothed or lobed, the lobes sharply pointed; flowers numerous (usually c. 20 or more) per racemeGrevillea aquifolium (Pl. 3b)
58. Stellate hairs present, at least on branchlets and/or flowers; loculi of ovary three59
58. Stellate hairs absent; loculi one or five61
59. Leaves more or less oblanceolate, c. 2–6 mm long; flowers white, solitary or in clusters of two or threeCryptandra amara (Fig. 73)
59. Leaves narrow-oblong, to lanceolate or ovate, > 10 mm long; flowers pink or purplish, in racemes or small panicles60
60. Leafy stipules present; tepals rather thin and somewhat paperyThomasia petalocalyx (Fig. 100)
60. Stipules absent; tepals thicker, not paperyLasiopetalum behrii (Pl. 22f, g)
61. Tree to 35 m; flowers bright red in loose axillary panicles; fruits follicles, up to five per flowerBrachychiton acerifolius (Pl. 22a–e)
61. Herbs or shrubs; flower colour various but not bright red; fruits indehiscent or utricles62
62. Leaves pinnate, stipulate; stigma much-branchedAcaena (Fig. 70)
62. Leaves simple, exstipulate; stigmas simple (usually extending over two or three styles or style-branches63
63. Perianth herbaceous, often greenish, sometimes tinged with pink, sometimes bearing tiny bladder-like hairs (Pl. 26b) that may collapse (Pl. 26e) forming a mealy covering64
63. Perianth scarious, often whitish, usually glabrous69
64. Leaf blades flat; plants usually bearing tiny bladder-like hairs that may collapse forming a mealy covering65
64. Leaf blades terete or nearly so; plants glabrous or hairy but not with bladder-like hairs67
65. Upright, weedy, herbaceous annual of wasteland and roadsides; flowers bisexual and female; fruit small, dry, not enclosed within bracteolesChenopodium album (Pl. 26a, b)
65. Bushy, dioecious (or sometimes monoecious) perennials of coastal situations; fruit fleshy and deep red, or more or less dry and enclosed within two enlarged bracteoles66
66. Leaf blades glossy green above; male flowers small but individually evident; fruits fleshy, deep redRhagodia candolleana (Pl. 26c–e)
66. Leaf blades silvery to pale grey; male flowers in very dense clusters (individual flowers not obvious)Atriplex cinerea (Pl. 27e–g)
67. Fruiting perianth dry, prominently winged, the whole fruit up to 1 cm diameterMaireana triptera (Pl. 27b)
67. Fruiting perianth fleshy or herbaceous, up to c. 6 mm diameter68
68. Small, rounded, glabrous shrub to c. 70 cm high; fruiting perianth herbaceous to somewhat fleshy, about 2 mm diameterSuaeda australis (Pl. 27c, d)
68. Low, spreading or erect, variably hairy shrub to 1.5 m high; fruiting perianth fleshy, green, yellow or red, to 6 mm diameterEnchylaena tomentosa (Pl. 26f)
69. Leaves opposite; flowers in dense axillary clustersAlternanthera denticulata (Pl. 27k–m)
69. Leaves alternate; flowers in dense spike-like inflorescences, terminal and in upper axilsAmaranthus powellii (Pl. 27h–j)
70. Plants shrubs or trees; leaves bipinnate or reduced to phyllodes; flowers usually yellow, borne in heads, spikes or racemes; stamens numerous, much longer than petals; carpel one71
70. Plants not combining all of the above features72
71. Leaves bipinnate; flowers with short stalks, in axillary racemesParaserianthes lophantha (Pl. 14a, b)
71. Leaves bipinnate or more often reduced to phyllodes; flowers sessile, in spikes or heads (that may then be arranged in racemes or panicles)Acacia (Figs. 58–62; Pl. 14c–j)
72. Ovary superior73
72. Ovary inferior137
73. Petals free74
73. Petals (if not all, at least some) united103
74. Flowers zygomorphic (not strongly so in Senna)75
74. Flowers actinomorphic76
75. Tree to 35 m tall; leaves 30–60 cm long; flowers 4–5 cm long; sepals unitedCastanospermum australe (Pl. 15f–i)
75. Bushy shrub to c. 2 m high; leaves 3–6 cm long; flowers up to c. 1.5 cm long; sepals freeSenna (Figs. 56–7; Pl. 15a–e)
76. Carpel singlePrunus (Fig. 72; Pl. 3c–g)
76. Carpels 2 or more and free, (if apparently united, then > 40 in a central column)77
76. Carpels united, less than c. 1583
77. Leaves succulent78
77. Leaves not succulent79
78. Upright, soft-wooded shrub; stamens 5Crassula ovata (Pl. 1)
78. Herbaceous perennial; stamens 10Sedum spectabile (Fig. 55)
79. Plants herbaceousRanunculus repens (Pl. 2a–c)
79. Plants trees or shrubs80
80. Plants trees81
80. Plants shrubs82
81. Leaf blades with several pointed lobes; individual fruitlets wingedLiriodendron tulipifera (Pl. 6a–d
81. Leaf blades entire; individual fruitlets not wingedMagnolia (Fig. 22)
82. Flowers hypogynous; petals yellowHibbertia (Fig. 54; Pl. 2d, e)
82. Flowers perigynous; petals whiteSpiraea thunbergii (Pl. 2 f, g)
83. Petals 3; flowers bisexualArthropodium strictum (Fig. 36)
83. Petals 4; flowers bisexual84
83. Petals 5 (each sometimes deeply notched), if rarely petals 4 then flowers unisexual88
84. Plants herbaceous85
84. Plants woody trees or shrubs86
85. Sepals 2; petal colour various; fruit a poricidal capsulePapaver (Pl. 4a–g)
85. Sepals 4; petals yellow; fruits narrowly cylindrical, dehiscing by valvesBrassica (Pl. 23)
85. Sepals 4; petals white; fruits compressed, the apex broadly notched, dehiscing by valvesCapsella bursa-pastoris (Pl. 24a–e)
86. Leaves compound, glandular dots often visible (Pl. 4h); carpels 487
86. Leaves simple, glands absent; carpels 2Tetratheca (Figs. 76–7; Pl. 4l)
87. Stamens 4; disc 4-lobed (Fig. 98)Zieria arborescens (Figs. 97–8)
87. Stamens 8; disc entire (Fig. 92d)Boronia (Fig. 92; Pl. 4h, i)
88. Petals small, opposite the 5 stamens, either pale and hooded over the anthers, or dark-coloured and gland-like below the filaments89
88. Petals obvious, alternating with the stamens (or stamens sometimes 10 or more, or fewer than 5)91
89. Petals hooded over the anthers, alternating with calyx lobes at the top of the whitish floral tubeCryptandra amara (Fig. 73)
89. Petals dark-coloured, below the filaments90
90. Leafy stipules present; tepals rather thin and somewhat paperyThomasia petalocalyx (Fig. 100)
90. Stipules absent; tepals thicker, not paperyLasiopetalum behrii (Pl. 22f, g)
91. Flowers unisexual; stamens numerous, united in a solid central column; carpels 3; bushy usually monoecious shrub with opposite, linear leaves to 3.5 cm longRicinocarpos pinifolius (Fig. 79)
91. Flowers usually bisexual; stamens 10 or fewer or, if numerous, then either free, or united and the staminal column hollow and enclosing the style; plant habit various92
92. Stamens united in a central column around the style93
92. Stamens free96
93. Plant a tree to c. 15 m high; flowers pink, c. 5 cm diam., axillaryLagunaria patersonia (Pl. 21a–d)
93. Plant a shrubs or herb94
94. Annual herbs usually < 1 m high; leaf blades orbicular to reniform; flowers in small axillary clustersMalva (Pl. 21e–g)
94. Perennial shrubs usually > 1.5 m high; leaf blades ovate (apex pointed); flowers solitary in leaf axils95
95. Flowers c. 5 cm long; petals erect, overlappingMalvaviscus arboreus (Fig. 99; Pl. 21i)
95. Flowers to c. 17 cm diam.; petals widely spreadingHibiscus (Pl. 21h)
96. Plants herbaceous97
96. Plants shrubs or trees or climbers99
97. Petals entire, bright red-pink; stamens 10; leaves (and whole plant) with a covering of whitish woolly hairsSilene coronaria (Pl. 25a–e)
97. Petals entire, white; stamens 5; upper surfaces of leaf blades with long-stalked glandular hairsDrosera hookeri (Pl. 24h)
97. Petals deeply notched, white; stamens 5 or fewer; leaf blades variously hairy or glabrous but not entirely as above98
98. Styles 3; capsule opening via 6 valves or teethStellaria (Pl. 25j, k)
98. Styles 5; capsule opening via 10 teethCerastium (Pl. 25 f–i)
99. Stamens 10 or fewer; leaves alternate, or sometimes appearing whorled at the ends of branches100
99. Stamens numerous; leaves oppositeHypericum (Pl. 4j, k)
100. Stamens 10; carpels 5101
100. Stamens 5; carpels 2102
101. Calyx indumentum of overlapping scales; anthers without a slender apical point (but may bear a small gland)Phebalium (Fig. 95)
101. Calyx glabrous (may be warty and/or glandular); anthers with a small whitish apical pointPhilotheca myoporoides (Fig. 96)
102. Shrubs or trees; flowers not usually pendant; fruit a rather hard-walled capsule with seeds immersed in sticky pulpPittosporum (Figs. 130–1)
102. Twining climbers; flowers usually pendant; fruit a berry (Billardiera) or thin-walled capsule (Marianthus); seeds not immersed in sticky pulpBillardiera & Marianthus (Figs. 128–9)
103. Flowers zygomorphic104
103. Flowers actinomorphic114
104. Flowers pea-shaped; stamens 10105
104. Flowers not pea-shaped; stamens 4 or 5110
105. Stamens all united or all free106
105. Stamens 9 united and one free108
106. Stamens all united; 2 upper calyx lobes broadly rounded, much larger than the other 3Platylobium obtusangulum (Fig. 69)
106. Stamens all free; calyx lobes all similar in size107
107. Stipules present; bracteoles borne on the calyxPultenaea (Figs. 67–8)
107. Stipules absent or minute; bracteoles (often readily falling) borne on the pedicelDillwynia (Fig. 63; Pl. 15j)
108. Leaves pinnate, most leaflets modified as tendrils; flowers in axillary racemesLathyrus odoratus (Figs. 64–6)
108. Leaves trifoliolate109
109. Pod much exserted beyond the old flower; stalk of central leaflet longer than those of the lateral leafletsMedicago sativa (Pl. 16g–i)
109. Pod more or less included within the floral remains; stalks of all leaflets usually more or less equalTrifolium (Pl. 16a–f)
110. Ovary deeply four-lobed; style arising in the notch between the lobes111
110. Ovary not lobed; style terminal113
111. Leaves opposite; stems usually 4-sided; fertile stamens 2 or 4112
111. Leaves alternate and/or in a basal rosette; stems not 4-sided; fertile stamens 5Echium plantagineum (Pl. 29a–c)
112. Fertile stamens 2; anther lobes separated by an elongated connectiveSalvia verbenaca (Fig. 113)
112. Fertile stamens 4; anther lobes adjacent, not separatedProstanthera rotundifolia (Fig. 112)
113. Plants herbaceous; staminode presentScrophularia (Pl. 31a–e)
113. Plants shrubby; staminode absentEremophila (Pl. 31j–m)
114. Stamens epipetalous115
114. Stamens attached to the receptacle, or to the top of a floral tube130
115. Leaves usually small, firm, often sharply pointed, (sub-)sessile, the underside usually with the main veins distinct and parallel (Pl. 28f); base of each flower often with 2 or more closely placed bracts or bracteoles116
115. Leaves not as above; flowers without such bracts or bracteoles121
116. Flowers in dense clusters on older branches; corolla lobes each with a tuft of hairs near the tipAcrotriche serrulata (Pl. 28f)
116. Flowers on current season’s branches, solitary or in short spikes or clusters; corolla lobes glabrous or uniformly hairy117
117. Corolla lobes overlapping or crumpled in bud118
117. Corolla lobes valvate in bud, not crumpled120
118. Base of flower encased in numerous overlapping bracts; fruit a capsule119
118. Base of flower subtended by a bract and 2 bracteoles; fruit a drupeBrachyloma daphnoides (Pl. 28g)
119. Corolla lobes not crumpled in bud; stamens attached in the throat of the tubeEpacris impressa (Figs. 103–4; Pl. 28h)
119. Corolla lobes contorted in bud; stamens hypogynous or the thin filaments partially attached to the tubeWoollsia pungens (Fig. 111)
120. Corolla lobes uniformly densely hairy on the inner surfaceLeucopogon (Figs. 105–6)
120. Corolla lobes glabrous or papillose internallyLissanthe (Fig. 107)
121. Fruit usually many-seeded, a capsule or berry, or with few seeds and splitting into parts; stamens 5122
121. Fruit a drupe; stamens usually 4Myoporum (Pl. 31f–i)
122. Inflorescence a scorpioid cyme (Pl. 29b, d); fruit splitting into (usually 4) one-seeded partsHeliotropium europaeum (Pl. 29d–f)
122. Inflorescences various (but not a scorpioid cyme); fruit a capsule or berry123
123. Fruit a berry125
123. Fruit a capsule124
124. Plant a bushy shrub to c. 3 m high; flowers axillaryBrugmansia hybrid (Pl. 29g–i)
124. Plant herbaceous; inflorescence loosely paniculate, terminalNicotiana suaveolens (Pl. 30j)
125. Berry enclosed by the enlarged calyxPhysalis hederifolia (Pl. 30i)
125. Berry exposed; calyx not or little enlarged in fruit126
126. Corolla rotate, mostly evenly coloured; anthers dehiscing by terminal pores or short slits127
126. Corolla tubular, evenly coloured or marked with contrasting lines; anthers dehiscing by longitudinal slits128
127. Calyx with 5 small teeth, and 5 extra small lobes on the tube, one between each pair of calyx teeth; style curvedLycianthes (Pl. 30e, f)
127. Calyx 5-lobed, without extra lobes; style straightSolanum (Pl. 30 k–n)
128. Corolla bell-shaped, marked with longitudinal dark linesDuboisia hopwoodii (Pl. 30h)
128. Corolla narrowly tubular, or urn-shaped, evenly coloured129
129. Rhizomic herbaceous perennial; flowers solitary, axillary, pendulousSalpichroa origanifolia (Pl. 30a–d)
129. Bushy shrub; flowers in terminal paniclesCestrum parqui (Pl. 30g)
130. Leaves with sheathing bases131
130. Leaves articulate on the stem132
131. Corolla upper part shed as a cap as the flower opens; filaments thickened towards the anthersRichea procera (Fig. 108)
131. Corolla persistent, the lobes spreading; filaments slenderSprengelia incarnata (Figs. 109–10)
132. Plant stems twining; flowers pendulous, one or few in leaf axils; fruit a berry (Billardiera) or thin-walled capsule (Marianthus)Billardiera & Marianthus (Figs. 128–9)
132. Plant stems erect, herbaceous; flowers in a terminal spike; fruit breaking into (usually 3) one-seeded segmentsStackhousia (Fig. 75)
132. Plants shrubs or trees; inflorescences various; fruit various133
133. Stamens 8134
133. Stamens 5 or 10135
134. Anthers united until dehiscence; fruit a capsuleErica (Pl. 28a–e)
134. Anthers free; fruit of 4 segmentsCorrea reflexa (Fig. 93)
135. Flowers showy, to c. 5 cm or more across; anthers opening by terminal poresRhododendron lochiae (Pl. 28i–k)
135. Flowers < 1.5 cm diameter; anthers opening by longitudinal slits136
136. Leaves sessile; carpels 5; placentation axileWoollsia (Fig. 111)
136. Leaves petiolate; carpels 2; placentation parietalPittosporum angustifolium (Fig. 130)
137. Petals free138
137. Petals united, or (in Pterostylis) 2 petals united with the dorsal sepal155
138. Flowers zygomorphic; perianth in 2 whorls of 3 parts, one member of the inner whorl modified as a labellum (Orchids)139
138. Flowers actinomorphic; perianth in 2 whorls of 4 or 5; no part modified144
139. Flowers apparently upside down, the labellum above the column140
139. Flowers with the labellum below the column141
140. Flowers numerous, crowded in a terminal spike Prasophyllum (Pl. 9h) 140. Flowers pedicellate, 1 to 4 at the stem apexCaleana minor (Pl. 9i)
141. Labellum longer than other perianth parts, densely hairy on the upper surfaceCalochilus robertsonii (Fig. 26)
141. Labellum shorter than other perianth parts, fringed and/or papillose, or warty or with scattered calli142
142. Floral bract completely concealing the ovary, and overlapping the base of the perianthPyrorchis nigricans (Fig. 27)
142. Floral bract not concealing the ovary143
143. Leaves 2; labellum entireChiloglottis valida (Fig. 24)
143. Leaf single; labellum margins often fringedCaladenia (Fig. 25; Pl. 9f)
144. Sepals and petals 4145
144. Sepals and petals 5146
145. Plant a shrub; fruit a berryFuchsia (Fig. 80; Pl. 19d, e)
145. Plant herbaceous; fruit a capsule or nut-likeOenothera (Pl. 19a–c)
146. Plant a herbaceous biennial; inflorescence a compound umbelDaucus carota (Pl. 34)
146. Plant a shrub or tree; inflorescences various but not a compound umbel147
147. Shrub, deciduous; branchlets often thorny; leaves stipulate, without aromatic oil glandsChaenomeles speciosa (Fig. 71)
147. Shrubs or trees, evergreen; stipules absent or tiny and falling readily; leaves with numerous aromatic oil glands148
148. Inflorescence an intercalary spike149
148. Inflorescence various but not an intercalary spike150
149. Stamens united in 5 bundlesMelaleuca (Fig. 91; Pl. 19j)
149. Stamens freeCallistemon citrinus (Figs. 81–2)
150. Fruit a berry151
150. Fruit dry, usually a capsule152
151. Leaves pale hairy below; stamens red, to c. 2.5 cm longAcca sellowiana (Pl. 19f, g)
151. Leaves glabrous, green on both surfaces; stamens pale, to c. 5 mm longSyzygium smithii (Pl. 19h, i)
152. Stamens united in 5 bundlesLophostemon confertus (Pl. 20a–d)
152. Stamens free153
153. Fruit indehiscent; ovary 1-locular; each sepal often ending in an awnCalytrix tetragona (Fig. 83)
153. Fruit dehiscent; ovary 2- or more locular; sepals not awn-tipped154
154. Stamens longer than petalsKunzea (Fig. 89; Pl. 20e–g)
154. Stamens shorter than petalsLeptospermum (Fig. 90; Pl. 20h, i)
155. Dorsal sepal and lateral petals united to various degrees to form a hood over the reproductive partsPterostylis (Figs. 28–9)
155. Sepals/calyx free from petals/corolla; flowers not hooded156
156. Style and staminal filaments united in a column (Pl. 32a), capable of moving rapidly in response to touchStylidium (Fig. 114; Pl. 32a)
156. Style free from the stamens157
157. Rhizomic, mat-forming perennial, usually of saline sitesSelliera radicans (Pl. 5g–i)
157. Upright shrubs or herbaceous perennials, not of saline sites158
158. Petal lobes all arrayed on one side of the flower (fan-like), often blue to mauveScaevola (Pl. 5d–f)
158. Petal lobes not all on one side of the flower, often yellowGoodenia ovata (Fig. 115)
159. Flowers each enclosed by 2 greenish or purplish-tinged bracts (lemma and palea)160
159. Flowers each subtended by 1 brown or greenish bract (glume)162
160. Compression dorsal, inflorescence of (usually) two terminal spikelike racemesPaspalum distichum (Pl. 13f–i)
160. Compression lateral, inflorescence otherwise161
161. Inflorescence a simple spikeLolium perenne (Figs. 39, 40; Pl. 13c)
161. Inflorescence of 2 to several spikes borne digitately at the ends of the stemsCynodon dactylon (Fig. 41; Pl. 13d, e)
161. Inflorescence a loose panicleBromus catharticus (Fig. 38; Pl. 13a, b)
162. Srems slender, more or less cylindrical; inflorescence a dense cluster of spikelets; glumes mostly brownish, spirally arranged on each spikelet axisFicinia nodosa (Pl. 12d–g)
162. Stems flattened; inflorescence a much-branched, rather dense panicle; glumes brown, spirally arranged in each spikelet; style-base persisting as a pale cap on the fruitLepidosperma (Pl. 12a–c)
162. Stems green, trigonous; inflorescence of up to c. 10 stalked, dense clusters of spikelets; glumes greenish, distichous (spikelets compressed laterally)Cyperus eragrostis (Pl. 12 h, i)
