Prasophyllum (VicFlora, 2021)

Ayre, Bronwyn M., Hayashi, Tobias, Phillips, Ryan D. & Reiter, Noushka, 2021, The Kiandra leek orchid is the previously presumed extinct mignonette leek orchid (Orchidaceae; Orchidoideae): evidence from morphological comparisons, Phytotaxa 528 (2), pp. 71-83 : 81-83

Proposed modified VicFlora Key to Prasophyllum identification.

1 Ovary attenuate, cylindric to narrow obovoid, appressed to rachis ...................................................................................................2

- Ovary obovoid to pyriform, not appressed to rachis ..........................................................................................................................4

2 Labellum bent at an angle greater than 90 deg., basal portion pouched, callus ending in two protruding knuckles ........................... ......................................................................................................................................................................... Prasophyllum australe

- Labellum bent at an angle less than 90 deg., basal portion not pouched, callus not ending in protruding knuckles.........................3

3 Leaf-blade more than 3 cm long; labellum margins voluminous, not incurved; tubers ovoid.......................... Prasophyllum elatum

- Leaf-blade less than 3 cm long; labellum margins narrow, incurved; tubers rhizomatous ............................... Prasophyllum flavum

4 Labellum lamina and/or callus papillate or pubescent .......................................................................................................................6

- Labellum lamina and callus not papillate or pubescent....................................................................................................................10

5 Labellum with a sigmoid bend when viewed from the side..................................................................... Prasophyllum lindleyanum

- Labellum bent once at about 90 deg. near the middle........................................................................................................................6

6 Ovaries tumid, roundish at anthesis............................................................................................................... Prasophyllum occultans

- Ovaries not tumid, narrow ellipsoidal at anthesis ..............................................................................................................................7

7 Perianth segments usually not widely opening, at least petals remaining forwards-directed; labellum lamina pink (sometimes fading to white with age) with a green callus.................................................................................................... Prasophyllum roseum

- Perianth segments spreading; labellum lamina whitish with a brownish callus, or labellum (and usually other segments) deep pink to purple and shining ..........................................................................................................................................................................8

8 Labellum lamina and usually other floral segments, deep pink to purplish, distinctly glossy; callus of similar colour but darker .... .......................................................................................................................................................................... Prasophyllum nitidum

- Labellum lamina pale green or whitish with a brownish callus, neither it nor other segments distinctly glossy ..............................9

9 Lateral sepals more or less parallel, narrow and not flared at the base; labellum <3 mm wide, recurved near midde then the tip recurved beyond vertical; known only from Stawell area................................................................................ Prasophyllum stygium

- Lateral sepals spreading, broad and flared widely at the base; labellum> 3 mm wide, recurved near middle and the tip remaining about vertical; known only from Edenhope area......................................................................................... Prasophyllum spadiceum

10 Labellum callus hardly raised, lamina prominently crisped and undulate toward margin, usually white, translucent....................11

- Labellum callus distinctly raised, lamina not prominently crisped, variously coloured, not translucent ........................................18

11 Lateral sepals joined for at least part of their length ........................................................................................................................12

- Lateral sepals free to base.................................................................................................................................................................13

12 Labellum reflexed back on itself; not alpine ................................................................................................ Prasophyllum brevilabre

- Labellum reflexed at about 90 deg; alpine ....................................................................................................... Prasophyllum suttonii

13 Flowering stem to 80 cm high; lowland heaths.............................................................................................. Prasophyllum spicatum

- Flowering stem usually <50 cm tall; various habitats......................................................................................................................14

14 Petals lavender; labellum pink; lateral sepals gibbous at base; Bayswater to Heathmont east of Melbourne where probably extinct ................................................................................................................................................... Prasophyllum colemaniarum

- Combination of flower features not as above; widespread and variable..........................................................................................15

15 Ovaries short, pyriform; labellum narrow, reflexed at more than right angles near middle; alps and subalps only............................ .......................................................................................................................................................................... Prasophyllum suttonii

- Ovaries somewhat elongate, obovoid; if labellum ever reflexed beyond right-angles, habitat not alpine.......................................16

16 Sepals to 10 mm long; labellum 6–10 mm long; widespread species from a range of habitats.......................................................17

- Sepals 10–12 mm long; labellum 12–15 mm long; known only from grassland in north-central Victoria and Callitris woodlands of the north-west .................................................................................................................................................... Prasophyllum beatrix

17 Lateral sepals diverging; habitat various but not from deep sands in north-western Victoria ...................... Prasophyllum odoratum

- Lateral sepals parallel or nearly so; known with certainty only from deep sand mallee-heath in north-western Victoria .................. ............................................................................................................................................................................ Prasophyllum rousei

18 Labellum callus most prominent near the labellum bend, not extending to labellum apex; perianth segments generally short and broad; lateral sepals usually free ......................................................................................................................................................19

- Labellum callus most prominent beyond the labellum bend, extending almost to labellum apex; perianth segments slender; lateral sepals often joined at least near base................................................................................................................................................28

19 Labellum with a tail-like caudiform apex .......................................................................................... Prasophyllum appendiculatum

- Labellum with an apiculate to obtuse apex ......................................................................................................................................20

20 Perianth mostly incurved; labellum callus ending in a highly raised verrucose horse-shoe shaped structure..................................... .......................................................................................................................................................................... Prasophyllum frenchii

- Perianth spreading widely; labellum callus not as above.................................................................................................................21

21 Labellum callus extending to, or just beyond, bend; labellum lamina extending well beyond end of callus ..................................22

- Labellum callus extending well beyond bend; labellum lamina not extending well beyond end of callus .....................................24

22 Petals <7.0 mm long; lateral sepals <9.0 mm long; flowers December to January ...................................... Prasophyllum uvidulum

- Petals> 7.5 mm long; lateral sepals>9.0 mm long; flowers October to November.........................................................................23

23 Callus ovate-oblong, broad and open; petals very broad, whitish, similar in colour to labellum lamina ....... Prasophyllum anticum

- Callus lanceolate, channelled; petals narrow, greenish, similar in colour to the lateral sepals ............................................................ .................................................................................................................................................. Prasophyllum sp. aff. diversiflorum 2

24 Labellum margins crisped to undulate; petals broad, similar in colour to labellum lamina.............................................................25

- Labellum margins entire to slightly irregular; petals narrow, similar in colour to the lateral sepals ...............................................26

25 Labellum laterally compressed near bend; petals whitish; moist grassland near water-courses............. Prasophyllum diversiflorum

- Labellum not laterally compressed; petals reddish; coastal heath and scrub on sand...................................... Prasophyllum litorale

26 Lateral sepals partially connate; alpine herbfields; flowers mostly January........................................... Prasophyllum niphopedium

- Lateral sepals free to base; low altitude grasslands; flowers October to December ........................................................................27

27 Lateral sepals more or less parallel; labellum lamina usually white, not constricted; grasslands south of Ballarat............................ ............................................................................................................................................................................ Prasophyllum fosteri

- Lateral sepals diverging; labellum lamina usually pink, often constricted just beyond the bend; grasslands near Warrnambool....... ......................................................................................................................................................................... Prasophyllum viretrum

28 Flowers opening widely with petals and sepals reflexed; labellum erect almost from base............................................................29

- Flowers not opening widely; labellum only erect from the bend.....................................................................................................31

29 Petals retroflexed, not upswept; lateral sepal <7 m long................................................................................ Prasophyllum morganii

- Petals recurved, upswept; lateral sepals> 6 mm long......................................................................................................................30

30 Inflorescence of up to 20 flowers in an open inflorescence; stigmatic plate much longer than column wings; grasslands near Bairnsdale..................................................................................................................................................... Prasophyllum correctum

- Inflorescence of up to 50 flowers in a crowded inflorescence; stigmatic plate of similar length to column wings; grasslands near Mortlake ........................................................................................................................................... Prasophyllum sp. aff. correctum

31 Labellum with a broad white lamina; petals with extensive white colouration at distal end; grasslands near Wangaratta ................. ................................................................................................................................................................... Prasophyllum argillaceum

- Labellum and petals not as above; widespread ................................................................................................................................32

32 Plants from higher altitude grasslands, herbfields and swampy heaths often on peaty soils ...........................................................33

- Plants from lower altitude sites, or if in montane areas then in dry woodlands on shallow soils ....................................................34

33 Sepals to 6.5 mm long; labellum sessile................................................................................................. Prasophyllum tadgellianum

- Sepals> 6.5 mm long; labellum on a short stalk...................................................................................... Prasophyllum sphacelatum

34 Plants from well-drained shallow or dry sandy soils........................................................................................................................35

- Plants from waterlogged or seasonally inundated heavy loams, silts, peats or peaty sand..............................................................45

35 Flowers <12 mm × 7 mm .................................................................................................................................................................36

- Flowers> 12 mm × 7 mm .................................................................................................................................................................39

36 Labellum callus with a deep groove down centre for entire length; apex of lateral sepals often unequally bidentate ........................ .................................................................................................................................................................. Prasophyllum subbisectum

- Labellum callus not deeply grooved for the greater part; apex of lateral sepals not or weakly bidentate .......................................37

37 Lateral sepals connate at base; coastal heathlands east of French Island.................................................. Prasophyllum parviflorum

- Lateral sepals mostly free; woodlands and heathy woodlands of western Victoria .........................................................................38

38 Plants usually> 16 cm tall; flowers>10 per inflorescence; dry inland areas ............................. Prasophyllum sp. aff. occidentale C - Plants usually <16 cm tall; flowers <10 per inflorescence; mesic near coastal areas ......................... Prasophyllum aff. parviflorum

39 Apex of lateral sepals usually strongly bidentate .............................................................................................................................40

- Apex of lateral sepals not or only weakly bidentate.........................................................................................................................41

40 Labellum margins entire or slightly irregular; lateral sepals> 8 mm long ..................................................... Prasophyllum barnettii

- Labellum margins irregularly wavy to crinkled-crenulate; lateral sepals 6–7.5 mm long......................... Prasophyllum occidentale

41 Distal margins of labellum irregularly crenulate.............................................................................. Prasophyllum sp. aff. montanum

- Distal margins of labellum entire or slightly irregular .....................................................................................................................42

42 Labellum callus wrinkled; perianth segments relatively broad, usually greenish brown; labellum lamina not pure white ............43

- Labellum callus not wrinkled; perianth segments relatively narrow, usually light greenish; labellum lamina white......................44

43 Flowers <20 mm long; labellum tapering gradually from below the middle to the apex, margins broad and often conspicuously veined; petals tapering from base to apex .................................................................................................... Prasophyllum pyriforme

- Flowers often> 20 mm long; labellum abruptly contracted near middle to a slender tail-like tip, margins not as above; petals not tapering from base to apex ........................................................................................................................... Prasophyllum maccannii

44 Flowers to 15 mm; plants of near coastal forests ........................................................................................... Prasophyllum sylvestre

- Flowers> 15 mm; plants of inland open forests and woodlands .......................................................... Prasophyllum sp. aff . validum

45 Distal labellum margins undulate to crenulate .................................................................................................................................46

- Distal labellum margins entire, more or less flat to slightly irregular..............................................................................................47

46 Flowers to 12 × 7 mm; distal labellum margins undulate to crenulate; known from Bulloke and Belah woodlands on wet loams and cracking clay; flowers September–October................................................................................................ Prasophyllum occidentale

- Distal labellum margins undulate-crispate, voluminous; flowers usually bright pink and white; found in grassy redgum woodlands on heavy clay loam soils; flowers November–December ........................................................................ Prasophyllum hygrophilum

47 Flowers to 12 × 6 mm .......................................................................................................................................................................48

- Flowers>12 × 6 mm ........................................................................................................................................................................51

48 Labellum length to width ratio>2; labellum lamina <0.3 mm wide................................................................................................49

- Labellum length to width ratio <2; labellum lamina> 0.4 mm wide................................................................................................50

49 Lateral sepals 2–3 mm long; labellum protruding forward and strongly reflexed in distal third; southern Victorian basalt plains grassland; flowers October–November ....................................................................................................... Prasophyllum suaveolens

- Lateral sepals 5–7 mm long; labellum erect and only slightly reflexed in distal third; northern Victorian grasslands on winter-wet heavy clays; flowers August–September.......................................................................................... Prasophyllum aff. occidentale D

50 Labellum reflexed at <90 deg. in distal half; lateral sepals not bidentate at apex; plants not clumping; River Red Gum woodlands on water-retentive clay; flowers October to November ..................................................................... Prasophyllum erythrocommum

- Labellum reflexed at>90 deg. in distal half; lateral sepals often bidentate at apex; plants often clumping; southern Victorian basalt plains grassland; flowers September to October ......................................................................... Prasophyllum sp. aff. occidentale E

51 Lateral sepals contracting abruptly; River Red Gum woodlands on water-retentive clay; northeast Victoria; flowers October– November ............................................................................................................................................................ Prasophyllum gilgai

- Lateral sepals tapering evenly from base to apex; habitat not as above...........................................................................................52

52 Lateral sepals with acute to shortly acuminate, widely diverging apices; flowers to 9 mm across; petals to 8.5 mm long; swampy habitats; western Victoria; flowers December to January ................................................................................... Prasophyllum readii

- Lateral sepals with long-acuminate, not widely diverging apices; flowers 9 mm across or more; petals 9 mm long or more; dryer habitats; eastern Victoria; flowers October to November .................................................................... Prasophyllum chasmogamum