Cyathea, Smith, 1793

Lehnert, Marcus, 2012, A synopsis of the species of Cyathea (Cyatheaceae-Polypodiopsida) with pinnate to pinnate-pinnatifid fronds, Phytotaxa 61 (1), pp. 17-36 : 19-22

Key to the Neotropical species of Cyathea with pinnate to pinnate-pinnatifid fronds

For a key to the genera of Neotropical Cyatheaceae see Lehnert (2011b); for a key to the groups of the genus Cyathea sensu strictu see Lehnert (2011a).

1 Rhachises densely covered with spreading, basally attached scales 5–8(–10) × 0.5–1.0 mm; pinnae 25–50 pairs per frond, veins all free [exindusiate] .......................................................................................................... Cyathea ursina

– Rhachises not covered with spreading scales or scales few and appressed; pinnae mostly less than 25 pairs per frond, if rarely up to 35 pairs then veins forming areoles ....................................................................................................... 2

2 Fronds spirally arranged along a thin climbing rhizome (1.5–2.0 cm diameter), scales weakly discordantly bicolorous, yellowish white to stramineous with brown central stripes; laminae abruptly reduced to a pinna-like section ..... ........................................................................................................................................................ Cyathea assurgens

– Fronds clustered at rhizome/trunk apices, scales often darker, concolorous or bicolorous with white margins; if scales pale and trunk thin then laminae gradually reduced........................................................................................... 3

3 Rhachises notably green-alate throughout or in most parts.......................................................................................... 4

– Rhachises not green-alate or only weakly so in distal parts ....................................................................................... 12

4 Pinnae less than 10 cm long and to 2.2 cm (mostly less than 2 cm) broad; rhachises glabrous or hairy with hairs to 1.2 mm long; exindusiate .............................................................................................................................................. 5

– Pinnae 10–33 cm long and to 3.6 cm broad (sometimes only 1.6 cm broad); rhachises glabrous on both sides, or sparsely hairy with hyaline hairs to 0.5 mm long, indusiate........................................................................................ 6

5 Rhachises completely glabrous; pinnae 9–12(–20) pairs per frond, to 6.5 × 2.2 cm ........................... Cyathea nanna

– Rhachises densely hairy on both sides, hairs adaxially 0.5–1.0 mm long, brown to tan, antrorsely curved, abaxially 1.0– 1.2 mm long, white; pinnae 14–25 pairs per frond, to 7.5 × 1.4–1.8 cm ............................ Cyathea pseudonanna

6 All veins free, rarely forming costal areoles................................................................................................................. 7

– Veins regularly merging to form costal , sometimes also lateral areoles....................................................................... 9

7 Pinnae 16–22(–26) pairs per frond [pinnae incised to 3/4 towards the costae, medial ones opposite to subopposite, distal and proximal ones alternate; pinna bases equilateral, truncate].............................................. Cyathea chiricana

– Pinnae 5–12(–20) pairs per frond ................................................................................................................................. 8

8 Pinnae 5–6 pairs per frond, alternate; sori 0.8 mm diameter, medial, parallel to the midrib; indusia hemitelioid, reaching to 1/4 around the receptacles.................................................................................................. Cyathea minuta

– Pinnae 9–12 pairs per frond, mostly opposite; sori 1.2–1.5 mm diam., in a triangular pattern medial to the midveins; indusia reaching 1/2 to 2/3 or more around the receptacles......................................................... Cyathea glandulifera

9 Pinnae 14–26 pairs per frond [pinnae incised to 1/4 towards the costae, pinna bases inequilateral with the basiscopical side pronounced as small auricle] ......................................................................................................................... 10

– Pinnae 5–12(–20) pairs per frond .............................................................................................................................. 11

10 Petioles not green-alate; pinnae to 16 × 1.6–2.6 cm, strictly opposite; laminae gradually reduced.... Cyathea varians

– Petioles usually green-alate throughout; pinnae to 33.0 × 3.0– 3.6 cm, alternate to opposite; laminae gradually reduced to abruptly reduced to conform apical sections.......................................................... Cyathea decurrentiloba

11 Petiole scales concordantly to discordantly bicolorous, dark brown to castaneous with white margins, in distal petiole parts concolorous white or with a discontinuous brown central streak [indusia reaching 1/2 around the receptacles, rarely more, midveins with 1 cm or more between them] ....................................................... Cyathea alatissima

– Petiole scales almost concolorous dark brown to castaneous with paler margins [indusia reaching 2/3 to 3/4 around the receptacles, rarely discoid, midveins strongly protruding, usually 1 cm or less between them] .............................. ....................................................................................................................................................... Cyathea choricarpa

12 Pinnae entire or incised less than 1/3 (mostly 1/5) towards the costa ........................................................................ 13

– Pinnae pinnatifid to pinnatisect, incised at least 1/3 towards the costa, the largest pinnae sometimes basally fully pinnate......................................................................................................................................................................... 27

13 Laminar apices gradually reduced, not pinna-like (somewhat transient if lateral pinnae small and entire), pinnae shorter than 10 cm [veins free, only occasionally with single areoles] ...................................................................... 14

– Laminar apices abruptly reduced, pinna-like or with basal lobes; largest pinnae more than 10 cm long. [Veins free or forming areoles] .......................................................................................................................................................... 16

14 Pinna bases truncate to cordate, apices ± acute; petiole scales concolorous castaneous or with indistinct paler margins........................................................................................................................................................ Cyathea falcata

– Pinna bases round to cuneate, apices obtuse to round; petiole scales almost concolorous white to stramineous ...... 15

15 Sori with small appresssed hemitelioid indusia................................................................................. Cyathea haughtii

– Sori exindusiate...................................................................................................................................... Cyathea brucei

16 Vein anastomosing, regularly forming areoles ........................................................................................................... 17

– Veins free, only occasionally with single areoles, anastomosing veins thinner than free veins ................................. 22

17 Largest pinnae elliptic, 25–45 × 6–8 cm, ± entire with subentire to serrulate margins; indusia cyatheoid or hemitelioid and reaching 3/4 or more around the receptacles ............................................................................................... 18

– Largest pinnae 2.2–6.5 cm broad, linear to long triangular and incised to 1/3 towards the costae, if pinnae elliptic to oblanceolate then only to 25 cm long ......................................................................................................................... 19

18 Indusia hemitelioid; midveins less than 1 cm apart; largest pinnae 6–7 cm wide, with truncate bases, margins serrulate at least at tips.......................................................................................................................... Cyathea karsteniana

– Indusia cyatheoid; midveins more than 1 cm apart; largest pinnae (6.5–)7.5–8.0 cm wide, with cuneate bases, margins crenate at least at tips.................................................................................................................... Cyathea nervosa

19 Indusia discoid; rhachises abaxially hairy ........................................................................................ Cyathea stolzeana

– Indusia hemitelioid, reaching to 1/2 around the receptacles; rhachises glabrous abaxially ...................................... 20

20 Pinnae 15–24 pairs per frond, 2.2–4.5 cm wide, incised commonly 1/3–1/5 towards the costae (in distal parts and in small plants almost entire); indusia hemitelioid, reaching 1/4 to 1/3 around the receptacles; basal veins always arising from the midvein ................................................................................................................... Cyathea subincisa

– Pinnae 8–12 pairs per frond, 3.0– 6.5 cm wide, margins subentire to incised less than 1/5 towards the costae; indusia reaching 1/2 or more around the receptacles; basal veins sometimes arising from the costae................................... 21

21 Basal veins arising from the midveins; indusia reaching 1/2 to 2/3 around the receptacles; largest pinnae 20.0–25.0 × 3.0– 6.5 cm, linear-elliptic to oblanceolate............................................................................................. Cyathea ewanii

– Basal veins arising from the costae or from the axils between costae and midribs; indusia reaching about 1/2 around the receptacles; largest pinnae 29.0–34.0 × 3.4–4.9 cm broad, lanceolate to long triangular ...... Cyathea roraimensis

22 Sori marginal [with large hemitelioid indusia] ................................................................................... Cyathea speciosa

– Sori in zigzag pattern or in several lines parallel to the costae [mainly exindusiate, rarely hemitelioid indusia]...... 23

23 Pinnae 4–9 pairs per frond, petiole scales 5.0–7.0 × 1.5–2.0 mm ......................................................... Cyathea stolzei

– Pinnae 10–16 pairs per frond; petiole scales to 15.0 × 5.0 mm.................................................................................. 24

24 Indusia hemitelioid, reaching 1/2 to 2/3 or more around the recpetacles; veins glabrous except for abundant reddish brown trichomidia abaxially, evenly distributed on and between them....................................... Cyathea glandulifera

– Indusia absent or developed as ephemeral mucose layer; veins glabrous or with ephemeral white to tan unicellular trichomidia on and between them, adaxially glabrous or with few scattered, tortuous, hyaline multicellular hairs to 2 mm long ...................................................................................................................................................................... 25

25 Pinnae basally cuneate to round, apically obtuse to round, margins entire ..................................... Cyathea cyclodium

– Pinnae basally cuneate, apically acuminate to attenuate, margins crenulate to dentate ............................................. 26

26 Plants with trunk to 1(–4) m tall; pinnae opposite, strongly dimorphic (fertile ones to 2.5 cm wide, sterile ones 4.0– 4.5 cm wide).............................................................................................................................. Cyathea williamsii

– Plants without trunk; pinnae mostly alternate, weakly dimorphic (fertile ones weakly narrower than sterile ones, 2.0– 2.5 cm wide)................................................................................................................................ Cyathea maguirei

27 (12) Pinnae notably stalked, apparently glabrous (few scattered hairs may occur), sori proximal to subproximal ... 28 – Pinnae mostly sessile to subsessile, glabrous to densely hairy, if stalked to 20 mm then fronds almost glabrous and sori marginal and indusiate ......................................................................................................................................... 30

28 Petiole scales concolorous auburn to deep brown; laminar indument with almost circular, pseudopeltately attached squamules; segments subentire to entire with round tips, basal segments never free [sori exindusiate]........................ ........................................................................................................................................................ Cyathea latevagans

– Petiole scales concolorous white to stramineous or bicolorous with dark brown central streak; laminar indument without circular, pseudopeltately attached squamules; segments crenulate with round to acute tips, basal segments often free ..................................................................................................................................................................... 29

29 Petiole scales to 12 × 1.5 mm; veins abaxially only with flat squamules; sori with hemitelioid indusia ...................... ................................................................................................................................................... Cyathea windischiana

– Petiole scales 15–25 × 2.5–4.0 mm; veins abaxially with bullate squamules; sori exindusiate............ Cyathea werffii

30 Largest pinnae 2(–2.5) cm wide; pluricellular hairs ± 1 mm long at least present adaxially on rhachises and costae, often whole plant abundantly hairy with hairs to 5 mm long; petiole scales of all colors, sometimes very narrow and hair-like ( Cyathea bipinnatifida and look-alikes) ....................................................................................................... 31

– Largest pinnae more than 2 cm wide (mostly 3–8 cm); hairs absent or only 0.5–0.6 mm long, whole plant apparently glabrous; petiole scales white to bicolorous dark brown to blackish with white margins, always broad-lanceolate to ovate, never hair-like................................................................................................................................................... 44

31 Laminar indument with hairs 3–5 mm long, especially along rhachises.................................................................... 32

– Laminar indument consisting of short pubescence, hairs rarely longer than 1 mm ................................................... 34

32 Scales on trunks and basal petioles broadly lanceolate to ovate, never transient with hairs, in most petiole parts concolorous stramineous to whitish, at petiole bases and on trunks strongly bicolorous dark castaneous to blackish with stramineous to whitish margins; rhachises strongly hairy [indusia hemitelioid]............................... Cyathea decorata

– Scales on trunks and basal petioles narrowly triangular with long marginal cilia, intergrading with hairs in distal petiole parts, stramineous to rufescent [indusia absent] .................................................................................................. 33

33 Hairs absent between veins abaxially. ( Colombia, Venezuela, Colombia, N Peru) .......................... Cyathea aterrima

– Hairs also present between veins abaxially. (SE Brazil) ............................................................. Cyathea myriotricha

34 Veins forming areoles between midveins; indusia hemitelioid ............................................................. Cyathea bradei

– Veins not forming areoles between midveins; indusia cyatheoid to sphaeropteroid or absent................................... 35

35 Pinnae sometimes basally pinnate (may vary within one plant), sinuses between segments wide and predominantly acute; trunks/rhizomes without adventitious buds [indusia absent]...................................................... Cyathea werffii

– Pinnae basally not pinnate, sinuses between segments narrow or rounded; trunks/rhizomes regularly with adventitious buds, at least in posterior parts [indusia absent, cyatheoid or sphaeropteroid].................................................. 36

36 Scales on petioles pale, white to stramineous, concolorous throughout or transient with strongly bicolorous, whitemargined scales on the trunk; laminae dark green, matte to lustrous [indusia absent, hemitelioid or cyatheoid]...... 37

– Scales concolorous orange to dark brown, or strongly bicolorous with margins not white; laminae adaxially either pale green or not lustrous [indusia absent or sphaeropteroid] .................................................................................... 40

37 Scales on trunks and basal petioles strongly bicolorous, dark castaneous to blackish with stramineous to whitish margins, in most petiole parts concolorous stramineous to whitish; costae adaxially densely hairy with tan to brown multicellular hairs to 1.0 mm long; indusia absent .................................................................... Cyathea phalaenolepis

– Scales on trunks and basal petioles like in most petiole parts concolorous stramineous to whitish or rarely pale brown; either costae glabrous or hemitelioid indusia present..................................................................................... 38

38 Sori submarginal, indusia lacking, laminae coriaceous. (Guayana Highlands).................................. Cyathea demissa

– Sori medial to subproximal, indusia cyatheoid, laminae firm-herbaceous. (N Andes) .............................................. 39

39 Laminae adaxially glabrous except for few hairs on costae, indusial margins short-dentate.............. Cyathea alstonii

– Laminae adaxially short-pubescent on and between veins, indusial margins ciliate...................... Cyathea peladensis

40 Laminar hairs also present between veins; pinna pairs 22–36 per frond [indusia absent] ......................................... 41

– Laminar hairs absent between veins (may be present on veins); pinna pairs 10–18(–24) per frond [indusia absent or sphaeropteroid]............................................................................................................................................................ 42

41 Petiole scales concolorous or if bicolorous then with only weakly darker center, restricted to petiole bases; petioles glabrous or glabescent with short hairs; plants with erect trunks ............................................... Cyathea bipinnatifida

– Most petiole scales with dark brown to blackish center, persistent and extending to rhachises; petioles persistently long hairy; plants without trunks or trunks short and decumbent............................................ Cyathea phegopteroides

42 Petioles scurfy, only distally hairy near transistion to rhachis, veins lacking hairs on both sides, or with inconspciuous unicellular trichomidia instead [indusia absent].................................................................. Cyathea thelypteroides

– Petioles hairy, not scurfy, veins hairy on both sides ................................................................................................... 43

43 Largest pinnae 2.5–13.0 × 1.0– 2.5 cm, paraphyses relatively long (0.4–0.5 mm) [indusia absent] .............................. .......................................................................................................................................................... Cyathea palaciosii

– Largest pinnae to 3.2 × 1.2 cm, paraphyses relatively short (0.2–0.3 mm) [indusia sphaeropteroid]............................ ......................................................................................................................................................... Cyathea concordia 44 (30) Veins free, only occasionally with costular areoles ............................................................................................ 45

– Vein anastomosing, regularly forming areoles ........................................................................................................... 51

45 Free pinnae 6 pairs or less, pinnatifid apical section comprising ± half of the lamina.................... Cyathea singularis

– Free pinnae in 10–20 pairs, apical section comprising a small fraction of the lamina ............................................... 46

46 Lobes (= segments) acute to attenuate, sinuses acute to round .................................................................................. 47

– Lobes (= segments) obtuse to round or truncate, sinuses acute.................................................................................. 49

47 Petiole scales concolorous white or with a narrow brown central stripe....................................... Cyathea cnemidaria

– Petiole scales bicolorous dark brown to black with white margins, the latter often abraded ..................................... 48

48 Sori 1.2(–1.5) mm diameter, medial to supramedial, in a weakly to strongly undulate line parallel to the margins; largest pinnae to 50.0(–75.0) × 5.0–13.0 cm; indusia reaching 1/2 around the receptacles ................. Cyathea mutica

– Sori 0.6–0.8 mm diameter, submarginal, parallel to the margins; pinnae to 33.0 × 3.0–5.0 cm; indusia reaching about 1/3 around the receptacles.................................................................................................................... Cyathea aristata

49 Pinnae stalked to 2 cm; sori marginal to submarginal [apices gradually reduced, only known from cultivation]......... ................................................................................................................................................................ Cyathea bella

– Pinnae sessile; sori ± medial, forming delta-pattern................................................................................................... 50

50 Basal veins arising from costae or from the axils with the midveins, usually more than 1 cm between midveins (range 0.9–1.4 cm); laminar apices gradually to abruptly reduced....................................................... Cyathea uleana

–. Basal veins arising from midveins; less than 1 cm between midveins; laminar apices gradually reduced.................... .......................................................................................................................................................... Cyathea chiricana

51 Basal veins arising from the costae or from the axils between costae and midveins; apices abruptly reduced ......... 52

– Basal veins arising from the midveins (rarely few also from the axils) ..................................................................... 53

52 Sori submarginal, parallel to the margins, or distally closer to the midveins than to the margins ................................. ...................................................................................................................................................... Cyathea roraimensis

– Sori proximally/below sinuses close to costae, distally medial to inframedial, parallel to the midveins, on the back of veins ............................................................................................................................................... Cyathea chocoensis

53 Lobes (= segments) acute to attenuate, sinuses acute to round; laminar apices gradually reduced ........................... 54

– Lobes (= segments) obtuse to round or truncate, sinuses acute; laminar apices gradually to abruptly reduced ........ 56

54 Pinnae incised 3/4 or more towards the costa, to 75.0 × 7.5–18.0(–21.0) cm, 15–20 pairs per frond ........................... ............................................................................................................................................................. Cyathea horrida

– Pinnae incised ± 1/2 towards the costa, to 50 × 6 cm, 20–35 pairs per frond ............................................................ 55

55 Pinnae ca. 20–30 pairs per frond, 23.0–39.0 × 3.7–6.0 cm, distal and proximal ones alternate, medial ones subopposite to opposite ................................................................................................................................ Cyathea spectabilis

– Pinnae 30–35 pairs per frond, to 40–50 × 4.5 cm, strictly opposite ................................................... Cyathea cruciata

56 Petiole scales concolorous to discordantly bicolorous, mainly white with dark brown to castaneous central streaks... ................................................................................................................................................................................... 57

– Petiole scales bicolorous, shiny dark brown to castaneous with often abraded, wide white margins ........................ 58

57 Pinnae 12–14 pairs per frond, 35.0–40.0 × 5.0–6.0 cm, opposite; veins forming costular and lateral areoles, more than 1 cm between the midveins (1.2–1.5 cm); laminar apices abruptly reduced ........................... Cyathea consimilis

– Pinnae 16–22 pairs per frond, 16.0–23.0 × 3.5–4.5 cm, distal and proximal ones alternate, medial ones subopposite to opposite; veins forming costular areoles only, less than 1 cm between the midveins (0.6–0.8 cm); laminar apices gradually reduced............................................................................................................................... Cyathea amabilis

58 Indusia discoid, reaching all around the receptacles.......................................................................... Cyathea cocleana

– Indusia reaching 1/2 or less around the receptacles.................................................................................................... 59

59 Veins adaxially with white uniseriate hairs to 1.0 mm long, abaxially with appressed trichomidia and weak brown scurf containing small flat, tan to brown squamules to 0.5 mm long; laminar apices gradually reduced to pinnatifid apical sections ............................................................................................................................... Cyathea suprapilosa

– Veins glabrous on both sides, or abaxially with weak whitish scurf; laminar apices abruptly reduced to subconform, rarely conform (pinna-like) apical sections ................................................................................................................ 60

60 Pinnae incised 3/4 or more towards the costae .............................................................................. Cyathea grandifolia

– Pinnae incised 1/2 or less towards the costae ............................................................................................................. 61

61 Largest pinnae 25–50 × 4.5–6.5 cm, 24–30 pairs per frond; veins forming lateral areoles, fusing below sinuses to cartilaginous areas; indusia reaching ± 1/2 around recetacles ........................................................... Cyathea andicola

– Largest pinnae 20–35 × 2.2–4.5 cm, 15–24 pairs per frond; veins rarely forming lateral areoles, connivent to sinuses but not fusing to cartilaginous areas; indusia reaching 1/3 to 1/4 around recpetacles...................... Cyathea subincisa