Begonia

Moonlight, Peter. W., Jara-Muñoz, Orlando A., Purvis, David A., Delves, Jay, Allen, Josh P. & Reynel, Carlos, 2023, The genus Begonia (Begoniaceae) in Peru, European Journal of Taxonomy 881, pp. 1-334 : 24-31

Genus Begonia L.

Description

Caulescent or acaulescent herbs, with or without a tuber or rhizome. Stems erect, trailing, or climbing, sometimes rooting at the nodes. Stipules paired, either side of the petiole, persistent to deciduous. Leaves alternate, basifixed or peltate; blade simple or rarely palmately-compound, subsymmetric to asymmetric, margin entire to serrate, lobed or lacking lobes, veins peltate, palmate, palmate-pinnate, or pinnate. Inflorescences bisexual or rarely unisexual, axillary or terminal, cymose, monochasial, or thyrsoid, protandrous. Staminate flowers: tepals 2–11; stamens 2–125, filaments free or fused into a column, anthers dehiscing via lateral slits or pores, connectives extended or not extended, symmetrically basifixed or filaments symmetrically fixed to the back of the anthers. Pistillate flowers: bracteoles lacking to 3, positioned directly beneath the ovary or on the pedicel; tepals 2–11, deciduous or persistent in fruit; ovary inferior, body unequally 2- to 4-winged, lacking wings, or 3-horned, dehiscing laterally or dorsally, placentation axillary, placentae branches entire or divided; styles 2–4, free or fused, once- to many times-divided, stigmatic papillae in one or several spirally-twisted bands per style. Fruit a capsule, wings or horns same shape and size as in ovary or expanding.

Artificial key to Peruvian Begonia

1. Leaf lamina peltate .......................................................................................................................... 2

– Leaf lamina basifixed....................................................................................................................... 9

2 Plants tuberous or rhizomatous, terrestrial herbs; internodes short or lacking, if present not rooting at the nodes ...................................................................................................................................... 3

– Plants lacking a tuber or rhizome, climbing herbs; stem with elongate internodes and rooting at the nodes ................................................................................................................................................ 8

3 Plants rhizomatous........................................................................................................................... 4

– Plants tuberous................................................................................................................................. 7

4 Leaf laminae moderately to densely pubescent ............................................................................... 5

– Leaf laminae glabrous...................................................................................................................... 6

5 Leaf laminae with 1 or more large triangular lobes, margins entire; tepals deciduous in fruit ......... ....................................................................................................................... B. acerifolia Kunth 49

– Leaf laminae lacking lobes, margins serrulate; tepals persistent in fruit...... B. parcifolia A.DC. 46 6 Plant lacking an aerial stem; tepals deciduous in fruit ......................... B. urubambensis Tebbitt 76

– Plant with an aerial stem; tepals persistent in fruit ........................................ B. serotina A.DC. 54

7 Plant with an aerial stem; leaf margin serrate to dentate, rarely crenate; ovary and fruit wing apices acute...................................................................................... B. neoharlingii L.B.Sm. & Wassh. 33

– Plant lacking an aerial stem; leaf margin crenate; ovary and fruit wing apices rounded to truncate .................................................................................................................... B. joshii Moonlight 32

8 Petiole insertion <¼ of the way up the lamina; tepals red................................................................ ........................................................................................... B. aeranthos L.B.Sm. & B.G.Schub. 41

– Petiole insertion> ¼ of the way up the lamina; tepals white to yellow or green.............................. .................................................................................................................. B. hitchcockii Irmsch. 42

9 Plants with a tuber or rhizome....................................................................................................... 10

– Plants lacking a tuber or rhizome .................................................................................................. 32

10 Plants with an above ground stem ..................................................................................................11

– Plants lacking an above ground stem............................................................................................. 21

11 Plant> 50 cm tall; internodes> 5 cm long.................................................................................... 12

– Plant <50 cm tall; internodes <5 cm long.................................................................................... 13

12 Leaf margins lacking cusps; staminate flowers 12–16 mm across; tepals of the staminate flowers with rounded apices; pistillate flowers ebracteolate ........... B. piurensis L.B.Sm. & B.G.Schub. 47

– Leaf margins with 2–5 cusps along the largest side; staminate flowers 44–90 mm across; tepals of the staminate flowers with acuminate apices; pistillate flowers bracteolate...................................... .................................................................................................. B. velata L.B.Sm. & B.G.Schub. 48

13 Tuber <5 mm in diameter; leaf blades <3 × 3 cm in diameter; stamens 2 or 4 ............................... ................................................................................................. B. elachista Moonlight & Tebbitt 62

– Tuber> 1 cm in diameter; leaf blades> 3 × 3 cm in diameter; stamens> 5................................. 14

14> 50 stamens; leaf apices rounded to indistinct................................................ B. veitchii Hook.f. 5

– <40 stamens; leaf apices acute to acuminate, rarely rounded to indistinct................................... 15

15 Stems glabrous to sparsely tomentose, the hairs <1 mm long...................................................... 16

– Stems sparsely to densely villous or hispid, the hairs> 2 mm long.............................................. 19

16 Leaf venation palmate-pinnate; stems thin, wiry........................................................................... 17

– Leaf venation palmate; stems succulent ........................................................................................ 18

17 Stipule margins entire, aciliate; leaf upper and lower surfaces glabrous; stamens held on a 0.5 mm long column .......................................................................... B. speculum Moonlight & Tebbitt 74

– Stipule margins lacerate, ciliate; leaf upper and lower surfaces sparsely to densely pilose; stamens held on a 2–2.75 mm long column ............................................................ B. thyrsoidea Irmsch. 75

18 Stipules persistent; leaf margin serrate; pistillate tepals 8–10 mm long ... B. geraniifolia Hook. 31

– Stipules deciduous; leaf margin crenate to dentate; pistillate tepals 10–30 mm long ....................... .............................................................................................. B. neoharlingii L.B.Sm. & Wassh. 33

19 Tepals yellow, orange, or red; tepals glabrous on both surfaces.................................................... 20

– Tepals white to pink; tepals glandular pilose on the outer surface, glabrous on the inner surface.... ............................................................................................ B. bifurcata L.B.Sm. & B.G.Schub. 71

20 Tepals yellow; stipules persistent, 1–3.5 mm long......................................... B. heliantha Tebbitt 3

– Tepals orange to red; stipules late deciduous, 5–7 mm long. B. herrerae L.B.Sm. & B.G.Schub. 4

21 Staminate flowers with four tepals ................................................................................................ 22

– Staminate flowers with five or more tepals.................................................................................... 28

22 Leaf margins unlobed or rarely with <5 triangular lobes ............................................................. 23

– Leaf margins with> 5 irregularly-shaped lobes..................................... B. weberbaueri Irmsch. 34

23 Plants with an above-ground creeping rhizome; petioles densely hispid, the hairs red .................... ........................................................................................... B. erythrothrix Tebbitt & Moonlight 72

– Plants with an underground tuber or rhizome; petiole glabrous to densely villous, the hairs white. ....................................................................................................................................................... 24

24 Outer tepals of the staminate flowers serrate; styles multifid................. B. tumbezensis Irmsch. 40

– Outer tepals of the staminate flower entire; styles bifid ................................................................ 25

25 Ovaries sub-equally 3-winged; pistillate tepals persistent in fruit................ B. parcifolia C.DC. 46

– Ovaries unequally 3-winged; pistillate tepals deciduous in fruit................................................... 26

26 Stipules> 8.5 mm long; stamens> 50; outer tepals of the staminate flowers> 12 mm long........... .......................................................................................................................... B. veitchii Hook.f. 5

– Stipules <8.5 mm long; stamens <30; outer tepals of the staminate flower <12 mm long......... 27

27 Leaf blade sub-symmetrical, orbicular; upper leaf surface concolourous mid-green; stamens ca 25; tepals deciduous in fruit................................................................................. B. joshii Moonlight 32

– Leaf blade asymmetrical, transversely ovate; upper leaf surface dark green, flushed light green and flecked silver around the veins; stamens 11–16; tepals persistent in fruit......................................... ................................................................................ B. occultata J.P.Allen & Moonlight sp. nov. 73

28 Tepals vivid red; tepal apices acute ............................................................. B. polypetala A.DC. 38

– Tepals white to pink; tepal apices obtuse, rounded, truncate, or emarginate ............................... 29

29 Tepals apices emarginate; leaf lower surface villous to densely villous ........................................... .............................................................................................................. B. anemoniflora Irmsch. 35

– Tepals apices variously obtuse, rounded, or truncate, never emarginate; leaf lower surface glabrous to variously pubescent, rarely villous on the veins ....................................................................... 30

30 Stamens 15–50............................................................................................ B. pleiopetala A.DC. 37

– Stamens 50–100............................................................................................................................. 31

31 Pistillate tepals 6–10; leaf lower surface glabrous to sparsely lanate; leaf laminae to 25 × 27 cm ... ..................................................................................................................... B. octopetala L’Hér. 36

– Pistillate tepals 5; leaf lower surface glabrous, pubescent on the veins; leaf laminae to 15 × 11 cm ........................................................................................................ B. pseudopleiopetala Tebbitt 39

32 Leaf laminae conspicuously lobed to> ⅓ of their width or palmately compound ....................... 33

– Leaf laminae lacking lobes or lobed to <⅓ of their width............................................................ 39 33 Plant semi-scandent to scandent, lacking a rhizome or a swollen stem base; tepals bright red; stamens united into a column ................................................. B. monadelpha (Klotzsch) A.DC. 53

– Plant erect, often with a rhizome or swollen stem base; tepals white to pink; stamens free......... 34

34 Plant> 3 m tall; leaves reaching> 40 cm wide; inflorescence branching> 10 times,> 50 cm wide ........................................................................................................ B. parviflora Poepp. & Endl. 64

– Plant <2 m tall; leaves <30 cm wide; inflorescence branching <10 times, <50 cm wide.......... 35

35 Leaf lamina circular in outline; petiole apex with a ring of trichomes.......................................... 36

– Leaf lamina ovate in outline; petiole apex lacking a ring of trichomes......................................... 37

36 Stem with conspicuous petiole scars; leaf lobes sinuate, narrowly-triangular.................................. ....................................................................................................................... B. ludwigii Irmsch. 52

– Stem lacking petiole scars; leaf lobes straight, broadly-triangular.................................................... ......................................................................................... B. huancabambae Moonlight sp. nov. 51

37 Leaf lobed up to one-third of the length of the lamina; leaf margins crenate; staminate flower with <40 stamens ................................................................................................. B. arrogans Irmsch. 50

– Leaf lobed around half the length of the lamina; leaf margins serrulate to serrate; staminate flowers with> 40 stamens .......................................................................................................................... 38

38 Ovary and fruit with one long wing and two rib-like wings.......................... B. acerifolia Kunth 49

– Ovary and fruit with 3 subequal wings............................................................ B. wollnyi Herzog 55

39 Plants climbing, rooting at the nodes............................................................................................. 40

– Plants erect or with a strong prostrate stem but not climbing, rooting only at the lower nodes.... 41

40 Leaf blades more than twice as long as broad, lanceolate; stipules deciduous; inflorescences terminal, with <10 flowers; tepals bright orange or red (rarely white outside of Peru); pistillate flowers and fruits with two paired, heart shaped bracteoles obscuring the ovary ............................. ................................................................................................................. B. rossmanniae A.DC. 65

– Leaf blades less than twice as long as broad; stipules persistent; inflorescences axillary, with> 25 flowers; tepals white; pistillate flowers lacking bracteoles.................................. B. glabra Aubl. 70

41 Leaves clustered towards the apex of the stem.............................................................................. 42

– Leaves evenly spaced along the stem ............................................................................................ 47

42 Upper leaf lamina smooth, glabrous to sparsely pilose, not glandular; inflorescence apical, cymose ........................................................................................................................................... 43

– Upper leaf lamina bullate, densely glandular-pilose; inflorescence terminal, thyrsoid..................... ................................................................................................................. B. buddleiifolia A.DC. 63

43 Veins pinnate, sometimes 3 veined from the lase ( Fig. 2A–B ) ..................................................... 44

– Veins palmate-pinnate, always> 3 veined from the base ( Fig. 2C–E ).......................................... 45

44 Stipules without an apical hair; inflorescences and both leaf surfaces glabrous ............................... ..................................................................................................................... B. maynensis A.DC. 58

– Stipules terminating in a 2–4 mm long apical hair; inflorescences and both leaf surfaces sparsely pilose to pilose ................................................................... B. brandbygeana L.B.Sm. & Wassh. 45

45 Leaf lamina 10–12.5 cm long; inflorescence bracts serrate; bracteoles ovate with serrate margins; tepals yellow .................................................................... B. scorpiocaulis Moonlight & Tebbitt 59

– Leaf lamina (12–) 15–30 cm long; inflorescence bracts entire; bracteoles lanceolate with entire margins; tepals white to pink......................................................................................................... 46

46 Petioles 8–22 cm long; staminate flowers with ca 40 stamens; upper edge of largest fruit wing ascending ................................................................................................ B. albomaculata C.DC. 56

– Petioles 3.5–10 cm long; staminate flowers with ca 20 stamens; upper edge of largest fruit wing perpendicular to the ovary ............................................................. B. chemillenensis Moonlight 57

47 Leaf veins pinnate.......................................................................................................................... 48

– Leaf veins palmate or palmate pinnate .......................................................................................... 58

48 Stipules large and persistent, longer than the internodes... B. imbrexiformis Moonlight sp. nov. 12

– Stipules deciduous or persistent, never longer than the internodes ............................................... 49

49 Fruits 3-horned with an elongated apical column; tepals white, pink, orange, or red................... 50

– Fruits with three wings, lacking an apical column; tepals white or pink ...................................... 52

50 Stipules late deciduous; tepals of the pistillate flower <6 mm long; outer two tepals of the staminate flower <8 mm long ................................................................................................. B. urticae L.f. 8

– Stipules deciduous; tepals of the pistillate flower> 8 mm long; outer two tepals of the staminate flower> 8 mm long ....................................................................................................................... 51

51 Tepals red; stamens 4–6; outer tepals of the staminate flower <15 mm long................................... ..................................................................................... B. condorensis Jara & Moonlight sp. nov. 6

– Tepals orange; stamens 12–18; outer tepals of the staminate flower> 20 mm long......................... .................................................................................... B. hirta (Klotzsch) L.B.Sm. & B.G.Schub. 7

52 Plant an annual, 30 cm tall or less ............................................................... B. semiovata Liebm. 28

– Plant a perennial, at least 30 cm tall .............................................................................................. 53

53 Secondary leaf veins indistinct; staminate flower with 4 tepals .................................................... 54

– Secondary leaf veins prominent; staminate flower 2 tepals........................................................... 55

54 Leaf laminae to 3.5 × 1.2 cm, with 1–4 secondary veins on both sides of the laminae; stamens 30–50; styles bifid.............................................................................................. B. foliosa Kunth 60

– Leaf laminae to 10 × 4.5 cm, with 5–7 secondary veins on both sides of the laminae; stamens 15–25; styles multifid ................................................................................. B. guaduensis Kunth 61

55 Stems densely tomentose................................................................................ B. ulmifolia Willd. 26

– Stems glabrous............................................................................................................................... 56

56 Leaf held at an angle of 45–90° relative to the petiole; stipules 10–35 mm long; styles irregularly multifid.................................................................................... B. glauca (Klotzsch) Ruiz & Pav. 66

– Leaf lamina continuing in the same direction as the petiole; stipules 4–14 mm long; styles bifid ... ....................................................................................................................................................... 57

57 Inflorescence branching 6–8 times; staminate tepals 2–2.5 mm long; bracts and bracteoles elliptic to ovate.......................................................................................................... B. peruviana A.DC. 68

– Inflorescence branching up to 4 times; staminate tepals 10–14 mm long; bracts and bracteoles broadly-ovate ................................................................... B. yuracyacuensis Moonlight sp. nov. 69

58 Pistillate flowers with 2 tepals ....................................................................................................... 59

– Pistillate flowers with 3 to 5 tepals................................................................................................ 65

59 Staminate flowers with> 20 stamens ............................................................................................ 60

– Staminate flowers with 6–12 stamens............................................................................................ 64

60 Petioles glabrous, rarely-glandular pilose...................................................................................... 61

– Petioles sparsely to densely pilose, never glandular-pilose........................................................... 63

61 Stipules persistent; first pair of bracts equal in size to subsequent bracts, <10 mm long................. ............................................................................................................... B. subspinulosa Irmsch. 25

– Stipules deciduous; first pair of bracts, larger than subsequent bracts,> 20 mm long.................. 62

62 Leaf margins ciliate; stipules twice as long as broad; first two inflorescence bracts not fused......... ....................................................................................................................... B. bracteosa A.DC. 10

– Leaf margins aciliate; stipules at least two thirds as broad as long; first two inflorescence bracts fused to form a cyathium ........................................................... B. cyathophora Poepp. & Endl. 11

63 Stipules deciduous, lanceolate; largest fruit and ovary wing entire at the apex; tepals glabrous...... ................................................................................................................. B. lamolina Moonlight 13

– Stipules persistent, reniform to ovate; largest fruit and ovary wing notched at the apex; tepals pilose on the outer surface....................................................................................... B. lophoptera Rolfe 14

64 Stipule margins entire; leaf margins entire to serrulate ........... B. longinqua Moonlight sp. nov. 15

– Stipule margin lacerate at the base, entire at the apex; leaf margins irregularly double dentate....... ............................................................................................ B. serratistipula Moonlight sp. nov. 17

65 Leaf laminae deltoid ...................................................................................................................... 66

– Leaf laminae variously elliptic, lanceolate, oblanceolate, ovate, obovate, oblong-ovate, broadlyovate, or reniform but never deltoid .............................................................................................. 67

66 Tepals white to pink; fruit wings ascending .................................................. B. fischeri Schrank 29

– Tepals brown or orange; fruit wings not ascending.................... B. deltoides Moonlight sp. nov. 21

67 Stem rooting at the lower nodes .................................................................................................... 68

– Stem not rooting at the lower nodes .............................................................................................. 69

68 Internodes with a dense, long-villous indumentum; upper leaf lamina dark green flushed black; staminate flowers 20–40 mm across; fruit and ovary wings lacking or semi-circular ...................... ....................................................................................................................... B. pastoensis A.DC. 1

– Internodes tomentose; upper leaf lamina uniformly pale green; staminate flowers 8–18 mm across; fruit and ovary wings oblong to triangular ........................... B. pedemontana Moonlight sp. nov. 2

69 Stem and petioles with an indumentum of stellate hairs or peltate scales..................................... 70

– Stem and petioles glabrous or with an indumentum of simple hairs............................................. 71

70 Stem and petioles with an indumentum of stellate hairs ................................... B. andina Rusby 43

– Stem and petioles glabrous or with simple hairs ....................................... B. unilateralis Rusby 44

71 Staminate flowers with 4 tepals ..................................................................................................... 72

– Staminate flowers with 2 tepals ..................................................................................................... 74

72 Leaves with 4–6 veins from the base; margin crenate.................................. B. arrogans Irmsch. 50

– Leaves with 6–8 veins from the base; margin serrate or dentate................................................... 73

73 Leaf margins acuspidate; staminate flowers 1.2–1.6 cm across; tepals of the staminate flowers with rounded apices; pistillate flowers ebracteolate ................... B. piurensis L.B.Sm. & B.G.Schub. 47

– Leaf margins with 2–5 cusps along the largest side; staminate flowers 4.4–9 cm across; tepals of the staminate flowers with acuminate apices; pistillate flowers bracteolate...................................... .................................................................................................. B. velata L.B.Sm. & B.G.Schub. 48

74 Stipule margins ciliate, at least at the base .................................................................................... 75

– Stipule margins aciliate throughout ............................................................................................... 78

75 Stipule margin lacerate at the base, entire at the apex; pistillate tepals 2 or 3 .................................. ............................................................................................ B. serratistipula Moonlight sp. nov. 17

– Stipule margins entire; pistillate tepals 5....................................................................................... 76

76 Lower leaf surface sparsely villous; leaf veins palmate ...................................... B. hirtella Link 30

– Lower leaf surface glabrous; leaf veins palmate-pinnate .............................................................. 77

77 Stem glabrous; inflorescence with up to 8 flowers; staminate flowers with 8–10 stamens............... ....................................................................................................................... B. humilis Dryand. 27

– Stem densely hispid; inflorescence with up to 48 flowers; staminate flowers with ca 25 stamens ... ...................................................................................................... B. nunezii Moonlight sp. nov. 67

78 Tepal apices acuminate or long-acuminate; tepals bright red or orange........................................ 79

– Tepal apices truncate, rounded, obtuse, or acute; tepals white, pink, brown, or orange ............... 80

79 Stipules late-deciduous to persistent, 12–35 mm long; leaves lanceolate to ovate ........................... ......................................................................................... B. stenotepala L.B.Sm. & B.G.Schub. 24

– Stipules deciduous, 8–12.4 mm long; leaves elliptic to oblanceolate ............................................... ................................................................................................ B. longitepala Moonlight sp. nov. 22

80 Styles irregularly multifid.............................................................................................................. 81

– Styles bifid ..................................................................................................................................... 83

81 Stipules deciduous; leaf laminae reniform, apices indistinct; leaf venation palmate; stamens> 60. .............................................................................................................. B. amoeboides Moonlight 9

– Stipules persistent; Leaf laminae lanceolate to ovate, apices distinct; leaf venation palmate-pinnate; stamens <30 .................................................................................................................................. 82

82 Stipules symmetrical, base cuneate; leaf margins irregularly double dentate ................................... ................................................................................................................ B. obtecticaulis Irmsch. 16

– Stipules asymmetrical, auriculate on the broad side, cuneate on the narrow side; leaf margins serrulate........................................................................................ B. vargasii Moonlight sp. nov. 18 83 Leaf laminae broadly-ovate; bracteole margins entire, aciliate; largest fruit wing contorted, angled 90° downwards .............................................................. B. brevicordata L.B.Sm. & B.G.Schub. 20

– Leaf laminae lanceolate to ovate; bracteole margins serrulate to serrate, ciliate; largest fruit wing not contorted.................................................................................................................................. 84

84 Leaf laminae lanceolate, apices acuminate.................................................... B. lucifuga Irmsch. 23

– Leaf laminae ovate, apices obtuse to acute.................................................................................... 85

85 Stipules persistent, ovate; leaf margins serrate...................................... B. subspinulosa Irmsch. 25

– Stipules deciduous, elliptic; leaf margins serrulate ............................. B. alto-peruviana A.DC. 19

Figures

Fig. 2. Venation in Peruvian Begonia. A. Pinnate venation (B. yaracuyensis Moonlight). B. Pinnate venation, 3-veined from the base (B. glabra Aubl.). C. Palmate-pinnate venation (B. obtecticaulis Irmsch.). D. Palmate venation with one primary vein (B. stenotepalaL.B.Sm. & B.G.Schub.).E. Palmate venation (B. lamolina Moonlight). F. Peltate venation with one primary vein (B. acerifolia Kunth.). G. Peltate venation (B. joshii Moonlight). Primary veins are shown in white, secondary veins from the petiole insertion in blue, and secondary veins from the primary veins in green. Photographs taken by D.A. Purvis & P.W. Moonlight in the living collections of the Royal Botanic Garden Edinburgh.