Begonia sect. Casparya, Klotzsch (1854: 127), 1894

Jara-Muñoz, Orlando Adolfo, Richardson, James E. & Zabala-Rivera, Juan Carlos, 2021, Five new species and three new varieties of Begonia section Casparya endemic to Colombia, Phytotaxa 525 (4), pp. 258-280 : 260-261

Key to Begonia sect. Casparya in Colombia

1. Flowers with white or pink tepals; tepals always free and spreading to slightly projecting ..............................................................2

- Flowers with tepals red or orange; tepals fused, or when free projecting and forming a campanulate perianth .............................19

2. Staminate and pistillate flowers on separate inflorescence; fruit without an apical column, or a very short column (ca. 5 mm long)....................................................................................................................................................................................................3

- Staminate and female flowers on the same inflorescence; fruit with an apical column...................................................................10

3. Leaf laminae with the midvein oblique or straight to the petiole, with a dense indument; stipules green, pubescent, persistent; styles multifid ...............................................................................................................................................................................................4

- Leaves with the mid-vein straight to the petiole, glabrous or sparsely pubescent; stipules hyaline to greenish, mostly glabrous, deciduous; styles not divided or with one division near to the base ..................................................................................................7

4. Leaf laminae oblique to the petiole; fruit with the horns flattened or with wings .............................................................................5

- Leaf laminae straight with the petiole; fruit with unflattened horns ..................................................................................................6

5. Stems succulent, 8.5–9 mm in diameter; plants dioecious; fruits with horns flattened; growing in paramo....................................... .......................................................................................................................................................................... B. perijaensis sp. nov.

- Stems fibrous, <5.5 mm in diameter; plants monoecious; fruits 3-winged toward the apex; growing in montane forest................... .............................................................................................................................................................................................. B. trianae

6. Outer tepals of staminate and pistillate flowers pinkish abaxially; pistillate flowers with 5 tepals in in poorly differentiated whorls; fruits with the apex of the horns horizontally flattened; endemic to the Sierrra Nevada de Santa Marta ..................... B. chlorolepis

- Outer tepals of staminate and pistillate flowers white throughout; pistillate flowers with 6 tepals in two distinct whorls; fruits with the apex of the horns vertically flattened; endemic to the Serranía de Perijá ....................................................................... B. ursina

7. Leaf base essentially symmetrical, with a tuft of trichomes between the petiole and the lamina; stamens connivent, forming a fusiform structure ........................................................................................................................................................... B. solaniflora

- Leaf base asymmetric, without a tuft of trichomes between the petiole and the lamina; stamens connivent, forming a fusiform or cylindrical structure ............................................................................................................................................................................8

8. Leaves glabrous and reddish underneath; without trichomes on the midvein above; bracteoles of pistillate flowers longer than the ovary.................................................................................................................................................................................. B. aguilarii

- Leaves with a row of hairs on the midvein above, rarely reddish underside; bracteoles of the pistillate flowers shorter than the ovary in B. pax , unknown in B. diegoi ...............................................................................................................................................9

9. Outer tepals of pistillate flowers 10–16.5 × 3–7.3 mm; stamens connivent, forming a cylindrical structure; free part of the stamen connective curved outward; endemic to the Sierra Nevada de Santa Marta ............................................................ B. diegoi sp. nov.

- Outer tepals of pistillate flowers 4.8–9.9 × 1.4–2.8 mm; stamens connivent, forming a fusiform structure; free part of the stamen connective straight; endemic to the Serranía de los Yariguies, in the Eastern Cordillera ......................................................... B. pax

10. Young inflorescence enveloped by gamophyllous bracts; staminate flowers with 2 tepals............................................ B. gamolepis

- Young inflorescence not enveloped by gamophyllous bracts; staminate flowers with 4 tepals.......................................................11

11. Plants usually less than 40 cm tall; leaf laminae straight with the petiole; leaves of numerous forms, without one side of the base much larger than the other ................................................................................................................................................................12

- Plants usually more than 40 cm tall; leaf laminae oblique to the petiole; leaves ovate or oblong with one side of the base much larger than the other..........................................................................................................................................................................13

12. Branches upright; inflorescence bisexual or rarely bearing only staminate flowers; outer tepals of staminate flowers apiculate; tepals of pistillate flowers to 6 mm long .............................................................................................................................. B. urticae

- Branches diffuse; pistillate flowers in separate inflorescence to the staminate flowers; outer tepals of staminate flowers obtuse; tepals of pistillate flowers 9–14 mm long ............................................................................................................................ B. diffusa

13. Apex of the fruit horns curved upward; inflorescence a dichasial cyme, more than 5 times divided; fruit column <5mm long ........ ............................................................................................................................................................................................. B. cornuta

- Apex of the fruit horns apex slightly curved upward or not curved; inflorescence a dichasial cyme, less than 5 times divided; fruit column> 5mm long...........................................................................................................................................................................14

14. Stems and leaves with glandular and non-glandular hairs; pistillate flowers with 6 tepals .................................................. B. oleosa

- Stems and leaves glabrous or with non-glandular hairs; pistillate flowers with 4 or 5 tepals .........................................................15

15. Leaves narrowly ovate or lanceolate; peduncle pubescent, reddish-green or whitish-green ................... B. mamapachensis sp. nov.

- Leaves oblong or ovate; peduncle glabrous, light green or reddish-green.......................................................................................16

16. Leaves glabrous on the underside.....................................................................................................................................................17

- Leaves pubescent on the underside, at least on the veins.................................................................................................................18

17. Bracts deciduous; inflorescence unbranched; stamens connivent............................................. B. vinagrera var. vinagrera var. nov.

- Bracts sub-persistent; inflorescence branched; stamens slightly divergent............................ B. vinagrera var. pomecensis var. nov.

18. Leaves sometimes serrate-lobulate near to the base; inflorescence undivided, or once divided; pistillate flowers with entire outer tepals; fruit column longer than the horns......................................................................................................................... B. toledana

- Leaves with serrate margins; inflorescence twice divided; pistillate flowers with dentate outer tepals dentate; fruit column subequal to the horns ........................................................................................................................................................... B. galeanoi sp. nov.

19. Flowers with 4, 6, or 8 stamens, if 8 then the perianth in two series and at least one type of flower with the perianth fused ........20

- Flowers with more than 8 stamens, perianth free.............................................................................................................................32

20. Flowers with 4 stamens ....................................................................................................................................................................21

- Flowers with 6 or 8 stamens.............................................................................................................................................................27

21. Inflorescence with 6 to 9 bracts on each branch; perianth with one series ........................................................................... B. oliveri

- Inflorescence with less than 6 bracts per branch; perianth with two series, at least in the staminate flowers, the inner series much smaller than the outer one.................................................................................................................................................................22

22. Leaves bullate; flowers pubescent on the external surface .............................................................................................. B. lehmanni

- Leaves smooth; flowers glabrous .....................................................................................................................................................23

23. Leaves lanceolate; one perianth series in the pistillate flower ........................................................................................ B. irmscherii

- Leaves elliptic; two perianth series in the pistillate flowers.............................................................................................................24

24. Leaves with rigid hairs; tepals of pistillate flowers not fused ............................................................................................ B. suaviola

- Leaves with soft hairs; tepals of pistillate flowers fused..................................................................................................................25

25. Leaves long elliptic, pubescent with two types of hairs intermingled, one type long and not tuberculated, and the other type short and tuberculated............................................................................................................................................ B. kalbreyeri var. glabra

- Leaves elliptic, with only one type of pubescence...........................................................................................................................26

26. Young stems papillose-hirsute................................................................................................................. B. kalbreyeri var. kalbreyeri

- Young stems pubescent or glabrous ....................................................................................... B. kalbreyeri var. orquidensis var. nov.

27. Stipules persistent; Inflorescence with 8-10 bracts; tepals of the staminate flowers yellow; stamens in two series of 4, with different lengths, receptacle black................................................................................................................................................... B. killipiana

- Stipules persistent or deciduous; Inflorescence with <8 bracts; tepals of the staminate flowers, red, pink or white, stamens all the same length.......................................................................................................................................................................................28

28. Adaxial surface of the leaves with a series of long hairs between each pair of secondary veins. perianth of the staminate flowers with the limb reflexed and 6-lobulate; stamens 8; apical column of the fruit <4 mm long .......................................... B. longirostris

- Adaxial surface of the leaves with series of hairs, with uniform pubescence or glabrous; perianth of the staminate flowers with the limb erect, with two big lobules each one rounded or retuse; stamens 6; apical column of the fruit longer (> 4 mm long ................. ..........................................................................................................................................................................................................29

29. Petiole oblique to the lamina; leaf margins serrated-lobulated ........................................................................................ B. hexandra

- Petiole straight to the lamina; leaves margins serrate or biserrate ...................................................................................................30

30. Stems, leaves, flowers and fruits tuberculate-pilose or hispidous.......................................................................................... B. libera

- Stems, leaves, flowers and fruits glabrous or glabrescent................................................................................................................31

31. Petioles 1.8–3.9 (13.3) mm long ...................................................................................... B. silverstonei var. brevipetiolata var. nov.

- Petioles 5.4–30.6 mm long ................................................................................................................. B. silverstonei var. silverstonei

32. Large and scandent plants (usually> 40 cm tall) with pendulous inflorescences; perianth campanulate ........................................33

- Small and erect plants (usually <40 cm tall) with erect inflorescences; perianth campanulate or with the tepals spreading..........34

33. Stipules persistent; staminate inflorescence umbel-like; stamens with long projecting connective; pistillate inflorescence uniflorous; fruit horns with the apex slightly curved forward, and apical column absent................................................................ B. ferruginea

- Stipules deciduous; Staminate inflorescence cymose; stamens without a projecting connective; pistillate inflorescence cymose with numerous flowers; fruit horns with the apex slightly curved upward, and with apical column present................. B. umbellata

34. Pistillate flowers in the same inflorescence as the staminate ones, or inflorescence bearing only staminate flowers; tepals spreading or projecting slightly upward, red, pink or white. ................................................................................................................ B. urticae

- Pistillate flowers solitary; tepals projecting upward, red .................................................................................................................35

35. Young stems densely pubescent; stamens on a long torus, anthers without connective projecting; pistillate flowers with 5 tepals; fruit with a long and persistent apical column, subequal to the horns ........................................................................ B. antioquensis

- Young stems sparsely puberulous; stamens not emerging from a torus, anthers with an acute, projecting connective; pistillate flowers with 6 tepals; fruit with a short and deciduous apical column, shorter than the horns ................................... B. colombiana