Catasetum, Rich.

Krahl, Dayse R. P., de Oliveira, Miguel S., Schmal, Philippe, da Silva, João B. F., Chiron, Guy, Krahl, Amauri H. & Cantuária, Patrick de C., 2025, Catasetum × humaitaense (Orchidaceae: Catasetinae), a new nothospecies from the Brazilian Amazon, Biota Colombiana 26, pp. 1-14 : 7

Key to the species and nothospecies of Catasetum with symmetrical and convergent antennae from the state of Amazonas, Brazil

1. Non-resupinate flowers……….…… C. kraenzlinianum

1’. Resupinate flowers………………..…...…...……………….2

2. Lip trilobed or subtrilobed………………….………….……3

2’. Lip entire…………………………………………..……………….4

3. Mid-lobe of the lip deltoid with a small acute callus……………….…………………..….…………… C. × sheyllae

3’. Mid-lobe of the lip oval and devoid of callosity………………………………….…... C. × humaitanense

4. Lip with fimbriae…………………………….…………………..5

4’. Lip without fimbriae…………………………….…………...7

5. Lip oblong………………………….…………………... C. krahlii

5’. Lip triangular, subtriangular or ovoid……….....…….6

6. Lip ovoid and densely fimbriated……………………….……... C. reichenbachianum

6’. Lip triangular to subtriangular with a sparsely fimbriate margin that is concentrated at the apex…………………………………………………..… C. rivularium

7. Margin of the lip crenate or denticulate……..………………………....…………… C. ivaneae

7’. Margin of the lip smooth………………………...…..……8

8. Lip oblong to lingulate………………….…….. C. tigrinum

8’. Lip obovate to oval or triangular to deltoid…...….9

9. Inflorescence arched to pendent; lip deeply concave; apex of lip without callus…………………..….…………………..………… C. pulchrum

9’. Inflorescence erect to arched; lip relatively flat with a slight depression near the base; apex of lip with callus………………………………………………………….…10

10. Apex of the lip ending in an obtuse to truncated callus...………..………………………………….... C. tenebrosum

10’. Apex of the lip ending in an acute callus…...………………………….....………………….. C. sophiae