Disa sect. Stenocarpa

Bytebier, Benny, 2015, Disa staerkeriana (Orchidaceae): a new species from Mpumalanga, South Africa, Phytotaxa 203 (2), pp. 192-198 : 195

Key to Disa sect. Stenocarpa

Linder & Kurzweil (1999) presented an artificial key to Disa sect Stenocarpa . Since then, the circumscription of this section has changed ( Bytebier et al. 2008) and two new species have been described, Disa vigilans and this new taxon. Thus, we present an updated key to this section below.

1a. Leaves radical, hysteranthous.............................................................................................................................................................2

1b. Leaves cauline, green at anthesis........................................................................................................................................................5

2a. Galea as deep as long; flowers red or orange, spur as long as or longer than the median sepal........................................................3

2b. Galea longer than deep, laterally flattened; flowers white, pink or blue............................................................................................4

3a. Spur longer than 20 mm, ascending .................................................................................................................................. D. porrecta

3b. Spur shorter than 20 mm, horizontal .............................................................................................................................. D. ferruginea

4a. Spur longer than the lateral sepals; flowers mauve ................................................................................................................ D. arida

4b. Spur shorter than the lateral sepals; flowers white to pink.......................................................................................... D. gladioliflora

5a. Spur 25–45 mm long..........................................................................................................................................................................6

5b. Spur less than 25 mm long.................................................................................................................................................................7

6a. Sepals more than 13 mm long; from Mpumalanga ............................................................................................................ D. amoena

6b. Sepals less than 13 mm long; from KwaZulu-Natal, Lesotho or Eastern Cape ..................................................................... D. nivea

7a. Leaves soft; plants usually flexuose;..................................................................................................................................................8

7b. Leaves rigid; plants rarely flexuose (except D. oreophila )................................................................................................................9

8a. Sepals less than 10 mm long ............................................................................................................................................. D. saxicola

8b. Sepals more than 15 mm long ............................................................................................................................................ D. aristata

9a. Inflorescence capitate or subcapitate.............................................................................................................................. D. cephalotes

9b. Inflorescence a lax or dense spike....................................................................................................................................................10

10a. Spur 2.5–5 mm long; flowers blue or pale mauve with darker veins...............................................................................................11

10b. Spur 5–20 mm long; flowers pink or white.....................................................................................................................................12

11a. Sepals 7–13 mm long; flowers pale mauve............................................................................................................. D. dracomontana

11b. Sepals 4–5 mm long; flowers blue ........................................................................................................................................ D. stricta

12a. Sepals less than 10 mm long; plants flexuose ................................................................................................................. D. oreophila

12b. Sepals more than 10 mm long; plants not flexuose..........................................................................................................................13

13a. Median sepal 10–18 mm long..........................................................................................................................................................14

13b. Median sepal 20–30 mm long ............................................................................................................................................ D. pulchra

14a. Leaves more than 6 mm wide; ovaries more than 20 mm long......................................................................................... D. montana

14b. Leaves less than 5 mm wide; ovaries less than 18 mm long............................................................................................................15

15a. Median sepal less than 7 mm wide..................................................................................................................................... D. vigilans

15b. Median sepal more than 9 mm wide ........................................................................................................................... D. staerkeriana