Staurogyne, Wallich, 1831

Braz, Denise Monte & Monteiro, Reinaldo, 2017, Taxonomic Revision of Staurogyne (Nelsonioideae, Acanthaceae) in the Neotropics, Phytotaxa 296 (1), pp. 1-40 : 5-6

Key to the species of Neotropical Staurogyne

1. Flowers in a bracteate inflorescence; corolla infundibular, 4 − 16.5(− 27) mm long, white to purple, sometimes the limb and throat with purple or vinaceous spots...........................................................................................................................................................2

- Flowers in bracteate or leafy inflorescence; corolla tubular, 16 − 47 mm long, red or yellow..........................................................18

2. Bracts and bracteoles subulate, truncate at base; bracts, bracteoles and calyx whitish; corolla 19 − 27 mm long; stigma subcrateriform ................................................................................................................................................................................. S. guianensis

- Bracts and bracteoles elliptic, lanceolate, obovate, rarely bracteoles linear, both narrow at base;bracts, bracteoles and calyx green, red or yellow; corolla 4 − 16.5 mm long; stigma distintinctly 2-divided.............................................................................................3

3. Panicles densely branched, with corymbiform subunits ................................................................................................... S. fastigiata

- Spikes or racemes, rarely panicles lax, not corymbiform..................................................................................................................4

4. Leaf blade linear or linear-lanceolate, at least ten times as long as wide....................................................................... S. stolonifera

- Leaf blade with other forms, shorter..................................................................................................................................................5

5. Plant creeping, densely branched.......................................................................................................................................................6

- Plant erect, rarely branched................................................................................................................................................................9

6. Leaf blade ovate-elliptic to suborbicular............................................................................................................................................7

- Leaf blade lanceolate, ovate-lanceolate, oblong-lanceolate or oblong-ovate.....................................................................................8

7. Leaves sessile to subsessile; inflorescences terminal and axillary, elongate; calyx ciliate ............................................ S. miqueliana

- Leaves petiolate, petiole 4 − 5.8 mm long; inflorescence terminal, subcapitate; calyx not ciliate .................................... S. trinitensis

8. Branches and leaves lax; glandular trichomes absent on rachis, bracts, bracteoles and calyx........................................... S. spraguei

- Branches and leaves dense; glandular trichomes present on rachis, bracts and bracteoles, rarely present in the calyx ....... S. repens

9. Inflorescence terminal and subcapitate ....................................................................................................................... S. veronicifolia

- Inflorescence terminal and axillary, elongated.................................................................................................................................10

10. Leaf blade 1.1 − 5.0 cm long..............................................................................................................................................................11

- Leaf blade longer than 5.2 cm ..........................................................................................................................................................12

11. Plant sparsely branched; flowers opposite at the base and becoming alternate soon above along the rachis; corolla 4.5 − 5.9 mm long............................................................................................................................................................................. S. diantheroides

- Plant densely branched, flowers always opposite along the rachis; corolla 6 − 9.3 mm long .......................................... S. euryphylla

12. Leaf blade oblong-lanceolate to narrowly lanceolate (at least six times longer than wide)................................... S. lepidagathoides

- Leaf blade elliptical or ovate-lanceolate (up to four times longer than wide)..................................................................................13

13. Leaves entirely pilose on both surfaces.................................................................................................................................. S. parva

- Leaves glabrous to glabrescent on the upper surface, lower surface with trichomes restricted to the veins...................................14

14. Bracts colored...................................................................................................................................................................................15

- Bracts green......................................................................................................................................................................................16

15. Petiole 0.8 − 2.1 cm long; bracts broad-elliptic to suborbicular, 3.3 − 5.6 mm broad................................................... S. mandioccana

- Petiole 2.1 − 6.3 cm long; bracts elliptic to lanceolate-elliptic, 0.8 − 2.8 mm broad............................................................ S. sylvatica

16. Glandular trichomes absent on rachis, bracts, bracteoles and calyx ......................................................................................... S. alba

- Glandular trichomes present on rachis, bracts, bracteoles and calyx...............................................................................................17

17. Petiole 7 − 12 mm long; inflorescence up to 3.3 cm long; bracts 9.5 − 10.1 × 3.5 − 5 mm ................................................. S. riedeliana

- Petiole 1 − 4.2 cm long; inflorescence 2.5 − 11.5 cm long; bracts 4.7 − 8.5 × 1.5 − 3 mm ..................................................... S. eustachya

18. Corolla red........................................................................................................................................................................................19

- Corolla yellow to greenish-yellow...................................................................................................................................................20

19. Raceme spiciform, dense; bracts and bracteoles red to purple........................................................................................... S. itatiaiae

- Raceme lax; bracts and bracteoles green.......................................................................................................................... S. rubescens

20. Panicles terminal and axillary .......................................................................................................................................... S. brachiata

- Racemes terminal and/or axillary.....................................................................................................................................................21

21. Inflorescence bracteate.....................................................................................................................................................................22

- Inflorescence leafy............................................................................................................................................................................26

22. Bracts and bracteoles colored; bracts 3 − 7 acrodromous nerved......................................................................................................23

- Bracts and bracteoles green; bracts 1-nerved or 3- nerved...............................................................................................................24

23. Glandular trichomes restricted to the corolla, rarely occurring in the calyx; corolla 2.4 − 2.8 cm long, yellow to greenish toward the lobes, lobes densely pubescent ................................................................................................................................... S. anigozanthus

- Glandular trichomes present in all reproductive parts; corolla 3.5 − 4.7 cm long, yellow, lobes sparsely hairy.................. S. elegans

24. Glandular trichomes restricted to the corolla and fruit, rarely present on the calyx ......................................................... S. minarum

- Glandular trichomes present in the whole plant...............................................................................................................................25

25. The whole plant sparsely pilose; inflorescence lax, with bracts soon distinct distally in form, size and venation from the leaves .... .................................................................................................................................................................................................. S. flava

- The whole plant densely hirsute; inflorescence dense; leaves gradually reduced into bracts distally................................. S. hirsuta

26. Leaves lanceolate, 1.8 − 6× 0.5 − 1.3 cm; petiole 3 − 8 mm long ............................................................................................ S ericoides

- Leaves elliptic to ovate, 4.4 − 14.5 × 2 − 6 cm; petiole 6 − 23 mm long...............................................................................................27

27. Pedicel 3.4 − 11 mm long; posterior segment of the calyx 16 − 20 × 3 − 4.5 mm .......................................................... S. warmingiana

- Pedicel 12 − 17 mm long; posterior segment of the calyx 6.9 − 15 × 3 − 6 mm .............................................................. S. vauthieriana