1. Leaves polystichous or spiralling, not distichous - > 2

1a Leaves distichous - > 17

2. Plant sterile, without inflorescence, stemmed, with 1 -1.5mm wide leaves, from coast of northern Chile to south Peru - > landbeckii

2a Plant not sterile, always with inflorescence - > 3

3. Flower bracts glabrous, seldom with wholely few and hardly visible scales - > 4

3a Flower bracts wholely or at least in the upper part clearly scaled - > 10

4. Flower bracts with few, hardly visible scales, 6-9-nerved, widest at the base; Sepals uniformly short connate (or the posterior pair somewhat higher), narrow triangular, blunt, 5-nerved; Petal dirty yellow; Leaf stiff erect, with clearly large nerves - > erecta

4a Flower bracts and sepals totally glabrous; Petals brown to coffee brown; Leaves edged, one clearly large nerve - > 5

5.Plant stemless or short stemmed; Leaves 15-45mm long, spreading, not densely imbricate - > 6

5a Plant clearly stemmed, Leaves under 15mm long, densely imbricate - > 7

6. Flower bracts mostly as long as the sepals; Plant robust; Leaves 20-45mm long, at the base 3-5mm wide - > funebris

6a Flower bracts mostly half as long as the sepals; Plant slender, Leaves mostly under 20mm long, 2-3mm wide at base, ± sharply acuminate; very seldom with distichous leaves - > rectangula

7. Flower bracts 5-6-nerved; Inflorescense almost always at anthesis clearly stemmed; sepals (4-)5-nerved - > 9

7a Flower bracts 1(-3)-nerved, mostly glabrous; Inflorescense at anthesis almost always not stemmed - > 8

8. Peduncle at fruiting mostly longer; sepals 3(-5)-nerved, glabrous, with a mid nerve continuously to the tip; petals violet. Plant diam 4-7mm - > pedicellata

8a Peduncle at fruiting not longer, sepals 5-6-nerved, 1/3 to 2/3 or the edges scaled; petals yellow; Plant in diam 3-5mm - > minutiflora (was bryoides)

9. Flower bracts oval; sepals at widest or above the middle, 5.6–6.5mm long; petals yellowish or brownish. - > aizoides

9a Flower bracts narrow triangular; sepals at the widest below the middle, sometimes scaled, 8.5 mm long; petals violet - > aff. aizoides (possibly a form of T. brealitoensis)

10. Flowers small, flower bracts (4-) 6-7 (-10) mm long, sepals 6-7 mm long. Inflorescense few flowered, seldom l-flowered, peduncle mostly present - > 11

10a Flowers large, Flower bracts (8.5-)10-18mm long, sepals (8-)9-14 mm long, Inflorescense mostly 1-2-flowered, seldom to 4-flowered, peduncle present or missing - > 13

11. Plant stemless or at least short stemmed - > 12

11a Plant clearly stemmed; peduncle mostly distinct, seldom missing. Leaves thin, tipped, appressed ("trlcholepis") or spreading. ("polytrichoides"), to 15mm long; petals yellow; Rhachis not geniculate - > tricholepis var tricholepis

12. Leaves strong, quite thick; Rhachis mostly geniculate; Petals yellow to orange yellow - > loliacea

12a Leaves thin, very slender, not thick, 20-50mm long; Rhachis not geniculate; Petals brown, seldom yellow - > tricholepis var macrophylla

13. Leaves to 15mm long, densely imbricate; Plant 4-10cm long, compact, stemmed - > 14

13a Leaves 20-60mm long, not densely imbricate; plant not compact, ± stemmed - > 15

14. lnflorescense sessile; Flower bracts 9-nerved, 12mm long; Sepals 11mm long; Petals 7-nerved brown yellow; Leaves spreading and bent outwards. Plant very short stemmed - > angulosa

14a Inflorescense clearly stemmed; flower bracts 11-12-nerved, 8.5–10.5mm long; Sepals 8-9mm long, Petals 5-7-nerved, violet; Leaves straight, erect. Plant clearly stemmed. - > brealitoensis

15. Leaves 3-5mm wide; Plant strong; epiphytc (seldom epilithic) in south Peru (Arequipa), Bolivia and Argentinia - > 16

15a Leaves 1–1.5mm wide; Plant erect delicate; terrestrial in sand or epiphytic in south Peru (Coast) und North Chile - > landbeckii

16. Leaves wide at base, edges not fused appressed scaled, 30-50mm long; Flower bracts 15-17-nerved; Sepals in the upper 40-70% large scaled; Petals dark violet - > gilliesii subsp polysticha

16a Leaves at base hardly wider that the middle, edges joined, ± erect scaled, 20-40mm long; flower bracts 12-13-nerved; Sepals in the upper 50-65% large scaled; Petals yellowish - > hirta (seldom polystichous Form)

17. Plant with longer thin internodes, hanging, to 8m long; Sepals glabrous or almost glabrous; Petals green, seldom yellow (in Peru and Ecuador) - > usneoides

17a Plant with compact stem, not with longer thin internodes, sometimes almost stemless, not over 30cm long; Petal never clear green, at the most brown green - > (mollis) 18

18. Leaves ± soft, 1.5-3mm Ø, round or almost round, without a distinct pungent tip; Flower mostly relatively small, Sepals 4.5-9(10.6)mm long; Plant mostly relatively slender (Exceptions: caliginosa, hirta and cotagaitensis Sepals 8-14mm long; also steps 19-22) - > 19

18a Leaves hard, often with clearly visible light Sclerenchyma, with pungent tip, 3-6mm Ø; Flowers relatively large, Sepals (8-)9-14mm long (compare with step 19); Plant strong, 5-30cm long - > 28

19. Plant strong and mid size to large, Leaves 2-4mm Ø, round or upper side concave, 4-14cm long, mostly with ± blunt tip; Flower relatively large, Sepals 8-14mm long, mostly distinct scaled - > 20

19a Plant small to mid size, slender erect, Leaves 1-3mm Ø, 0.5-10cm long; Flowers relatively small, Sepals 4.5-9mm long, abundantly glabrous - > 23

20. Plant large, 15-25cm long, short stemmed, Leaves often with glabrous sheath (seldom scaled), upper side somewhat concave, to 14cm long, a little bent; Flowers scented - > 21

20a Plant clearly stemmed, much smaller, 5-15cm long; Leaves 2-4cm long; Inflorescense with relatively short stem, peduncle 1-2mm Ø, 1-3(-4)cm long - > 22

21. Inflorescense 10-15cm long stem, 2-5-flowered; Petals yellow to yellow brown, seldom coffee-brown; Central Bolivian (Cochabamba) to south Argentina (Tucuman, La Rioja) - > caliginosa

21a Inflorescense to somewhat 3cm stemmed; Petals coffee-brown; mid Argentina (Catamarca, La Rioja, Buenos Aires) - > “myosura var saxicola”(= gilliesii “var saxicola” nom prov.)

22. Sepals similarly short connate, dense scaled; Plant clearly with erect scales - > hirta

22a Sepals posterior much higher connate (53-64%), sparingly scaled to almost glabrous; Plant a little erect scaled - > cotagaitensis

23. Below the flower of the inflorescense with 1-2 peduncle bracts directly under the flower bract - > 24

23a No peduncle bracts directly under the flower bract - > 27

24. Sepals glabrous; Plant ± stemless - > 25

24a Sepals ± clearly scaled; Plant clearly and to 26cm stemmed - > 26

25. Leaves slender (particularly in south Brazil and Paraguay), 0.5-1.5 mm Ø, 4-10 cm long; Sepals lanceolate to oval-lanceolate, ± tipped, (5.8-) 7.5-8.4 ( -9.6)mm long, (2.6-)3-3.5(-3.8)mm wide; Petals blue, seldom white; south USA to Argentina and Uruguay - > recurvata (polymorphous and not well organised!)

25a Leaves strong, 1.5-2mm Ø; Sepals obovate, tip rounded, (8-)9-10.6mm long, (4.2-)4.8-5.5mm wide; Petals dirty brown; Andes of south Peru (Dept . Ayacucho, Dept. Cuzco) - > aff. recurvata

26. Plant slender erect, Leaves thin and long; Inflorescense long stemmed, Chile and south Peru(?) Coast - > landbeckii

26a Plant strong erect, Leaves (2-)3mm Ø, dense white felt; Inflorescense sessile; south Bolivia (Dept. Tarija) - > mollis

27. Sepals wide lanceolate, mostly rounded at the tip, seldom acuminate or tipped, all ± clearly together connate, posterior a little higher connate than the anterior; flower bracts almost always glabrous - > capillaris s.l.(very polymorphous and not well organised!)

27a Sepals almost long and seemingly slender, side nerves clearly short, anterior Sepal almost free, posterior very high (to 80%) connate;flower bracts mostly wholely or in the upper third scaled, seldom glabrous (williamsii) - > virescens s.l.(very polymorphous and not well organised!)

28. Flower cleistogamous, Sepals wide ovate-lanceolate, blunt to rounded, almost free or the posterior wholely a little connate, 7-9-nerved, 7.5-8.5(-9)mm long, glabrous; Flower bracts glabrous (seldom with hardly visible few scales); Inflorescense mostly 2-flowered. Leaves hard, stiff, striped nerved, pungent - > castellanii

28a Flower not cleistogamous (T. hirta sometimes cleistogamous, however not obligatory); Bracts always scaled; Sepals 10-14mm long - > 29

29. Leaves very hard, with striking Sclerenchyma, Plant middle size, seldom large - > 30

29a Leaves without or with hardly visible sclerenchyma. - > 31

30. Plant stemless or short stemmed, Leaf sheath glabrous; Inflorescense sessile or very short stemmed; Sepals glabrous, equally almost free - > retorta

30a Plant clearly stemmed, Leaf sheath scaled; Inflorescense stemmed; Sepals scaled, posterior connate to the middle - > andicola

31. Leaf in cross-section round, not drawn together on the side - > 32

31a Leaf drawn together on the side, very dense, 2-4cm long, 4-5mm thick, appressed scaled. Peduncle mostly missing, seldom to 5(-10)cm long. Mid Argentina - > gilliesii subsp gilliesii

32 . Plant clearly stemmed; Leaves ± soft to moderately hard, mostly erect scaled - > 33

32a Plant ± stemless, at the most short stemmed; Leaves hard or soft, mostly ± appressed scaled - > 34

33. Posterior sepals more than half in length connate; Sepals glabrous or almost glabrous; Petals brown to dark violet - > cotagaitensis

33a Posterior sepals seldom and very little connate; Sepals 1/3 to 2/3 scaled; Petals yellow or yellowish - > hirta

34. Leaves hard, grey-green, crooked, at the tip but again bent forwards, 4-5mm Ø, to 10cm long; Sepals equally free - > myosura

34a Leaves relatively soft, arched, 2.5-3.5mm Ø, to 15cm long, mostly light green; posterior sepals to a ¼ connate, mostly however less - > mandonii

Derek Butcher, 29/07/15
Tillandsia nutters who are interested in the littlies....
Yes, the best things come wrapped in little parcels and I have always been fascinated in this Diaphoranthema group. The DVD contains much of the work of Walter Till who got his doctorate in 1984 when investigating this complex. He even sent me some plants for my collection and some of you are growing offsets from me. Many botanists do not have access to this DVD material and generally follow Smith & Downs.
It was with great surprise when me mate Oscar from Rio sent me the enclosed, published 2 years ago. It does show botany is never ending and only Argentinian material has been looked at. We know that this was the stamping ground for Chris Larson so many years go and the key given may help the inquisitive ones.

Click HERE for a 'PhytoKeys' research Article by Lucía V. Castello & Leonardo Galetto.
"How many taxa can be recognized within the complex Tillandsia capillaris (Bromeliaceae, Tillandsioideae)?
Analysis of the available classifications using a multivariate approach."