Cladodium, Bridel, 1826

Spence, John R., 2020, Studies in Austral Bryaceae (Bryopsida) I. New Combinations in Ptychostomum Hornsch. from southern South America, Phytotaxa 437 (2), pp. 60-65 : 63

Subgenus Cladodium

1. Plants large, stems often>2 (6) cm, mostly evenly foliate (intermediate plants key here)................................................................2

- Plants small, stems mostly <1(2) cm, comose-tufted or rarely evenly foliate ...................................................................................8

2. Leaves strongly and distinctly decurrent (except for depauperate material from harsh climates), ovate; sexuality dioicou............... ............................................................................................................................................................................. P. pseudotriquetrum

- Leaves not or only weakly decurrent, ovate to ovate-lanceolate or lingulate; sexuality dioicous, synoicous or autoicous ..............3

3. Costa percurrent or short-excurrent as mucro; sexuality dioicous or synoicous................................................................................4

- Costa excurrent in distinct medium to long awn; sexuality dioicous, autoicous or synoicous ..........................................................9

4. Leaf margins plane, limbidium lacking....................................................................................................................... P. zeballosicum

- Leaf margins recurved, at least proximally, limbidium present, distinct ...........................................................................................5

5. Sexuality dioicous; distal leaf margins serrulate; capsule erect to suberect, thick-necked, spores 10–15 µm .......... P. orthothecium

- Sexuality synoicous or autoicous; distal leaf margins smooth to serrulate; capsule mostly nodding to inclined, neck slender, tapering into seta; spore size various but often> 20 µm ...................................................................................................................................6

6. Leaves narrowly ovate-lanceolate; sexuality autoicous; cilia absent, endostome adherent to exostome; spores 22–26 µm ............... ........................................................................................................................................................................................... P. gayanum

- Leaves ovate; sexuality synoicous; peristome well-developed; cilia present, exostome and endostome free, spores <20 or> 30 µm ............................................................................................................................................................................................................7

7. Capsule mouth straight; fertile shoots unisetose, peristome well developed, spores 12–16 µm .......................................... P. bimum

- Capsule mouth oblique; fertile shoots often bisetose; peristome reduced, cilia absent, basal membrane low, spores 30–36 µm ....... .......................................................................................................................................................................................... P. dicarpum

8. Costa short excurrent as mucro, limbidium weak to absent; sexuality synoicous ............................................................... P. donatii

- Costa usually medium to long-excurrent in awn, limbidium present although sometimes obscure; sexuality dioicous, autoicous or synoicous ............................................................................................................................................................................................9

9. Sexuality synoicous or dioicous; spores size from 10–40 µm, plants strongly short comose-tufted, capsule pyriform to elongateclavate; wet to dry sites ....................................................................................................................................................................10

- Sexuality autoicous; spores 16–20 µm, plants loosely tufted, stems somewhat elongate; capsule elongate-clavate; wetland sites ... ......................................................................................................................................................................................... P. pallescens

10. Sexuality synoicous, peristome well-developed, spores 10–16 µm ............................................................................ P. creberrimum

- Sexuality dioicous or synoicous, peristome well-developed to strongly reduced, spores>(18) 20 µm ..........................................11

11. Sexuality synoicous; endostome and exostome adherent giving teeth chambered appearance; capsule short-pyriform, mouth narrow............................................................................................................................................................................... P. pendulum

- Sexuality dioicous or synoicous; endostome and exostome free; capsule pyriform, short or long-necked to clavate, mouth narrow to wide ..............................................................................................................................................................................................12

12. Peristome well-developed, cilia well-developed or sometimes shortened but present, spores 18–40 µm .......................................13

- Peristome strongly reduced, cilia absent or strongly shortened, stub-like, spores 26–30 µm ..........................................................15

13. Synoicous, spores 18–24 µm, distal cells <60 µm, thin walled, cilia sometimes shortened or only 1–2 present................................ ......................................................................................................................................................................................... P. inclinatum

- Synoicous or dioicous; spores> 28 µm; distal cells often> 80 µm, often incrassate; 2–3 cilia present, well-developed ................14

14. Dioicous; distal laminal cells thin to firm-walled; spores (26) 30–36 µm .................................................................. P. pauperculum

- Synoicous; distal laminal cells distinctly incrassate, spores (28) 30–40 µm ........................................................... P. chorizodontum

15. Dioicous......................................................................................................................................................................... P. vernicosum

- Synoicous ................................................................................................................................................................... P. lamprochaete