Seaweeds of the South African South Coast

1 a Thallus prostrate

2

1 b Thallus erect

9

2 a Utricles clearly visible to naked eye| 1.5-2.5 mm in diameter| thallus globose and light green

C. megalophysum

2 b Utricles not clearly visible to naked eye and less than 1 mm diameter| thallus smooth or velvety| various shapes

3

3 a Thallus circular in outline| more than 10 mm thick| globose; utricles longer than 1.5 mm| 350-520 µm diameter at apex

C. papenfussii

3 b Thallus with irregular outline

4

4 a Thallus dichotomously branched| mainly or entirely prostrate

C. prostratum

4 b Thallus not dichotomously branched

5

5 a Thallus strikingly membrane-like| 1.5–3 mm thick| loosely attached to substratum

C. pelliculare

5 b Thallus in mature parts usually thicker than 3 mm| applanate

6

6 a Thallus with well-developed more-or-less free lobes| utricles markedly ninepin-shaped

C. stephensiae

6 b Thallus attached on most of under-surface| utricles cylindrical or club-shaped

7

7 a Utricles mostly shorter than 1 mm| only edges of thallus free

C. lucasii subsp. capense

7 b Utricles mostly longer than 1 mm| thallus firmly attached to substratum over whole under surface

8

8 a Utricles without hairs| gametangia cylindrical to spindle-shaped

C. incognitum

8 b Utricles with abundant hairs| gametangia lanceolate-ovoid or flask-shaped

C. spongiosum

9 a Thallus flattened| up to several cm wide

C. platylobium

9 b Thallus completely cylindrical or largely cylindrical except sometimes for flattening at forkings

10

10 a Utricles markedly mucronate (pointed tips)

C. fragile subsp capense

10 b Utricles non-mucronate

11

11 a Branch forks of noticeably unequal length| giving thallu cervicorn appearance| branches uneven in width

C. pocockiae

11 b Branch forks of similar length| branches of even width but may narrow towards tips

12

12 a Thallus pale green| translucent at tips| markedly flattened at forkings

C. tenue

12 b Thallus dark green| not translucent at tips| terete or slightly compressed throughout

13

13a Utricles often longer than 1 mm

C. duthieae

13 b Utricles seldom as long as 1 mm

14

14 a Utricles capitate (milk-bottle shaped)| slender| with tiny pits

C. capitatum

14 b Utricles stout| cylindrical to club-shaped

15

15 a Utricles without hairs| thallus terete throughout| 3-6 mm diameter| not narrowing towards tips

C. isaacii

15 b Hairs or hair-scars common on utricles| thallus terete except for flattening near base| narrowing from 4-8 mm lower down to 1.5 - 2 mm near apices

C. extricatum