Caulerpa Lamouroux

Coppejans, Eric, Leliaert, Frederik, Verbruggen, Heroen, de Clerck, Olivier, Schils, Tom, de Vriese, Thomas & Marie, Daniel, 2004, The marine green and brown algae of Rodrigues (Mauritius, Indian Ocean), Journal of Natural History 38 (23), pp. 2959-3020 : 2978-2979

Caulerpa Lamouroux

Key to the species from Rodrigues

Prostrate branches are called stolonoids, erect branches assimilators, their main axis rachis, the compressed parts fronds and the side branchlets ramuli.

1 Assimilators strap-like................... 2

– Assimilators not strap-like.................. 3

2 Assimilators rather broad (3–10 mm), fleshy, unbranched or (pseudo-)dichotomously branched, with almost smooth to regularly short-toothed margin.. C. brachypus

– Assimilators narrow (2 mm), (pseudo-)dichotomously branched, mostly spirally twisted (but sometimes branched in a single plane); marginal teeth well-marked and serial................... C. serrulata

3 Ramuli either peltate or vesiculate (spherical, clavate or turbinate)...... 4

– Ramuli filiform or spiny or with pinnate aspect........... 9

4 Ramuli peltate (stalk-like lower portion abruptly expanded into a horizontally spread structure)....................... 5

– Ramuli not peltate but vesicle-like............... 7

5 Peltate structures singly on the stolonoids.......... C. peltata

– Peltate structures grouped.................. 6

6 Peltate structures randomly radially arranged around the central rachis...................... C. racemosa var. peltata

– Peltate structures bearing other peltate structures at the margin of the circular fronds or from their central part.............. C. numullaria

7 Ramuli densely packed and randomly radially arranged around the central rachis, the basal ones cylindrical, becoming clavate higher up and pear-shaped at the top of the assimilators.............. C. racemosa var. laetevirens

– All ramuli (sub-)spherical.................. 8

8 Stolonoids thin, elegant, ramuli 1.5 mm in diameter, stalk-like portion of the ramuli markedly constricted; vesiculate ramuli¡on longitudinal rows... C. lentillifera

– Stolonoids fleshy, with a stout habit; assimilators either short (1–2 cm), bearing only a few ramuli, resulting in a prostrate thallus or longer and bearing numerous ramuli; spherical part of the ramuli 1–2 mm wide (or more), shortly stipitate...................... C. racemosa var. racemosa

9 Assimilators pinnate (ramuli on two opposite, longitudinal rows)..... 10

– Assimilators not pinnate (ramuli on three longitudinal rows or randomly radially arranged around the central rachis).............. 14

10 Ramuli compressed, sickle-shaped, upwardly curved......... 11

– Ramuli cylindrical, upwardly curved.............. 12

11 Ramuli slightly constricted at the base, with straight parallel sides in the middle part, upwardly curved and gradually tapering into a spine at the apex; ramuli not overlapping................... C. taxifolia

– Ramuli markedly wider in the middle part, without parallel sides, rather abruptly tapering into an upwardly curved terminal spine; ramuli frequently touching or even overlapping in their widest part............ C. mexicana

12 Total width of the assimilators generally 10–15 mm (rarely down to 7 mm)...................... C. sertularioides

– Total width of the assimilators not exceeding 4 mm ......... 13

13 Ramuli up to twice as long as the diameter of the rachis................... C. cupressoides var. lycopodium f. disticha

– Ramuli generally three to four (but up to six) times as long as the diameter of the rachis........... C. cupressoides var. lycopodium f. elegans

14 Ramuli in three longitudinal rows (at least in part of the assimilators).................. C. cupressoides var. cupressoides

– Ramuli randomly radially arranged around the central rachis...... 15

15 Stolon without ramuli; ramuli of the assimilators rather long C. sertularioides f. farlowii

– Stolon also covered by short ramuli; ramuli of assimilators short, resulting in a spongy aspect.................... 16

16 Ramuli unbranched................ C. lanuginosa

– Ramuli dichotomously or subdichotomously branched..... C. webbiana