Cladium mariscus

Primary tabs

Cladium mariscus

Description

Coarse, glabrous. Leaves about as long as the stems, rigid, tough, complicate at the base, spinuloseserrulate on the margins and keel, 6-12 mm wide, gradually narrowed into a long triquetrous acumen with sharply cutting edges; Panicle decompound, oblong, interrupted, 30-50 cm long;

Distribution

Africa present, Asia-Tropical, Europe present, N. America present, temperate Asia present, tropical regions of the whole world present
Widely distributed over the tropical regions of the whole world, also in temperate Asia, Europe, Africa, and N. America, in Malesia very rare.

Notes

Up to now the numerous attempts to divide this polymorphic species into subspecies or microspecies have not been very successful. , split it up into 5 species, as follows:
  • 1a. Stigmatic branches 4-6; spikelets rather palecoloured. C. leptostachyum NEES & MEY.
  • b. Stigmatic branches 2-3; spikelets brown to rusty- or dark brown. 2
  • 2a. Nut smooth, shining; partial panicles dense. 3
  • b. Nut rather prominently tessellately rugose; partial panicles often loose. 4
  • 3a. Nut acuminate or beaked; culms not branched; rhizome long-creeping. C. mariscus (L.) POHL
  • b. Nut obtusely rounded at tip; culms with leafy branches in upper part; rhizome short (always?). C. procerum S. T. BLAKE
  • 4a. Nut acuminate; common rachis of panicle deeply canaliculate with scabrous margins; a rather slender plant from China and Japan. C. chinense NEES
  • b. Nut acute but scarcely acuminate; common axis not channelled, smooth; a stout American plant. C. jamaicense CRANTZ

C. leptostachyum , from Hawaii, was described by NEES as having 2 stigmas. In the Hawaiian specimens I examined I usually found 3 stigmas, more rarely 2 or 4. This varying number of stigmas I also found in European and Asian speci- mens. In my opinion C. leptostachyum can not be upheld as a separate race or species.
I fail to see the difference in the shape of the nut between Chinese or Japanese specimens and American ones. In several of the latter the nuts are certainly more acuminate than in the former. The slight difference in the rachis, even if holding good in all cases, seems insufficient for specific or racial discrimination.
C. mariscus s.s (C. germanicum SCHRAD.) is apparently a well-characterized subspecies, confined to Europe, E. Asia, and parts of Africa. The shining dark brown to blackish nuts measure 3-4 by 1½- 2 mm, the spikelets are 3-4 mm long, and the connective of the anthers is conspicuously produced.
C. procerum (C. mariscus subsp. intermedium ) has the small fruits of C. jamaicense and C. chinense, but they are quite smooth and somewhat rounded at the top. The same type of nut is met with in S. African specimens, which KÜKENTHAL referred to C. mariscus subsp. jamaicense.
In several respects the Malesian specimens are intermediate between the Australian and E. Asian ones. The nuts measure 2-2½ by 1⅓-1⅔ mm, they are more or less pitted-rugulose (much less than in the E. Asian specimens), and acute to distinctly acuminate. The stems often produce tufts of leaves or leafy branches breaking through the base of the leaf-sheaths finally falling off and quickly producing new clones. This feature, common in Australian plants and also observed in Japanese ones (), I found also in a Hawaiian collection.
As no sharp lines can be drawn it seems advisable to follow KÜKENTHAL, who divided C. mariscus into 3 subspecies, viz subsp. mariscus, subsp. jamaicense (incl. C. leptostachyum and C. chinense), and subsp. intemedium. The Malesian specimens may provisionally be referred to subsp. jamaicense.

Citation

STEEN. 1932: Arch. Hydrobiol.: 281
F.-VILL. 1882: Nov. App.: 309
Clarke 1894 – In: Fl. Br. Ind.: 673
Benth. 1878 – In: Fl. Austr.: 402
KÜK. 1942 – In: Fedde, Rep. 51: 185
BOECK. 1874 – In: Linnaea: 232
KUNTH 1837 – In: En.: 303