Cotula

Scientific name

Cotula L.

Common names

waterbuttons, brass-buttons, watergrass, stagger weed, slender buttons

Family

Asteraceae

Similar genera

Cadiscus, Eriocaulon (to C. myriophylloides)

Native distribution

southern Africa, Australia

Species cultivated

Cotula coronopifolia L.

Adventive distribution

Cotula coronopifolia is introduced to Europe, North and South America.

Weed status

not weedy

Habit

emergent emergent:
(adj) (syn. emersed) with parts raised out of the water; extending up out of the water
herb, creeping to decumbentdecumbent:
(adj) (of stems) having a portion lying along the ground, with upper parts erect or ascending
or erect

Brief description

Perennial, rooting at lower nodes. Leaves alternatealternate:
(adj) (of leaves) bearing one leaf per node; placed singly on the stem at different heights
; sessilesessile:
(adj) attached directly, without a stalk
, stem-clasping with a sheathing base; leaf bladeblade:
(n) (syn. lamina) the flat, expanded part of a leaf, frond, or petal (excluding, e.g., the petiole)
thickened, linear, ellipticelliptic:
(adj) in the form of an ellipse (oval)
to ovateovate:
(adj) egg-shaped in outline; generally with the broad end at or near the base
, variably dissecteddissected:
(adj) (of leaves) +/- deeply divided, cut, or lobed, including being compound
, faces gland-dotted; venationvenation:
(n) the arrangement of veins in a leaf
typically obscure or midribmidrib:
(n) the main or central vein, line or rib in a leaf or perianth segment
. Inflorescenceinflorescence:
(n) the arrangement of flowers on the floral axis
axillaryaxillary:
(adj) in, of, or produced from an axil
heads, pedunculatepedunculate:
(adj) borne on or possessing a peduncle
; phyllariesphyllaries:
(n) an individual bract of the involucre in Asteracea flower heads
in 2-3 rows, subequal. Ray florets female, absent or reduced, white if present; disk florets bisexualbisexual:
(adj) having both male and female sexual reproductive structures on one individual or in one flower
, corollacorolla:
(n) the inner whorl(s) of the perianth; all the petals of a flower
tubular, 4-lobed, yellow. Cypselacypsela:
(n) fruit typical of the Asteraceae, it develops from an inferior ovary and includes noncarpellary tissue (similar to an achene)
of ray floretfloret:
(n) one of the small individual flowers within a dense cluster of flowers, as in a compound inflorescence and in grass spikelets
winged, papillate; inner floretfloret:
(n) one of the small individual flowers within a dense cluster of flowers, as in a compound inflorescence and in grass spikelets
wings absent or narrow, without papillaepapillae:
(n) (pl. papillae) a short, nipple-like protuberance
.

Natural habitat

still or slowly moving saline, brackish or fresh water; marshes, along streams, mud flats

Additional comments

A genus of about 60 species, the most commonly encountered amphibiousamphibious:
(adj) of a plant able to live on land or in water
species being Cotula coronopifolia. There is only one obligately aquatic species, C. myriophylloides Harv., which has opposite-whorled leaves, divided into capillarycapillary:
(adj) slender, hair-like
segments.C. nigellifolia (DC.) K.Bremer & Humphries, a hydrophyte endemicendemic:
(adj) restricted to a certain geographical location
to South Africa, is toxic and affects the central nervous system in cattle, causing encephalitis. The following species are tenagophytes (juvenile stage submergedsubmerged:
(adj) (syn. submersed) under water; submerged below the water surface
or floating, adult stage terrestrialterrestrial:
(adj) growing on land as opposed to living in water
): C. vulgaris var. australasica J.H.Willis, C. paludosa Hilliard and C. filifolia Thunb.