Family - Plantaginaceae
Plantain Family - Alismataceae
has broad oval to elliptical leaves narrowed into
long stalks (as long as the leaf blades). The inflorescence is
about as long as the
leaves (10-15 cm, 4 - 6 inches).
has narrower (lanceolate)
leaves than Plantago
and shorter flower spikes.
The flower spikes are also a darker colour. Although
thought to be wind-pollinated it has recently been
observed that honeybees frequent the flowers.
inflorescence springs from a rosette of leaves and bears many
flowers clustered together in a spike.
The flowers develop first at the base of the spike and the female
parts mature before the male parts
(protogyny). The whorl of white
hairlike tufts seen protruding in the specimen above are the
anthers of the
mature male flowers. This separation in time, between the
development of the female and male organs helps
promote cross-pollination. Even though plantains may exhibit
genetic self-incompatibility (meaning that its
own pollen grains will not germinate when in contact with the
female stigmas of the same plant, protogyny
reduces pollen-pistil interference which occurs when the plant's
own (incompatible) pollen clogs the stigmas,
reducing the likelihood that pollen from another plant will
attach. (The pistil is the female part of the flower,
comprising one or more carpels that may be fused together).
Plantains are monocotyledons and mostly
the fruit of the water plantain, Alisma
This plant was so-named
because of the resemblance of its leaves to those of Plantago, but actually belongs to
different family of monocots. It grows in mud by ponds and
slow-moving rivers. The flowers are
borne on pyramidal inflorescences, each at the end of a long stalk
and each flower is up to 1 cm
across and has three lilac to white petals. Another species occurs
in the same habitat: Alisma
which has narrower (more lanceolate) leaves with less rounded,
(cuneate) leaf bases. However, leaf shape is highly variable and
overlaps between the two
species, such that the only reliable form of classification is to
look at the carpels or fruit
(achenes). In Alisma
the single style is at the top of the ovary, but off to one
side. It maintains this lateral position as the ovary expands and
develops into the achene. In
the style begins at the apex of the ovary, in a much more central
However, as the achene develops it swells over and the top
over-arches the style which gets
displaced more laterally. In mature A.
the style may be anchored slightly more
towards the apex of the achene, but there is considerable
variation. For definite identification the
young carpels have to be examined, with several being examined
from each plant.
and below: achenes from Alisma
showing the remains of the style
attached laterally. Mature achenes of Alisma
may be similar, though there is a
tendency for the style to be slightly more towards the top (more
apical) though this depends on
maturity. In Alisma
a more distinctive keel may reveal the more lateral original
position of the style in the achene.
the differences in the developing carpels becomes readily
apparent. A: Alisma
immature carpel; B: Alisma
carpel beginning to
develop; C: Alisma
further complicate taxonomy a hybrid form between A. plantago-aquatica and A.
called Alisma x rhicnocarpum. The leaf shape is
intermediate in these
forms and so more like a rectangle with rounded corners in
contour. However, this is
perhaps more easily identified by the fact that it is almost
entirely sterile with only one or
two achenes developing in each flower (are these sterile?). It
will thus usually be found
in the vicinity of both parents.
lateral positions of the style remains.
9 Sep 2018
17 Sep 2018
29 Sep 2018
has a basal rosette of elliptical
to diamond-shaped leaves with 5 to 9 prominent veins and
short stalks. The inflorescence stalk is unfurrowed and the
white flowers have pinkish stamens with purple filaments.
Unusually for plantains the Hoary Plantain is insect-pollinated.
Found on calcareous grassland.
and below: Buck's-horn Plantain (Plantago
growing on a sea-wall. The
brownish flowers have yellow stamens. The leaves are pinnatifid (deeply divided) and