Alisma subcordatum

Alisma subcordatum (15/08/2015, Kew Gardens, London)

Position: Full sun

Flowering period: Summer to early autumn

Soil: Wet, poorly drained (water depth of up to 30cm)

Eventual Height: 1m

Eventual Spread: 50cm

Hardiness: 4a, 4b, 5a, 5b, 6a, 6b, 7a, 7b, 8a, 8b, 9a

Family: Alismataceae

Alisma subcordatum is a deciduous, perennial marginal aquatic with a clump form habit. Its mid to dark green leaves are ovate to elliptic with sinuate margins, up to 15 cm long and 10cm broad. Its flowers have yellow stamen, three pale pink or white petals and are up to 1cm across. The flowers appear in panicles on an erect upright, branched stem above the leaves. Its fruit is an ovoid achene and up to 3mm long. Its roots are rhizomes.

Alisma subcordatum Flower (15/08/2015, Kew Gardens, London)

Alisma subcordatum, commonly known as the American Water-plantain, Southern Water-plantain or Mad-dog Weed, is native to North America. In its native habitat it grows in shallow water at the margins of bodies of fresh water and ditches. Alisma subcordatum is synonymous with Alisma parviflora and Alisma plantago-aquatica var. parviflorum.

The etymological root of the binomial name Alisma is derived from the Celtic alis meaning ‘water’. Subcordatum is derived from the Latin sub meaning ‘below’ and cordata meaning ‘heart shaped’.

Alisma subcordatum Leaf (15/08/2015, Kew Gardens, London)

The landscape architect may find Alisma subcordatum useful as an aquatic plant for plating at pond and lake margins. It is also very useful for ditch planting as it tolerates fluctuating water levels, this also makes it ideal for use in SUDS (Sustainable Urban Drainage System) planting scheme.

Ecologically, Alisma subcordatum flowers are attractive to pollinating insects, including some species of flies, bees and beetles.

Alisma subcordatum prefers wet, poorly drained soils. It prefers a water planting depth of between 0cm to 30cm below water level. It tolerates most pH of soil.

Alisma subcordatum requires little maintenance. Large clumps may be divided in spring.

Landscape Architecture

Typha laxmannii

Typha laxmannii (15/08/15, Kew Gardens, London)

Position: Full sun to partial shade

Flowering period: Mid summer to late autumn

Soil: Wet (planting depth 0cm to 150cm)

Eventual Height: 1.3m

Eventual Spread: 90cm

Hardiness: 3a, 3b, 4a, 4b, 5a, 5b, 6a, 6b, 7a, 7b, 8a, 8b 9a, 9b, 10a, 10b

Family: Typhaceae

Typha laxmannii is a deciduous, marginal, perennial, freshwater wetland plant with an arching habit. Its light green leaves are upright, strap shaped, are up to 4mm wide and 90cm long. Its brown flowers are monoecious with the female being distinctly separated from the male; female are cylindrical to ovoid, up to 30cm long and borne below the male on long flower stalks. The male which are slender and up to 1.5mm wide whither away once divested of pollen. Its fruit are borne densely upon the pistillate section. the roots of this plant are rhizomatous, which aids its spread.

Typha laxmannii Fruit (15/08/15, Kew Gardens, London)

Typha laxmannii, commonly known as Graceful Cattail or Narrow leaved European Cattail, is native to south west Asia and Europe. In its native habitat it grows in lakes, ponds, channels, swamps and shallow rivers.

The etymological root of the binomial name Typha is derived from the Greek name for this plant, ‘Tufh’. Laxmannii is named for Erik Gustavovich Laxmann (1737 – 1796), a Finnish clergyman, scientist and explorer.

The landscape architect may find Typha laxmannii useful for pond, streams and lake planting. This plant is suitable for use as part of a Sustainable Urban Drainage Systems (SUDS). It may used for planting in drainage ditches, swales and balancing ponds. It should be noted this species of Typha can be invasive, spreading by rhizomes.

Typha laxmannii Leaf (15/08/15, Kew Gardens, London)

Ecologically, Typha laxmannii provides food and nesting sites for waterfowl, marsh birds and small mammals.

Typha laxmannii prefers wet, fertile soils. It tolerates most pH of soil. It should be planted in water to a depth of 0cm to 150cm.

Typha laxmannii requires little maintenance. Large clumps may be divided in spring. Unwanted plants may be removed either mechanically or by the use of appropriate herbicide. Structures may be installed to prevent its unwanted spread.

Landscape Architecture

Schoenoplectus tabernaemontani

Schoenoplectus tabernaemontani (15/08/15, Kew Gardens, London)

Position: Full sun to light shade

Flowering period: Summer

Soil: Poorly drained/ wet (to 30cm water depth)

Eventual Height: 3m

Eventual Spread: 1m

Hardiness: 3a, 3b, 4a, 4b, 5a, 5b, 6a, 6b, 7a, 7b, 8a, 8b, 9a, 9b

Family: Cyperaceae

Schoenoplectus tabernaemontani is an evergreen, grass like water perennial with a clump forming tufted habit. Its blue/ green leaves are round in cross section, up to 3m long and 16mm across. The upper part of the leaf may produce a short blade. Its small brown flowers appear at the ends of the leaf stems as a terminal head of several branches  consisting of many compact clusters of egg shaped spikelets. Its roots are rhizomes from which this plant spreads.

Schoenoplectus tabernaemontani, commonly known as Great Bulrush, Grey Club Rush or Soft Stem Bulrush, is native to most temperate regions of the northern hemisphere including the UK. In its natural habitat it occurs in dune slacks, tidal channels and slow moving brackish waters on the coast. Inland it is found in slow moving rivers, bogs, wet, pasture, shallow pond margins and it occurs in stands.

Schoenoplectus tabernaemontani Leaf (15/08/15, Kew Gardens, London)

The etymological root of the binomial name Schoenoplectus is derived from the Greek schoinos meaning ‘rush’ and plektos meaning ‘twisted’. Tabernaemontani is named for Jacobus Theodorus (1525 – 1590), called Tabernaemontanus, a German physician and Botanist.

The landscape architect may find Schoenoplectus tabernaemontani useful for UK native wetland planting schemes, at the edges of lakes, ponds or slow moving rivers. It is also useful for brackish and coastal conditions.

Ecologically, Schoenoplectus tabernaemontani is valuable along fresh and salt water shorelines helping to buffer against water erosion.

Schoenoplectus tabernaemontani prefers wet, poorly drained, fertile soils. It tolerates most pH of soil. It will tolerate a water depth to 30cm. It is salt tolerant.

Schoenoplectus tabernaemontani requires little maintenance.



Landscape Architecture