Download Aquatic Collection - Denver Botanic Gardens

AQUATIC COLLECTION
Prepared by Tamara Kilbane, Senior Horticulturalist of Aquatic Plants, October 2013
Description
The aquatic collection consists of the following sub-collections:
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Hardy water lilies
Tropical water lilies
Intersubgeneric water lilies
Historical water lilies (Denver Botanic Gardens’ Rocky Mountain Legacy Collection)
Lotus
Victoria water lilies
Tropical marginal plants
Hardy marginal plants
Floating plants
Carnivorous plants
History of the Collection
Since the summer of 1973, visitors to Denver Botanic Gardens have enjoyed an ingenuously designed waterway.
Throughout the gardens, the abundance of water allows for numerous grand opportunities to display a multitude of
exciting aquatic plants from as far north as Alaska to as far south as South America and Africa.
The world’s first water gardening society was founded on February 13, 1983, when the Colorado Water Gardening
Society (CWGS) was created in a Denver Botanic Gardens’ classroom. Soon after, the International Waterlily and
Water Gardening Society (IWGS) was created. Water gardening has grown at a rapid pace ever since, gaining an
enthusiastic following worldwide. Denver Botanic Gardens has remained a main force in this movement. The summer
displays at the Gardens, which include more than 500 plants, focus attention on the enduring power of water
gardens, especially in a steppe climate.
In 1987 and 1997 Denver Botanic Gardens and the Colorado Water Gardening Society hosted the International
Waterlily and Water Gardening Society Symposium and will host the conference again in August of 2014. The first
ever waterlily trials were hosted at Denver Botanic Gardens at the 1997 symposium and have been held at DBG in
2012 and 2013. They will continue to be held at the gardens in 2014. Water lilies that Denver Botanic Gardens
have named and helped introduce, Nymphaea ‘Colorado’ and N. ‘Joey Tomocik’, have received international
recognition for their excellence.
Collection Facts
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Ornamental water gardening dates back to the early botanical gardens in Europe when water lilies were added
to living encyclopedic collections.
Water gardening as a hobby is relatively new – hardly known 20-25 years ago.
Water gardening enthusiasm began in Denver with the formation of the Colorado Water Garden Society in
1983.
The International Waterlily and Water Gardening Society was founded in 1985.
The water gardens at Denver Botanic Gardens are maintained year-round by DBG staff and volunteers from the
Colorado Water Garden Society who contribute 1,400 hours each year to the Gardens.
Six to eight cultivars have been named by Denver Botanic Gardens.
These materials are for Denver Botanic Gardens use only.
AQUATIC COLLECTION
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DENVER BOTANIC GARDENS WATER FEATURES SYSTEM
The beginning of our water system starts at the 4 towers fountain (west side of Anna’s Overlook). Water flows north
through the small opening on the northwest side of Anna’s Overlook (future Science Pyramid) and continues down to
Gates Montane Garden.
The Monet pool and the plants displayed on it were designed and chosen to resemble that of Claude Monet’s (1840
- 1926) at his home in Giverny, France. Monet was a great gardener, as well as a leader of the Impressionist
Movement and spent the last 20 years of his life painting the water lilies in his garden. He especially liked to focus on
how water, light and color interplayed.
The Japanese Garden and Gates Montane Garden ponds mark the end of the circulating water system. Water
empties out here and is pumped back to the beginning. These ponds hold water year-round.
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The water is continuously circulating and takes approximately 1½-2 hours to make a complete journey.
The system holds/uses about 394,000 gallons of water.
Pools are 18 inches deep and are lined with concrete.
Water is replenished in a couple of places along the route.
Water is colored using black colorant applied weekly so that you can’t see the bottom or pots. It also provides a
good reflection for pictures.
Algae are controlled by hand with use of a multi-strain bacteria applied weekly.
Mosquitoes are controlled by the use of mosquito dunks, a non-chemical pesticide.
4 pools are not connected on the water system: the Romantic Gardens pool, Birds & Bees pond, El Pomar
waterway, and the Rock Alpine Garden.
These materials are for Denver Botanic Gardens use only.
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SIGNATURE PLANTS OF THE AQUATIC COLLECTION
Hardy water lilies, Nymphaea spp. and Hybrids
Family: Nymphaeaceae (Waterlily)
Native Range: Worldwide, varies by species
Leaves have smooth margins and rest on the water.
Flower color is primarily white and yellow, though pastel pinks also occur. Colors are less intense than in the
tropical species.
Flowering begins in May if weather is warm enough and continues well into September. July and August are peak
months.
Easy to grow and hard to kill.
Colorado’s climate is excellent for hardy water lilies because they benefit from the long dormant period during the
winter.
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Tropical water lilies, Nymphaea spp. and Hybrids
Family: Nymphaeaceae (Waterlily)
Native Range: Tropical still waters worldwide
Leaves rest on the water and have serrated or ruffled margins; leaves are often a reddish color.
Fragrant flowers begin blooming in July and continue into October. Blooms are intense in color and can be blue or
purple, and are held high out of the water.
Can withstand the heat and actually require at least four hours of direct sunlight each day for good color and
growth. Also requires still water.
Largest are star lilies. Purple star lily comes higher out of the water (16") than any other tropical waterlily.
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Marginal Plants
Marginal plants grow in shallow water edges of ponds, lakes, streams, marshes and swamps. They exist at the margin
of land and water.
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Roots are submersed in the mucky soil located beneath the water.
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They typically do not survive in deep water but prefer water that is 6 inches or less.
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Marginal plants are ecologically important as they are a natural part of ecosystem life cycles.
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As the leaves, stems, flowers and seeds die, they fall into the water and fill it in, creating land. The marginal plants
gradually move further toward the center of the body of water into the new shallow water. As a result, the water is
eventually filled in with land. Finally, if left alone, no water exists and the marginal plants die out because their
needs are no longer fulfilled.
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Marginal plants have roots in the soil helping to hold it in place and reduce soil erosion from water runoff into the
body of water.
Some types of marginal plants:
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Acorus calamus, sweetflag
Spartina pectinata, prairie cordgrass
Iris pseudacorus, yellow water iris
Thalia dealbata, hardy canna
Typha spp., Cattails
These materials are for Denver Botanic Gardens use only.
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SOME PLANTS TO HIGHLIGHT
Nymphaea ‘Denver’s Delight’
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Hardy water lily
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One of the first water lilies to bloom in the spring
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Found in Berkeley Lake (I-70 and Sheridan) and believed to have occurred
there since the 1940s. It was collected and grown successfully.
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An auction for naming it was won by Carol Purdy on February 20, 2004.
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Can be found in the Romantic Gardens pool
Interesting Notes
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The Romantic Gardens pool features the Rocky Mountain Legacy Collection (RMLC), which is comprised of several
unique water lilies trialed at the gardens. Many were named by former curator of aquatic plants, Joe Tomocik. The
designs change yearly and during the course of the year.
Easy tips for identifying different types of water lilies:
Huge floating platter-like leaves = Victoria waterlily
Leaves at water level = water lilies
(smooth leaf margins = hardy, serrated leaf margins = tropical)
Large rounded leaves and blooms high out of the water = lotus
Blue Egyptian Lotus
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Scientific name: Nymphaea caerulea
Family: Nymphaeaceae (Waterlily)
Tropical water lily
Easily grown from seed and tolerant of cold water.
Frequently depicted in Egyptian art
Used to make blue lotus tea, wine and martinis
Nymphaea caerulea – Blue
Egyptian Lotus. SSR Botanical
Garden, Mauritius. Wikimedia
Commons – Author:
PalmBeaches974
These materials are for Denver Botanic Gardens use only.
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Victoria Water Lily
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Scientific name: Victoria cruziana and Victoria ‘Longwood Hybrid’
Family: Nymphaeaceae (Waterlily)
Native Range: Amazon River
Large plant that likes slow moving water
Seeds in January
Plants are grown from seeds then planted in gardens, with peak flowering in
August or September.
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Leaf pads:
Leaf pads can get up to 50 inches wide.
Pads can expand as much as 8 inches in a single day with the raised edge varying from 1-6” in height.
Pads can hold enough weight to allow birds to nest upon them. Strong hollow veins support the leaf and sharp
thorns cover the ribs densely to protect the leaf covering and flowers from being eaten.
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Flowers:
Bloom at night in late August and September, lasting only 48 hours.
They emerge from a tennis-ball-sized bud as a creamy white female flower. Upon first opening, the flower
temperature rises 20° F, dispersing its pineapple fragrance a distance of 20-30 feet.
Scarab beetles are attracted to the scent of the flowers where they receive a meal and a warm home inside
the bloom which closes over them. The next night, the flower opens as a reddish-purple male flower and the
beetles leave, picking up pollen to deposit in another first-night female white flower.
Interesting Notes
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Victoria water lilies were officially described in 1837. It wasn’t until 1849 that Kew Gardens was able to grow
some (keeping seed/plant alive was the challenge). The first flowers on this continent came to Philadelphia in
1951.
Structural principles found on the underside of Victoria pads were used to design the Lily House at Chatsworth.
This was the first building to employ a rigid, self-supporting ribbed structure to hold glass panes. It was an ancestor
of modern greenhouses and steel-and-glass skyscrapers. The same principals were used in 1851 to engineer the
Crystal Palace for Queen Victoria and Prince Albert. This structure contained a pool exhibiting Victoria waterlilies.
These materials are for Denver Botanic Gardens use only.
AQUATIC COLLECTION
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Lotus
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Scientific name: Nelumbo spp.
Family: Nelumbonaceae (Lotus-Lily)
Native Range: Asia, Australia, North America
Naturally prefer muddy waters of lakes and streams.
Plants have huge aerial or surface leaves that are waterproof.
Fragrant blooms reach high out of the water.
Flowers are 2-12 inches in size, last three days and are typically yellow, white or
pink. They begin blooming around July 4th, which is between the bloom time of hardy
and tropical water lilies.
Seed pods are popular for use in flower arrangements.
In Asia food is rolled in the leaves and steamed; petioles pickled or used with the flower petals in salads; seeds
shelled and eaten like peanuts; the tuber is a component in many dishes.
Lotus has been revered in many cultures for centuries and often symbolizes longevity.
Seeds have been found still viable in Egyptian tombs after thousands of years from the time they were deposited.
Papyrus or Egyptian Paper Reed, Cyperus papyrus
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Family: Cyperaceae (Sedge)
Native Range: Southern and Eastern Africa, Arabia; (introduced; Fla.)
Grows well in riverbanks and wet regions up to 3 feet deep. Can grow in a pond
or as a house plant.
6-10 feet in height, topped with a bushy cluster of fine green thread-like strands
with small flowers at their ends.
Triangular stems (sedges) may be 15 cm thick.
Roots are a source of food, medicine and perfume; stems are used to make
baskets, floor mats, ropes, clothing, footwear, boats, assorted building materials
and writing material.
www.jadu.de
Oldest known papyrus document dated to 2,600 B.C.
Rice and papyrus farming represent forms of ancient agronomic water gardening techniques.
Interesting Notes
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Plant in 2-20 gallon containers filled with rich, fertile soil and set in 1-6 inches of water.
Protect from wind; may need staking.
Winter indoors in a sunny, humid location. Set the plants in a deep dish of water that covers the bottom half of the
pot.
Return outside when night temperatures reach 60°F.
These materials are for Denver Botanic Gardens use only.
AQUATIC COLLECTION
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Umbrella Palm
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Scientific name: Cyperus alternifolius
Family: Cyperaceae (Sedge)
Native Range: Madagascar
Requires wet conditions and rich peaty soil in tropical areas.
Thin leaves radiating from the top of long stems, browning flowers in the center of
the leaves.
Related to papyrus of Nile.
Will make a good house plant if it never dries out – the wetter the roots are, the
more it thrives.
Interesting Notes
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Cyperus alternifolius –
Umbrella Plant
Fertilize monthly during growing season with a balanced fertilizer diluted to ½
the strength recommended on the label.
The best soil mixtures is two parts peat moss to one part loam to one part sand.
Take cuttings from top 4 - 6 inches of the plant and place them upside down in water. When new plants emerge,
repot in soil.
Can also divide the plant and keep the younger growth from the outside edges of the pot and discard the old
growth in the center of the pot.
Pitcher Plants
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Scientific name: Sarracenia sp.
Family: Sarraceniaceae (Pitcher Plant)
Native Range: SE United States
Carnivorous plant
Found in various parts of the Gardens
Prefers bogs, savannahs and flat woods at wettest parts. Adapted to poor soils.
Leaves are evergreen, modified into pitchers and arranged in a rosette. Leaves curl
around and fuse to form a liquid-holding vessel.
Flowers are solitary, rose pink to dark red, on a leafless stem rising from the
rhizome.
Propagated by seed or dividing the rhizomes. Rhizomes may live 20-30 years
Sarracenia ‘Dixie
under the soil.
Lace' – Pitcher Plant
Red color and nectar attracts insects which follow red veins downward. The tube is
lined with fine hairs, all pointing downward. An insect falls into the pitcher which usually is filled with water and
contains a digestive enzyme that soon dissolves the insect.
Collection of wild pitcher plants for sale has resulted in localized extinction in some areas.
Other species of pitcher plants include Cephalotus spp. and Nepenthes spp.
These materials are for Denver Botanic Gardens use only.
AQUATIC COLLECTION
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Venus Flytrap
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Scientific name: Dionaea muscipula
Family: Droseraceae (Sundew)
Native Range: United States (Coastal N. & S. Carolina, in bogs &
pine barrens)
Carnivorous plant
Found in various parts of the Gardens
Flowers are white.
One plant has about 6 traps that can get up to 3 inches wide.
The traps are actually two leaves that look like an open clamshell and
have edges lined with spines.
Trigger hairs are arranged in a triangular pattern inside the trap.
Reddish color and sweet nectar inside attracts insects.
As the insect feeds on the nectar it brushes past the trigger hairs and the trap closes.
A trap can close only three or four times before it dies. The trap has two ways of ensuring it has a good meal and
does not waste its energy closing empty:
1) The nectar is far enough from the trigger hairs so smaller insects cannot touch them. A small insect is not
enough food for the plant.
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2) The trap won’t close unless two different trigger hairs are touched or one hair is touched twice.
The trap closes only slightly at first, keeping larger insects in and allowing smaller insects to sneak out.
If no insects remain, inside the trap re-opens within 24 hours.
After catching a larger insect, the trap closes tightly and releases fluids that drown the insect. It then digests the
insect over several days eventually re-opening and exposing the undigested insect parts.
Other types of carnivorous plants: Butterworts, Sundews, Byblis, Cobra Lily, Genlisea, Bladderworts, Waterwheel
plant.
These materials are for Denver Botanic Gardens use only.
AQUATIC COLLECTION
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