Tag Archives: leaves

The Light Coming into the Greenhouse

Here’s a treat: These beautiful photos were taken in the Conservatory range last week by Noah Le Claire-Conway, PhD student in Plant Sciences. (Equipment: Nikon D2X camera with an AF Micro Nikkor 60 mm lens.)

jewel orchid

Jewel Orchid, Ludisia discolor

Brazilian Orchid, Epidendrum sp.

Brazilian Orchid, Epidendrum sp.

Watermilfoil, Myriophyllum aquaticum

Watermilfoil, Myriophyllum aquaticum


Aristocrat Plant, Haworthia coarctata

ice plant

Yellow Ice Plant, Delosperma nubigenum


Spoon-leaved Sundew, Drosera spatulata


Echeveria sp.

Papaya, Carica papaya

Papaya, Carica papaya



Featured Plant: Poinsettia

poinsettia display(So many questions about poinsettias at this time of year! Here’s a “Featured Plant” post about these lovely holiday plants, from 2012. See you in 2015!)

December 12th is officially Poinsettia Day! These beautiful plants that we associate with the Christmas season have a fascinating history. They are native to the warm climate of Southern Mexico. They are found in the wild in deciduous tropical forest at moderate elevations down the entire Pacific coast of Mexico from Sinaloa to Chiapas and into Guatemala. They are also found in the interior of Mexico in the hot, seasonally dry forests of Guerrero and Oxaca. Although they are Euphorbias (Spurge Family), and were originally named Euphorbia pulcherrima, they were renamed Poinsettia pulcherrima to honor Joel Roberts Poinsett.

joel-roberts-poinsettPoinsett was the first American ambassador to Mexico, and was very interested in botany. He often wandered the countryside looking for new and interesting plants. In 1828, as he was traveling through the Taxco region of the new Republic of Mexico, he saw a beautiful shrub with large red flowers and took cuttings, which he brought back to the greenhouse at his South Carolina home.

The modern American Poinsettia “industry” was created almost single-handedly by the Ecke family of California at the turn of the last century. This is a great American immigrant success story! From the website Poinsettiaday.com:

“Originally from Germany, Albert Ecke emigrated to the U.S, in 1906 and settled in the Hollywood area. The family lived off the land growing fruits and vegetables but were also, by 1909, selling cut Poinsettias at a stand on Sunset Boulevard. Poinsettias grew wild in the area and son Paul Ecke (Paul Sr.) had the idea that the ruby flowers would sell well around Christmas. This turned out to be so successful that in 1915 Albert Ecke bought five acres in nearby El Monte to grow poinsettias. By 1917 the Eckes were shipping plants to customers in New York and Chicago. When Albert died in 1919, Paul Sr. took over the flower business and though the family prospered, by 1923 the pressures of a rapidly urbanizing Hollywood led Paul Sr. to move the operation to 40 acres in Encinitas.

poinsettias in the field

Workers at the Ecke Ranch, Encinitas, California,1939

In 1955 Paul Ecke Jr. returned with a degree in floriculture from Ohio State with ideas of his own about how to move forward with the family business. It took some doing but eventually he as able to convince Paul Sr. to move the growing out of the fields and into greenhouses. Paul Jr and the Ecke family had a secret technique that caused every seedling to branch, resulting in a fuller plant. Paul Jr. also took a very active role in marketing poinsettias, making them visible on television programs such as The Tonight Show, the Dinah Shore Show, and  Bob Hope’s Christmas Special. He also had them displayed in women’s magazines like The Ladies Home Journal and Better Homes & Gardens. By the time of his death in 2002, poinsettias were the number one selling potted plant in America, in part to his tireless promotional efforts.

poinsettias in greenhouse

poinsettia mix

Here are a few more Poinsettia facts:

  • The Aztecs called them “Cuitlaxochitl”. Montezuma, the last Aztec emperor, had them brought by carts to adorn his city (what is now Mexico City).
  • What look like the petals of flowers on the Poinsettia are actually bracts (modified leaves) and the flowers are only the small yellow centers.
  • Poinsettias are NOT poisonous!
  • Poinsettias are the best selling potted plant in the United States and Canada and contribute over $250 million to the US economy at the retail level.

On a long-ago trip to San Francisco at New Years, I remember wandering through the back streets of that beautiful city and seeing Poinsettias growing as huge shrubs in tiny urban yards and gardens. It was the first time I had ever seen a tropical plant growing in an outdoor environment.

poinsettia growing outside

If you are interested in keeping your holiday poinsettia as a year round house plant and having it bloom again, the University of Illinois has a great website giving details of Poinsettia culture: The Poinsettia Pages.

Featured Plant: Welwitschia mirabilis


The Horridge Conservatory is fortunate to have a specimen of a weird and wonderful plant: Welwitschia. (Thank you, Arielle!) Mirabilis is the only species in the genus and Welwitschia is the only genus in the family Welwitschiaceae. It is native to the Namib Desert on the coast of the Atlantic Ocean in Namibia and Angola.

What makes it so unusual? An adult Welwitschia consists of only two leaves, a stem base and roots. Its two permanent leaves are the original leaves from when the plant was a seedling– they continue to grow and are never shed. Those two leaves grow from a basal meristem in the plant’s terminal groove. They eventually grow to a length of 2 – 4 meters and become split, frayed and shredded into several well-separated strap-shaped sections which lie on the ground. This gives the appearance in older plants of having many leaves, but there really are only two.

welwitschia mirabilis

The stem is low, woody, and obconical in shape. It grows to about 500 mm in height. There are separate male and female plants. Welwitschia produces cones but is not wind pollinated as most cone-bearing plants are. It is pollinated by flies, true bugs, and most commonly, the Welwitschia bug, Odontopus sexpunctatus.

welwitschia bug

Welwitschia is ecologically highly specialized, and is adapted to grow under arid conditions receiving regular fog. This regular, dense fog is formed when the cold north-flowing Benguela Current meets the hot air coming off the Namib Desert. The fog develops during the night and usually subsides by about 10 a.m The broad, downward drooping leaves collect condensation, which drips down onto the plant’s own root zone. It also has numerous stomata on both leaf surfaces and fog-water is taken up directly through these stomata. The fog has been estimated to contribute 50 mm in annual rainfall! A long taproot reaches deep for underground water in this part of the world which often receives less than100 mm of rain a year.

According to the Wikipedia article “Welwitschia”,

“Although Welwitschia mirabilis is not at present immediately threatened, there being abundant populations over a large area, its status is far from secure; its recruitment and growth rates are low, and its range, though wide, covers only a single compact, ecologically limited and vulnerable area.”

Welwitschia mirabilis in the Namib Desert.

It is interesting that it is possible, and not even terribly difficult, to grow Welwitschia as a house plant. A few Botanical Gardens (but not URI) offer seed for sale on line. The greatest danger to the germinating seeds is fungal infection. A very sandy soil mix helps reduce this risk. There is a great article on germinating and growing Welwitschia at home on the Planzafrica website, as well as information about the discovery of the plant by Friedrich Welwitsch.

Welwitschia mirabilis is thought to live 1,000 years or more!


Young Welwitschia mirabilis plant in the desert area of the Horridge Conservatory.

The Fifth Season

rose in november

It is indisputably late fall; almost the first day of winter. Or, as they say in Britain, Midwinter, which makes more sense, because as soon as December 21st rolls around, the days start getting longer…and isn’t winter the season of short days and long nights? (My husband insists the days keep getting shorter into January — “the lag time”.)

Right now it feels like some kind of fifth season is upon us. Most of the deciduous leaves are gone, blowing across bare yards and sidewalks. Muted colors fill garden and sky. The days are indeed short, making me want to hibernate. But wait…there are roses still blooming, and the air is warm enough for confused gnats and fruit flies to hatch. I leave my coat home, and wonder if I can still get the whole sunny border dug up and replanted before it gets “too cold” — whenever that may be. This strange fifth season made Thanksgiving a delight, and makes Christmas seem months away! I’m enjoying it all with a sense of dread that tomorrow or the next day will suddenly be freezing cold without any warning. Meanwhile, I continue transplanting, snipping fresh parsley and chives from the garden, and working without a hat or coat.

Has the climate changed? Eighteen years ago, in 1993, it began snowing the first week of December and there was snow on the ground until Easter. Happy Birthday, Philip!

As the color fades

turkish hazel bark


By now the colors are definitely more muted in the garden.  Some remains —  a few  trees hanging on to their yellow leaves, the calendulas  STILL blooming. Today what really began to stand out as I  prowled the garden with the camera, was texture and shape. (duh). I am so entranced with– intoxicated by– color through spring, summer, and fall, that I forget to look with a more discerning eye for the shapes of things.  The unbelievable variety in the shapes and textures of the leaves that are yet green, and those that are not. The bark —  rough, smooth, furrowed, flaking,peeling, cracking, in many subtle shades of browns and grays.  The difference in the way the top and undersides of the same leaf reflect the light. The difference in form of the trees. Some tall and narrow, some spreading; twiggy or sparse, some with buds for next year standing out against the sky, and some with buds hidden.

rhododendron leaves

Then standing back: the landscape itself. The lack of color  allows me to see the big picture. One of my favorite things about the Botanical Gardens is the stone walls. These were built in the 1940s by the Work Projects Administration during the Depression. They are beautiful and well made. The contrast of the stones with the plants is wonderful and the walls have great texture on their own. They create the “room” of the main garden where the stage is. A little bit of clearing this past year has made some sections more visible. My early spring photos always include the walls because the delicate new foliage and flowers against the rough and enduring stonework is an irresistible image. Now, in this more subtle  season, the walls add texture, shape, and a sense of permanence to the landscape.

WPA plaque