A garden oasis and cultural center overlooking the Hudson River

Plant of the Week: Aloe greatheadii var. davyana (Spotted Aloe)

Charles Day is Wave Hill’s Ruth Rea Howell Senior Horticultural Interpreter.

South Africa has a wide range of climates and a variety of plant habitats. The Western Cape, for example, is noted for its hot, dry summers and mild, moist winters. Other regions, including the grasslands of the high veld, experience cool, very dry winters and warm, periodically wet, summers.

This climatic variation explains the differences in the growth cycles of South African plants. Those that have to endure the summer droughts of the Cape are active in the winter months but go completely dormant in the summer. Plants that make their home on the veld, such as this spotted aloe (Aloe greatheadii var. davyana), are dormant during the dry winters and do all their growing in the summers.

Towards the end of winter dormancy, however, the spotted aloe (and many of its kin), will flower even when the landscape is still parched. Despite showing signs of drought-stress—with dried and shriveled leaf-tips—it is still capable of producing healthy spikes of yellow-orange blooms that stand up tall and obvious in the tinder-dry landscape.shrivelled-tips-2

This seemingly odd behavior ensures that the flowers get the undivided attention of any native pollinating bees and birds in the area, thus increasing the chance of successful seed production.

Our own plant in the Cactus and Succulent House, the right-hand wing of the Marco Polo Stufano Conservatory, has three, fine, flower spikes this year and is surrounded by other aloes that are also starting to bloom.the-plant

the-settingA note for the truly botanically interested: Aloe greatheadii var. davyana was formerly known as A. verdoorniae, and some taxonomists now recognize it as A. davyana.

Plant of the Week: Crocus tommasinianus

Horticultural Interpreter Alison Filosa works with Charles Day and the rest of Wave Hill’s Public Programs Department.

Crocus tommasinianus is otherwise known as snow crocus as it is one of the first crocuses to bloom.the-close-up

Originally found on the hillsides of Hungary, this small, dainty, purple crocus sticks its head up before the last snowstorm in March. It usually blooms in late winter to early spring and grows to 4 inches tall.the-plant

This early spring, two nor’easters have occurred as the crocus have emerged from the ground here at Wave Hill. Together with Eranthis hyemalis (winter aconite) and the Adonis amurensis (Adonis/pheasant’s-eye), it’s the first—and very welcome—sign of spring. Look for it along the path to the Wild Garden and in the Wild Garden itself.the-setting

The specific epithet name of Crocus tommasinianus honors Muzo Guiseppe Spirito de Tommasini (1794–1879), a botanist from Trieste.

Plant of the Week: Pelargonium crithmifolium (Samphire-leaved Pelargonium)

Charles Day is Wave Hill’s Ruth Rea Howell Senior Horticultural Interpreter.

Pelargoniums—familiarly called “geraniums”—come in many shapes and sizes. Almost all are native to Southern Africa and some of them come from surprisingly dry habitats.

The sturdy-looking, samphire-leaved pelargonium (Pelargonium crithmifolium) is one of the largest of all pelargoniums. It can grow to nearly four feet high, and is very well adapted to the conditions of its homelands in the Northern and Western Cape of South Africa.the-plant

It has thick, succulent stems and a drought-deciduous habit, both features that enable survival during hot and dry summers. By shedding its leaves before the onset of drought, moisture loss is kept to a minimum and the thickened stems function as water-storage devices.the-stem

Although devoid of foliage during its dormant period, it is able to continue photosynthesis thanks to the presence of chlorophyll in its green-tinged bark.

The mild winters bring rain and the possibility of growth. New leaves unfurl in late autumn and flowers appear by early spring—as can be seen this week in the Cactus and Succulent House, the left-hand wing of the Marco Polo Stufano Conservatory.close-up

If this piques your interest, plan to visit on Scented Geranium Day, Sunday, July 8. We’ll be looking at the astounding varieties and fragrances of Pelargonium species and hybrids in Wave Hill’s gardens, learning how to cook with geraniums and making soap using geranium oil.

Plant of the Week: Draba sp. (Whitlow Grass species)

Charles Day is Wave Hill’s Ruth Rea Howell Senior Horticultural Interpreter.

This little, yellow-flowered, whitlow grass (Draba sp.) in Wave Hill’s T. H. Everett Alpine House was grown from seed exactly a year ago. It appeared among a batch of gentian seedlings and was spotted by one of our sharp-eyed gardeners.the-setting

Once separated from its foster-family siblings, it was given individual attention and has now rewarded us by blooming profusely this spring.the-plant

close-upDespite the misleading common name, whitlow grass is not a grass but, in fact, a member of the mustard and cabbage family (Brassicaceae). There are more than 300 species of whitlow grass, most of them found growing wild in the mountains of North America, North Africa, Europe and Southwest Asia.

In medieval times, certain plants of this genus were used in the treatment of whitlows—painful inflammations on fingertips and toes.

Plant of the Week: Crassula rupestris (Concertina Plant)

Charles Day is Wave Hill’s Ruth Rea Howell Senior Horticultural Interpreter.

This week, our little concertina plant (Crassula rupestris) is putting on its annual display of neatly clustered pink flowers in the Cactus and Succulent House, the right-hand wing of the Marco Polo Stufano Conservatory.the-setting

close-upFound in the wild in some of the drier parts of South Africa and Namibia, it grows naturally in rocky places—rupestris indicates this affinity for rocks—and has several tricks to enable it to survive and spread in its arid environment. A slow-growing habit means that it requires less water than a more vigorous plant, and its thick, succulent leaves are able to retain moisture during prolonged droughts.leaves

Flowering is followed by the release of masses of tiny, dust-like seeds. In the wild, the lightest gust of wind would scatter them across the parched landscape. A small number might happen to lodge themselves in a crevice where water lingers following night dews or the occasional rain shower. If they are lucky, this might be enough to allow for germination and growth.

The genus Crassula contains hundreds of species from many parts of the world. All are succulents, but it is mainly the species from Southern Africa which are the most interesting for ornamental use. The name comes from the Latin Crassus, meaning solid or thick, alluding to their fleshy foliage.

Plant of the Week: Aeonium arboreum ‘Atropurpureum’ (Purple Tree Aeoneum)

Charles Day is Wave Hill’s Ruth Rea Howell Senior Horticultural Interpreter.

Blooming now in our Cactus and Succulent House—the right-hand wing on the Marco Polo Stufano Conservatory— is the purple form of the tree aeoneum (Aeonium arboreum ‘Atropurpureum’). It stands taller than most of the plants around it and is hard to miss—the flower spikes are large and very yellow.the-setting-2

The tree aeonium is native to Gran Canaria (one of the Canary Isles) where, despite the long dry summers there, it remains green and fresh-looking, even when neighboring plants might have turned brown or lost their foliage in an effort to conserve moisture. The genus name Aeonium comes from the Greek word aionios (eternity), not through any expectation that the plant will live forever, but because of this evergreen habit.close-up-2

Our purple form (‘Atropurpureum’) has dark-red, shiny leaves and these provide a striking contrast to the tight, conical clusters of yellow flowers.close-up-1

The branches of the plant that produce a flower stalk this year will die back in the coming weeks, leaving only the more youthful branches, which will continue to grow for future years.

Plant of the Week: Holmskioldia sanguinea ‘Bronze’ (Parasol Flower cultivar)

Charles Day is Wave Hill’s Ruth Rea Howell Senior Horticultural Interpreter.

This plant goes by several common names—parasol flower, Chinese hat plant, cup-and-saucer flower—all them alluding to the strange shape of its flowers. A narrow trumpet, formed by the tightly arranged petals, is backed by a wide, circular disk of fused sepals (the scales which covered the flower bud before it opened). This structure is called a calyx.close-up

Native to the tropical foothills of the Himalayas, it is a woody shrub with a semi-climbing habit and capable of growing to a height of ten feet. It can be kept much smaller when constrained in a flower pot, as can be seen in our Palm House, the central section of the Marco Stufano Conservatory.the-plant-and-the-setting

The normal flower color is bright red—hence the specific epithet of sanguinea (“color of blood”)—but this cultivar, Holmskioldia sanguinea ‘Bronze’, has pinkish-orange-colored flowers. The genus is named for the eighteenth-century Danish botanist Johan Theodor Holmskiold.

Plant of the Week: Galanthus elwesii (Greater Snowdrop)

Charles Day is Wave Hill’s Ruth Rea Howell Senior Horticultural Interpreter.

Snowdrops are a welcome sight in late winter. Their snowy-white blooms often appear in milder spells in early February. Even during colder conditions they will still develop and are almost always in flower by the end of the month. Many species of snowdrop exist, some of them distinguishable only by an expert. They are all native to Europe and the southwest of Asia, but have been cultivated in gardens in almost all the temperate parts of the world.close-up

The species we have most of at Wave Hill is the greater snowdrop (Galanthus elwesii). It is larger and more robust than many of the others, with a natural range that extends from parts of Greece and Bulgaria to western Turkey. Some are just starting to flower in a few sheltered spots in the Wild Garden and on the slope just to the south of Glyndor Gallery. More will appear over the next few weeks.setting

The genus name, Galanthus, translates from the Ancient Greek as “milk flower.” The specific epithet of this species, elwesii, honors botanist Henry John Elwes. Someone who maintains a collection of snowdrop species is called a galanthophile.

Plant of the Week: Acacia baileyana var. purpurea – Cootamundra Wattle (Purple Form)

Alison Filosa joined Wave Hill in late fall 2017 as Horticultural Interpreter. A former John Nally Intern at Wave Hill, she has experience in both private and public horticulture, including the Queens Botanical Garden, Brooklyn Bridge Park and the High Line.  She works with Charles Day and the rest of Wave Hill’s Public Programs Department.

Named after the Australian botanist Frederick Manson Bailey, who discovered many species in Australia, Acacia baileyana var. purpurea is a small evergreen tree with foliage that in the rigorous Australian climate would have a purple sheen that it loses as it ages. In the milder conditions of Wave Hill’s Conservatory, its foliage is blue-green, turning more gray with age.the-plant

Crowded on the stem, the leaves are feathery and bi-pinnate, meaning twice-divided. The Acacia is in the Fabaceae family, a relative of the pea. The name Acacia comes either from the Greek word akazo meaning “to sharpen,” or from the Egyptian word akakia for the Egyptian thorn (Acacia arabica).close-up

Its common name, the Cootamundra wattle tree, refers to the town in New South Wales in which it resides. It’s called ‘wattle’ since early Australians wove its thin branches and trunk with mud and clay in the construction of their homes, a method know in Europe as wattle and daub.

The brilliant-yellow, pom-pom flowers of our Acacia baileyana are slightly fragrant and make this tree a showstopper right through to early spring! See it in the Palm House, the central section of the Marco Polo Stufano Conservatory.setting

Plant of the Week: Ilex ‘Nellie R. Stevens’ (Holly cultivar)

Charles Day is Wave Hill’s Ruth Rea Howell Senior Horticultural Interpreter.

With her lustrous leaves and plentiful crop of bright red berries, our Nellie R. Stevens holly looks very handsome this winter.leaves-and-berries

berries-close-upShe stands proudly beside the Kerlin Overlook.setting-overlook-2

setting-with-riverMany broadleaved evergreens can suffer foliage damage in a bad winter. The leaves can take on a dried appearance—not surprising, since this damage is caused by lack of moisture. Green leaves will photosynthesize whenever the sun is shining, and photosynthesis requires water. When the ground is frozen, no more water is available to the tree. Strong sunlight and drying winds all add to this problem.

Fortunately, many hollies, like this one, have a waxy coating on their leaves and this helps to retain enough moisture to keep them looking healthy in all but the worst conditions.