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Costus malortieanus H. Wendl.
| Family Name: | Costaceae |
| Synonyms: | Costus elegans Petersen |
| Common Name: | Stepladder Ginger, Spiral Ginger, Spiral Flag |
The Stepladder Ginger is a fairly uncommon spiral ginger that produces conspicuous flowers with a yellow lip and two flashy striped corolla lobes. Its leaves are velvety to touch, with a faint dark-green banding, and situated closer to the tips, resembling a parasol.
Name
Classifications and Characteristics
| Plant Division | Angiosperms (Flowering Seed Plants) (Monocotyledon) |
|---|---|
| Plant Growth Form | Herbaceous Plant |
| Lifespan (in Singapore) | Perennial |
| Mode of Nutrition | Autotrophic |
Biogeography
| Native Distribution | Nicaragua, Costa Rica |
|---|---|
| Native Habitat | Terrestrial (Primary Rainforest) |
| Preferred Climate Zone | Tropical |
| Local Conservation Status | Non-native (Horticultural / Cultivated Only) |
Description and Ethnobotany
| Growth Form | It is a herbaceous, rhizomatous plant that grows up to 1 m tall. |
|---|---|
| Foliage | Leaves are obovate to elliptic, up to 35 cm long and 18 cm wide, covered in a dense layer of soft hair on both sides, and with a sunken midrib. Upper surface of the leaf is light green with faint dark-green bands, and lower surface is glaucous. Leaves are clustered towards the end of the green shoot in a spiral arrangement, like a parasol. Leaf bases have a closed sheath with a minuscule ligule (projection at the top of the leaf sheath), barely 1 mm long. |
| Stems | It has an underground rhizome (thick, horizontal modified stems) that produces green aboveground stems at regular intervals. |
| Flowers | Its inflorescence is globose to cylindrical, up to 9 cm long. Bracts are green, tightly pressed against one another. Bracteoles are present but hidden by the bract. Flowers are bilateral and tubular with yellow to cream/off-white calyx, a yellow lip, and flashy lateral lobes heavily marked with reddish-brown to brown stripes. |
| Fruit | Its fruit is an ellipsoid capsule (a type of dry, dehiscent fruit). |
| Habitat | It grows along rivers in rainforests at 30 - 100 m above sea level. |
| Similar | C. malortieanus vegetatively resembles C. osae but can be differentiated by the faint dark-green banding on the leaves, green globular inflorescence, showy flowers marked with yellow and brown stripes, and a minuscule ligule (projection at the top of the leaf sheath). |
| Cultivation | It grows well in fertile, well-draining soil and semi-shaded conditions. Avoid exposing in the hot afternoon sun. If the soil is kept too moist, leaves may develop fungal spots. It can be propagated by division and rhizomes. |
Landscaping Features
| Desirable Plant Features | Ornamental Flowers, Ornamental Foliage |
|---|---|
| Landscape Uses | Parks & Gardens, Small Gardens, Container Planting, Flowerbed / Border |
Fauna, Pollination and Dispersal
| Pollination Method(s) | Biotic (Fauna) (Insects (Bee)) |
|---|
Plant Care and Propagation
| Light Preference | Semi-Shade |
|---|---|
| Water Preference | Lots of Water, Moderate Water |
| Plant Growth Rate | Moderate |
| Rootzone Tolerance | Well-Drained Soils, Fertile Loamy Soils, Moist Soils |
| Pest(s) | Sucking Insects |
| Propagation Method | Seed, Division, Storage Organ (Rhizome) |
Foliar
| Foliage Retention | Evergreen |
|---|---|
| Mature Foliage Colour(s) | Green |
| Mature Foliage Texture(s) | Velvety / Furry / Tomentose |
| Foliar Modification | Flower/Fruit Bract |
| Foliar Type | Simple / Unifoliate |
| Foliar Arrangement Along Stem | Spiral |
| Foliar Shape(s) | Non-Palm Foliage (Elliptical, Obovate) |
| Foliar Venation | Parallel |
| Foliar Apex - Tip | Apiculate |
| Foliar Base | Cuneate |
| Typical Foliar Area | Mesophyll ( 45cm2 - 182.25 cm2 ) |
| Leaf Area Index (LAI) for Green Plot Ratio | 3.5 (Shrub & Groundcover - Monocot) |
Non - Foliar and Storage
| Stem Type & Modification | Herbaceous |
|---|---|
| Root Type | Underground (Fibrous Root) |
| Specialised Storage Organ(s) | Underground (Rhizome) |
Floral (Angiosperm)
| Flower & Plant Sexuality | Bisexual Flowers |
| Flower Colour(s) | Yellow / Golden, Orange, Brown, Cream / Off-White |
|---|---|
| Flower Grouping | Cluster / Inflorescence |
| Flower Location | Terminal |
| Flower Symmetry | Bilateral |
| Individual Flower Shape | Tubular |
| Inflorescence Type | Spike |
| Ovary Position | Inferior / Epipgynous |
| Flowering Period | Free-Flowering |
| Flowering Habit | Polycarpic |
Fruit, Seed and Spore
| Fruit Classification | Simple Fruit |
|---|---|
| Fruit Type | Dehiscent Dry Fruit , Capsule |
Image Repository
Others
| Master ID | 571 |
|---|---|
| Species ID | 1867 |
| Flora Disclaimer | The information in this website has been compiled from reliable sources, such as reference works on medicinal plants. It is not a substitute for medical advice or treatment and NParks does not purport to provide any medical advice. Readers should always consult his/her physician before using or consuming a plant for medicinal purposes. |
