Hoya lauterbachii is a magnificent and highly sought-after Hoya species, renowned for having some of the largest and most impressive flowers in the entire genus. It belongs to the "Eriostemma" section of Hoyas, which often signifies plants with thicker, pubescent leaves and larger blooms that prefer specific care conditions.
Hoya lauterbachii is native to New Guinea. It grows primarily in the wet tropical biome, typically found in lowland and hill forests. Some sources also mention its presence in the Philippines, though New Guinea is consistently cited as its primary native range.
The species was formally described by Karl Moritz Schumann in 1896. It was named in honor of Dr. Karl Lauterbach, a German botanist and explorer who contributed significantly to the flora of New Guinea.
The original publication details are:
Schumann, K. (1896). Monatsschrift für Kakteenkunde, Vol. 6, p. 7.
You can find references to this publication on botanical databases like Plants of the World Online (POWO) by Kew Gardens: https://powo.science.kew.org/taxon/urn:lsid:ipni.org:names:98532-1. While the full text of "Monatsschrift für Kakteenkunde" might require access to botanical libraries or specialized archives, its publication details are widely cited.
Key Characteristics
Leaves: Hoya lauterbachii has large, ovate leaves that are deep green and often have a slightly fuzzy or velvety texture. They are held on thick, sturdy stems, providing a lush backdrop for the remarkable flowers.
Growth Habit: It's a vigorous vining plant with thick, sturdy vines that can reach several meters in length. It thrives when given robust support to climb (like a large trellis or moss pole) or can be grown in a large hanging basket where its weighty vines can cascade.
Flowers: The flowers are truly the showstopper. They are some of the largest in the Hoya genus, often reaching 7-8 cm (2.5-3 inches) in diameter, and are cup-shaped with strongly reflexed (bent backward) corolla lobes. The color is typically a striking deep crimson, reddish-copper, or dark red, with a contrasting yellowish or cream-colored center/corona. The flowers have a velvety texture and are covered in fine hairs both inside and out. They are borne in large umbels, with about 7-8 individual flowers per cluster, which together can form a bloom "ball" the size of a small soccer ball. The flowers often have a strong, sweet fragrance, frequently described as chocolate-like, especially at night. They can last for several days to over a week.
Eriostemma Group: Being part of the Eriostemma section, it shares characteristics with other members of this group, such as often having fuzzy foliage and requiring more light and warmth to thrive and bloom.
Care Requirements for Indoor Cultivation
Light: Requires very bright, filtered light to encourage blooming. While it appreciates plenty of light, avoid harsh, intense midday direct sun, which can scorch its leaves. A few hours of direct morning or late afternoon sun can be beneficial. It often needs the brightest location you can provide indoors.
Watering: This Hoya prefers periods of dryness between waterings but does not like to be left completely dry for extended periods, especially when actively growing. Allow the top few inches of the soil to dry out before watering thoroughly. Ensure the pot has excellent drainage to prevent waterlogging and root rot. Reduce watering significantly in winter.
Humidity: Thrives in moderate to high humidity (ideally above 60%). While it can tolerate average household humidity, higher levels will promote healthier growth and better flowering.
Temperature: Prefers warm temperatures, ideally between 21−35∘C It is not cold-hardy and must be protected from temperatures below 10∘C.
Soil: Requires a very well-draining, airy potting mix
Potting: Due to its vigorous growth and large size at maturity, Hoya lauterbachii will eventually need a large, sturdy pot with good drainage. Like many Hoyas, it can be a bit snug in its pot, but given its size, it will need a repot much faster.
Hoya lauterbachii is most often compared to Hoya gigas, another large-flowered Eriostemma species from New Guinea. The primary distinguishing factor is the flower fragrance: H. lauterbachii is famous for its pleasant, chocolate-like scent, while H. gigas is often described as having an unpleasant or even rotting scent. The flower color and morphology can also differ subtly upon close inspection.
Tips
Support System: Due to its large size and vigorous climbing habit, provide a strong and tall trellis or other support from an early age.
Patience: While it can be a relatively fast grower, it needs to reach a certain level of maturity and size before it starts producing its massive blooms. Patience and consistent optimal care are key.
Don't Cut Peduncles: The plant will re-bloom from the same flower spurs (peduncles) year after year. Never cut these off.
Air Circulation: Good air circulation is crucial, especially with high humidity, to prevent fungal issues on leaves and flowers.
Hoya lauterbachii is a truly magnificent specimen for the dedicated Hoya collector, offering an unparalleled floral display with its giant, fragrant, and richly colored blooms.
