Sinningia stapelioides

This species, formerly known by the holding name "Pancas", has an interesting growth habit, with (normally) just one stem and one leaf.  The flowers appear in winter, usually after the stem and its one leaf have dropped.

1. In habitat
2. Leaf and Growth Habit
   • Leaf back
   • Stem, not petiole
3. Flowers
   • First flower
   • Flowerbuds
4. Fruit
5. Development
   • Seedlings
   • Older plants
   • Plants after another year
6. Tuber
7. Getting this species to bloom
8. Photographing the flowers
9. Comparison with other unifoliate sinningias
10. Comparison with other unifoliate sinningias
11. Feature table

This species was formerly known and distributed under the holding name S. sp. "Pancas".  The official name was published in 2019.

This new species has intriguing veined and spotted flowers, resembling some in the genus Stapelia (family Apocynaceae).  The composite photo at the right, supplied by Alain Chautems, shows some features of the plant.

The upper left picture shows the flower, with probably the most spotting of any Sinningia species.  Its only real competitor is Sinningia guttata.

The lower right shows the inflorescence borne directly from the tuber, when the plant is leafless.  In this it resembles Sinningia defoliata.  The tuber appears to be imbedded in a rock crevice.

The upper right shows the habitat of this plant.  It grows on an inselberg, literally "island mountain" in German, referring to a large rocky protuberance jutting above the surrounding terrain.  Presumably, possession of a tuber enables the plant to survive in this inhospitable-looking environment.

Growth And Habit

This species has stems that resemble petioles (leafstalks) because they grow directly from the tuber and bear (usually) one leaf.

Sometimes the plant bears two leaves on the same stem, demonstrating that the stem is not a leafstalk.

First flower

I sowed the seed of this species in August 2010.  In November 2014, I saw the first flowerbuds. This picture shows the tuber in December 2014.

In addition to the developing flowerbuds, one can see the shoot buds scattered along the surface of the tuber.  This strongly resembles the appearance of the Sinningia helioana tuber.  This provides one piece of evidence that the two species are closely related.

The flowers of both species are held almost vertically. In nature, as suggested by Alain Chautems's picture above, the tuber may grow at an angle, with the flowers pointing downslope.

Unfortunately, the first corolla dropped without ever opening.  The second dropped almost as soon as it opened.  I set the base of the corolla in a pan of water, in hopes that the pollen would ripen. The corolla opened further, and lasted a couple of weeks.

The plant had two more buds, however, and both of them opened without dropping. 

These corollas are about 6 cm [2.3 inches] long and almost 5 cm [2 inches] across the face.

This species has the standard gesneriad pair-flowered cyme.  The first flower on this cyme is represented by the style at the top.  This is the remnant of the flower that opened and immediately dropped.  The flower on the right is the pair flower, positioned right under the first flower.  The flower on the left is the first cyme side-branch flower (and the only one on this inflorescence).

(The flower on the right dropped less than an hour after this picture was taken.  Moving the plant for photography might have caused it.)

This picture shows a close-up of the contorted anthers.

The corolla's heavy striping and speckling, and its sturdy texture suggest that this species might be bat pollinated.

This picture shows a close-up of the stigma, already dusted with pollen.  The flower is in its second, "female" phase.

Flower cut open to show interior.

Note the stamens attached to the base of the corolla tube.  That is standard for stamens in the Gesneriad family.

Sinningias normally have four stamens, as here.  The anthers are combined into a clump, near the top of the tube.  A couple of blobs of pollen can be seen adhering to the corolla tube.

The pistil is not seen in this picture because it is not attached to the corolla tube but to the ovary, which is attached to the pedicel (flowerstalk).

Fruit

This species has a fat red fruit.
Length of this fruit is 2 cm.

Leaf Back

Here we can see the back of the leaf, with a tinge of maroon, contrasting with the puckers of green along the ribs.

The younger seedlings in the picture above have solid maroon leafbacks, another characteristic shared with S. reitzii.

Tuber

The ball-shaped tuber of this species is often green, even in areas not exposed to light.  Small tubers (less than 1 cm in diameter) are green spheres.

Note that most of the roots on this tuber sprout from the top, rather than the underside.

This ten-year-old tuber, photographed in April 2020. is a very flattened ball, with almost no roots.  The plant has been growing outdoors,  At this point, it gave no sign of reviving for another year of growth.

This is the same plant, photographed about seven weeks later.  A new stem, flattened against the tuber, is developing, with its one new leaf.

The two persistent stems from 2019 can be seen at the top of the picture.

Leaf stub -- or Stem, not Petiole

As in the case of S. helioana, we can discover that what appears to be a petiole is actually a stem.  This is shown by the dried leaf stub just below the blade of the main leaf.  From the surface of the stalk, one cannot see where the boundary between the stem and the petiole is, but the presence of the leaf stub almost certainly indicates that all the "stalk" tissue above it is actually petiole and the tissue below it is stem.

This stem, with two leaves, is clearly not a petiole.

Here, the larger of the two leaves is about 32 cm [12.5 in] long.

Pot diameter is 5 inches [12.5 cm].

This plant is grown outdoors, in full shade (so far).  It has not bloomed (as of 2018, when this picture was taken).

Getting this species to bloom

It has been difficult to get Sinningia stapelioides to bloom.  First, its natural blooming period is mid-winter, not an easy time of year to manage, especially in cold-winter climates. Second, it appears to be very tied to short days, so that artificial light can interfere with the natural signals to stimulate blooming.

My experience, both positive and negative, suggests the following:

• Grow the plant in natural light, if possible.
• The bigger the pot, the better.
• Lots of water. Keep it wet. Maybe when the leaf drops, withhold fertilizer.
• Drainage isn't important. The soil these plants are growing in [winter 2017-2018] is quite dense.

The photograph at the right shows two plants with roughly equal-sized tubers, growing in the same window, and thus receiving the same light and water. The plant in the bigger pot is blooming, the other is not.

Photographing the Flowers

Because the flowers hang almost vertically downward, it can be difficult to photograph the face of the corolla or its interior.  The best way to get a good picture is to find a high perch (eye level or higher) with a more or less neutral background and photograph upward.  That is how the photograph at the top of this page was taken.

The photograph on right shows the same plant a minute later, in the same location, photographed on the level.