Sinningia helioana

This species, formerly known by the holding name "Santa Teresa", 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.

Sinningia helioana in bloom in November 2019.

Normally the stem drops before flowering, but in 2019, the stem remained, even though the leaf fell.

1. Flower
2. Leaves
   • Unifoliate habit (almost)
   • Leaf
   • Leaves
   • Leaf back
3. Tuber
4. Propagation
5. Hybridization
6. Comparisons
   • This species with other unifoliate sinningias
   • Comparison to S. defoliata (and S. calcaria)
7. Feature table
8. Publication and etymology

The species Sinningia helioana (sp. "Santa Teresa" prior to publication) is unusual in a couple of respects.  The flowers are borne in striking fashion, on stalks which emerge directly from the tuber.  In this regard, it resembles Sinningia defoliata.  These two species are in the same large group of related sinningias (the Corytholoma clade), although not closely related within that group.

Another species, discovered relatively recently, S. stapelioides, which shares the "blooming from the tuber" trait, is in fact closely related to S. helioana.

Flower

Sinningia helioana blooming in 2012.

The origin of the flowerstalks from the tuber can be seen.

The flower of Sinningia helioana has red lobes and a cream-colored throat.  As can be seen, the cream coloration extends past the opening of the throat.  Within are the anthers, set, it appears, to brush the underside of the beak of a visiting hummingbird, although appearances are deceptive.  The flower in this photo is actually upside down.

The tube is constricted at the base.  It bellies out a little below thereafter, and constricts against just before the corolla flares out into lobes.

As can be seen in both pictures, there are a pair of bulges in the corolla tube where it is enclosed by the calyx.  These pockets are presumably for nectar storage.  They correspond to the upper two corolla lobes, so the flower in the right-side picture is almost upside down.

The flowers on this particular plant on this particular occasion [April 2011] were borne on the simplest possible pair-flowered cyme: two flowers on a peduncle, the second (the one in the picture) in pair-flower position.

Leaves and Growth Habit

Here we have two plants of Sinningia helioana. The plant on the left has the normal single leaf on a stem. The leaf hangs (it was growing on a table in front of a window), as the plant probably does in nature, down the face of a rocky hillside.

The plant on the right, growing in front of the same window [2017], had two leaves on a single stem.

The second picture makes it clear that the stem is not a petiole (leafstalk), since it has two leaves growing from it. This will be even clearer below, when we see pictures of the leaf/stem boundary.

Not Unifoliate

This picture was taken in August 2008.  Instead of one stem and one leaf, this plant has five stems and a sixth on the way, each with its own single leaf.  I used to call this plant "unifoliate", but obviously that's not accurate.  The older the tuber, the more stems and thus the more leaves the plant might have.

For scale, this plant is in a 3.5-inch [9 cm] pot.

The plant habit is unusual as well.  At the 2009 Gesneriad Society convention, Mauro Peixoto showed an interesting photograph of this species in habitat, with the leaves hanging vertically down a slope.  At first glance, the plants could have been unifoliate streptocarpus plants (such as Streptocarpus haygarthii) that have a similar habit.

The Leaf of Sinningia helioana

The Nature of its Leaves

Sinningia helioana usually has one or more leaves, each borne on what looks like a wiry petiole 2-7 cm [1-3 inches] long growing directly from the tuber.  However, observation of a second rudimentary leaf at the base of the blade shows that the apparent petiole is actually a stem. This was confirmed by Alain Chautems.

The picture shows a "leaf stub" on two stalks which would otherwise appear to be petioles.  As the primary leaf matures, the leaf stub usually dries up and falls off, much like the smaller of the two cotyledons on a streptocarpus seedling.

This leaf shows what was probably the parent plant of the two in a previous picture.  The darkness of the leaf was probably due to culture.

It was also growing in a larger pot (5 inches as opposed to the 3" pots in that previous picture).

Leaf Reverse

The back of a Sinningia helioana leaf is usually tinged with red.  How much red there is depends on lighting and (probably) other factors.  This picture shows just about the maximum redness.  The veins remain green (as opposed to the situation in, for instance, S. douglasii, where the veins are red or maroon, and the leaf surface is green.

Tuber

These are flowerstalk shoots growing directly from the tuber. The red color is vaguely reminiscent of the "snow plant" Sarcodes sanguinea of the California Sierras, especially since they both bloom in the winter months.

However, unlike the "snow plant", Sinningia helioana is not parasitic.

Propagation

As usual, the best method for propagating sinningia species is sowing seeds.  Viable seeds germinate faster than cuttings root.  In addition, one obtains more plants.

Even so, this species can be propagated by stem cuttings.  Recall that the apparent petiole (leafstalk) in this species is actually a stem.

A complication is that the stem usually doesn't contain any nodes, from which roots originate in most sinningia stem cuttings.  The easiest way around this is the technique which has proven reasonably successful in propagation of Sinningia defoliata.  Namely, cut a small piece of tuber along with the stem.  The tuber fragment will contain a node or two from which the roots will start more easily.

However, most cuttings of this and similar species do not originate by plan or design.  Instead, they result from certain events which generate pithy Anglo-Saxon expressions of annoyance.  The resulting pieces of plant matter can either be composted or, more usefully, subjected to experimentation.  Make lemonade, right?

The results of one such experiment can be seen here.

Hybridization

The first hybrid created with this species was the work of Dale Martens.  She applied pollen supplied by Karyn Cichocki to S. pusilla, to create the plant she named S. 'Heartland's Flashlight'.

Mr. Wu Jui-Jung of Taiwan has made more crosses with this species.  See some of them here.

Comparison to other species

There are four sinningia species which appear to bloom regularly from the tuber and do not (in my experience) bloom from leafy stems.  A comparison of these four species can be found here.

Three of those species belong to the Corytholoma clade, and are thus reasonably closely related.  The fourth species, Sinningia tuberosa, is in a different clade and thus not closely related.

Sinningia helioana bears a superficial similarity to S. calcaria, to which it is not closely related at all.  A nonblooming S. calcaria with just one leaf may strongly resemble S. helioana, and it may be necessary to examine the tuber or leaf margins to distinguish the two.

Here is a comparison between these two species, with Sinningia defoliata as an additional comparison.