Sinningia richii

Sinningia richii has recently been rediscovered growing in Brazil's Espírito Santo state.  This settles an old problem about the origin of this species, which was otherwise known only from an herbarium specimen in Mexico's Veracruz state, which seemed extremely improbable as the place of origin.

S. richii was known with white flowers; among the new discoveries are plants with yellow flowers.

1. Plant parts
   • Leaves
   • Inflorescence
   • Calyx
   • Hairs
   • Corolla
   • Pollen
2. The new 'Robson Lopes' variety
3. Horticultural aspects
   • Mildew
   • Culture and Pollination
4. Taxonomical Position and Hybridization
5. Feature table
6. External link
7. Publication and etymology

For decades, Sinningia richii was known only in cultivation.  Where the plant originally came from was a mystery.  There was an herbarium specimen in Veracruz state, Mexico, but this was considered a highly unlikely place to find the species.  The only other sinningia found in nature north of the isthmus of Panama is the widespread and adaptable S. incarnata, a great contrast to the finicky and otherwise invisible S. richii.

Growers managed to keep it in cultivation, even without a source in the wild to replenish their collections (the same situation which applies to S. concinna).  It is thanks to the generosity of Bill Price that I have a plant of this species.

In 2008, Robson Lopes rediscovered Sinningia richii in the forests in northern Espírito Santo state (Brazil), a much more plausible location for it than Veracruz.  Moreover, there were both white-flowered and yellow-flowered forms.  According to Mauro Peixoto, these plants were growing in very sandy soil, almost pure sand with a layer of dead leaves over it.  [This may or may not be cultivation guideline; on the Paliavana plumerioides page, I warn against extrapolating conditions in habitat to conditions for growing in a pot!]

The description below applies entirely to my own plant, so it may not apply to other plants in cultivation or to the newly discovered wild plants.

Leaves

My plant has three pairs of leaves, which are plain green with no reddish tinge either on the top or the reverse.  The largest leaves are about 6 inches [15 cm] long and 4 inches [10 cm] wide, but the pot is small, so the plant presumably could be bigger if grown in a larger pot.

Inflorescence

This plant is [as of November 2006] blooming from the axils of the four upper leaves, in the standard pair-flowered cyme pattern.  Although the leaves have no sign of red, the pedicels are dark red, as are the edges of the calyx lobes.  When the flower drops and the calyx lobes age, they turn a very dark red.

Calyx

The calyx is a five-pointed star, and the calyx lobes (particularly the upper three) are spread wide from the corolla.  The calyx lobes, all being in the same plane, present almost a flat surface.

Hairs

The pedicels, the calyx lobes, and the outside of the corolla are all covered with hairs up to 3-4 mm long.  These are longer than the hairs on the leaves themselves.  There must be a reason.

If you know it, speak up.

Corolla

The picture above shows the corolla from below.

The corolla is just about 2 inches [5 cm] to the tip of the lower lobe.  It is tinged with green until it opens, but thereafter is mostly pure white, except for a somewhat shiny greenish "globe" (about 8 mm in diameter) attached to the calyx.

The "globe" opens out into inflated pouch with an opening about 1/2 inch [1.2 cm] wide.  When fully open, the five corolla lobes are almost in a plane, with only the lower lobe extending a little forward.  The lobes are very similar in size, about 1 cm long and 1 cm wide.  The width across the face of the flower is about 3 cm.

There is a groove in the top of the corolla tube (viewed from outside, a broad ridge about 5 mm wide).  The pistil fits into this groove, which keeps the stigma away from the stamens.  Four sturdy white filaments spread laterally across the tube in a sideways arc, and hold the fused anthers firmly, so that even if a pollinator pushes the anthers upward, they will would not come into contact with the stigma.

There are markings on the bottom half of the interior of the corolla: longitudinal stripes alternating with a string of elongated dots.  The color of these markings is somewhere between purple and brown.  The markings are mostly confined to the tube and do not extend to the corolla lobes.  They are somewhat more conspicuous than in the picture (where they are a little washed out by the flash), but it is likely that they are much more conspicuous to bees, the probable pollinator of this species.  White flowers (as in S. eumorpha) are usually "bee violet", reflecting strongly in the near ultraviolet, which is invisible to human eyes but readily visible to bee eyes.

In the picture above, a red object is visible in the opening at base of the corolla.  The picture at the right shows the corolla from underneath, cut open lengthwise.  In this view, the red object seems to be the rudiment of a fifth stamen, only a few mm long.  As in all sinningia flowers, the stamens are attached at their base to the corolla tube, so they fall with the corolla, leaving the female parts of the flower behind.

Pollen

So far I have not gotten any pollen from a flower, so I have not been able to self the plant or put its pollen on another plant.  As of August 2008, I'm still trying.

The 'Robson Lopes' variety

This newly discovered form of S. richii has lemon-yellow flowers.  There are red spots on the outside of the corolla.  Inside the corolla, on the floor of the tube, are three narrow red lines and small red streaks between them.  This picture is from Dave Zaitlin, of his own seed-grown plant.  Somehow he managed to keep the mildew demon away from his door (see below for my struggles with it).

Note the shape of the flower at the right.  Then compare it with the flower I got, in the picture below.  Mine seems closer in shape to the normal white-flowered S. richii, with a wider but apparently shorter tube and wider corolla opening.

This picture shows the flower I got on my plant, which I acquired in the live auction at the 2009 Gesneriad Society convention in Silver Spring, Maryland (just outside Washington D.C.).  This was the only flower it produced, in October 2009, just before it went dormant.  I hope to have better results next year, including a chance of pollination.

At least on my plant, the flower is smaller than that of the normal white variety.  However, this was the first and only flower, with the plant still small.  Next year's flowers (fingers crossed) should give me a better idea of the size, and an opportunity for better pictures.

Mildew

In 2007 my plants of this species were all attacked by mildew.  This was the first time I have had a mildew problem, and S. richii was the first species to get it.  As can be seen from the photo at the top of the page, the plants did not have this problem in 2006.

So far [written in August 2008], the most effective countermeasure to mildew on S. richii has been washing the leaves with soap and warm water.  The leaves still show some damage, but not as much as with chemical remedies, which in most cases destroyed the leaves.  However, washing does not prevent the mildew from coming back.  Prevention seems to be the only real solution.

Both Dale Martens and I have had difficulties with mildew on our plants of S. richii 'Robson Lopes', but so far Dave Zaitlin has been free of it.

Culture and Pollination

The plant had five flowers in 2008, but even so I consider it a difficult plant because of the mildew problem.  I have not succeeded in setting seed on S. richii, either with its own pollen or the pollen of other species in the Corytholoma clade.  For a few days, it looked like I was going to get something from S. barbata pollen, but then the pedicel collapsed.  Try again next year!

Taxonomical Position and Hybridization

Sinningia richii is not particularly close to any other species.  It is a sister species to all the rest of the Corytholoma clade.  As shown in the CrossWords crossing table, hybrids have been made between this species and a few others, but the crosses were invariably sterile.

Feature table for Sinningia richii

External Links

Robson Lopes, a friend of Mauro Peixoto, found S. richii in the wild and has posted pictures of the yellow-flowered form and the white-flowered form, both in habitat.

See a picture on Ron Myhr's Gesneriad Reference Web.

Publication

Sinningia richii was first published by Carl Clayberg in 1968.

I don't know who it was named after.