Unifoliate Sinningias

Some sinningias have only one leaf at a time.

This picture shows the four species of Sinningia that can have as few leaves as one during a growing season. They also have the appearance of bearing leaves directly from the tuber, although what looks like a petiole is in fact an abbreviated stem.

Sinningia defoliata and Sinningia tuberosa have fleshy, herbacious stems that strongly resemble petioles. Sinningia helioana and Sinningia stapelioides have wiry stems. Of the four species, S. tuberosa is in the Sinningia clade, while the other three are in the Corytholoma clade.

In tuber shape, S. tuberosa is again the odd creature out, with a gnarly, multi-branched tuber, while the other three have more or less standard disk-shaped (convex) tubers.

One other feature that at least three of these species share is durable dried leaves.

Here is a comparison among the four species.

	S. defoliata	S. helioana	S. stapelioides	S. tuberosa
Growth habit	One or more short (less than 2 cm) single-leaved stems, giving the appearance of leaves growing directly from tuber	One or more (usually) single-leaved wiry stems (4-10 cm long), giving the appearance of petioles growing directly from tuber	One or more (usually) single-leaved wiry stems (4-10 cm long), giving the appearance of petioles growing directly from tuber	Multiply branched stems, each branch ending in one or two leaves.
Leaf shape (for unifoliate habit)	Elliptical, up to 24 inches long, length-to-width usually less than 2:1	1-8 inches long, length-to-width is about 3:1	4-10 inches long, length-to-width is about 1.5	2-6 inches long, almost round, length-to-width would be about 1 were it not for the relatively narrow tip
Leaf margin	Smooth	Almost smooth, slight indentations	Pronounced indentations	Almost smooth, slight indentations
Leaf back	Green (no trace of red except in young leaf, when the leaf top can be reddish too)	Reddish, secondary veins in low relief	Reddish, secondary veins in high relief	Green, secondary veins in moderate relief
Tuber	Disk-shaped, convex, can have stubs from previous years' stems	Disk-shaped, convex	Disk-shaped, convex	Like a caudex, usually with multiple branches
Flowering season	Winter	Winter	Winter	Summer
Inflorescence	Raceme, emerging directly from tuber, flowers held more or less horizontally	Cyme with peduncle, emerging directly from tuber, flowers pendant	Cyme with peduncle, emerging directly from tuber, flowers pendant	Raceme, directly from tuber or above-ground branches of tuber
Corolla shape and color	Tubular, red with no conspicuous markings	Tubular, red with white throat	Trumpet-shaped, heavily spotted	Tubular, orange-red or red
Calyx	Dark red	Reddish, short	During development, red and completely encloseding bud. Later, with reddish tips on calyx lobes.	Short, red with green tips on lobes.