The flowers in this image are ''inverted'' (the equivalent latin-derived term ''resupinate''). This is a character trait with which I've long had difficulty. But now I think I've finally figured it out!! So below I'll try to describe what this means...in two steps.

First, you need to know this: for bilateral Nemacladus flowers, the 3-lobed lip is considered the ''upper lip''; and the 2-lobed lip is considered the ''lower lip''. Also, the base of stamen tube is usually declined towards the lower lip, and its tip is bent ''upwards'', pointing in the direction of the 3-lobed upper lip. [Note: Some Nemacladus species have flowers that appear more or less 'radially symmetric', meaning the five corolla lobes don't appear separated into distinct 2- and 3-lobed lips. On flowers of these species, the direction of the bend in the stamen-tube tip can be used to define ''upper'' and ''lower'' lips. The stamen-tube tip points towards the upper lip.]

The second step in understanding of meaning of the ''flowers inverted character'' for Nemacladus involves a minor thought experiment. Imagine using your thumb and forefinger to nimbly press the base of the slender pedicel of a Nemacladus flower against its point of attachment to the flowering stem. Now, starting from the base of the pedicel, gently slip your fingers up the flowering stem (without twisting the pedicel) until the base of the flower is being held right next to the flowering stem...facing up, with its axis parallel to the flowering stem. Then the flower is considered inverted if the lower (2-lobed) lip ends up adjacent the flowering stem, and the upper (3-lobed) lip is on the far side of the flowering stem. (Equivalently, the flower is inverted if the bend in the stamen tube is pointing away from the flowering stem.) Of course if, on the other hand, the 3-lobed lip is closer to the flowering stem, then the flowers are not inverted.

This thought experiment (or the real thing if you have a plant available in the field) is usually necessary, because Nemacladus flowers often dangle on their slinky pedicels in such a way that it's hard to make out in which direction the lower or upper lips are oriented with respect to the adjacent flowering stem.

Also, remember these are plants...that is, complex organisms which mutate and express all sorts of variation in their dynamic interplay with the environment...and they don't always read the floras and follow the rules! :-) So it's best to check this character for a number of flowers and, hopefully, a general trend will become apparent on a given plant.

If you'd like to practice recognizing this character, you can check out, compare, and scrutinize the following CalPhotos images:

Two species with inverted flowers: N. secundiflorus; and N. longiflorus.

Two species with non-inverted flowers: N. orientalis; and N. interior.