Table 2.
Histochemical analysis of labellar papillae
| Foods present in papillae | |||||
| Taxon | Accession no. | Type of papilla | Protein | Starch | Lipid |
| M. acutifolia Lindl. | MMB64 | o, cl | + | + ce | + s |
| M. buchtienii Schltr. | KLD199813 | o | + | + | – |
| M. camaridii Rchb.f. | KLD199920 | c | + | – | – |
| M. chrysantha Barb. Rodr. | S19940012 | a | + | – | – |
| M. jenischiana (Rchb.f.) Garay & C. Schweinf. | S19980077 | c | + | + | – |
| M. jocunda Lehm. & Kraenzl. | S19990297 | o | + | + | – |
| M. lexarzana Soto Arenas & F. Chiang | KLD199706 | a | + | – | – |
| M. mosenii Kraenzl. var. hatschbachii (Schltr.) Hoehne | S19980051 | c | + | – | – |
| M. pseudoreichenheimiana Dodson | MMC16 | o | + | – | – |
| M. reichenheimiana Endres & Rchb.f. | MMA50 | o | + | – | – |
| M. rufescens Lindl. | S19980055 | o, cl | + | + | + |
| M. cf. setigera Lindl. | S19980057 | o | + | + | – |
| M. tenuibulba E.A. Christenson | MMB16 | c, o, cl | + | + ce | + s |
| M. tenuifolia Lindl. | S00000282 | v | + | – | – |
Types of papillae: c = conical; cl = clavate; o = obpyriform; v = villiform; a = absent.
+ and – indicate presence and absence, respectively, of food substance, whereas ce indicates that the food substance is largely concentrated in the central papillae of the labellum and s that the substance is secreted onto the labellar surface.