13. Thibaudia RUIZ & PAVON ex JAUME SAINT-HILAIRE Expos. Fam. 1: 362 (1805).
-- Lectotype: Thibaudia mellifera RUIZ & PAVON ex JAUME SAINT-HILAIRE.
Eurygania KLOTZSCH, Linnaea 24: 15, 26 (1851). -- Type: Eurygania parvifolia KLOTZSCH.
Calopteryx A. C. SMITH, J. Arnold Arbor. 27: 100 (1946). -- Type: Calopteryx insignis A. C. SMITH.

References: SMITH, A. C., Studies of South American plants, XI. Noteworthy species of Hippocrateaceae and Vacciniaceae. J. Arnold Arbor. 27: 86--120, 4 figs. (1946).

Epiphytic or terrestrial shrubs. Leaves alternate, coriaceous or subcoriaceous, margin entire or crenulate, pinnate or plinerved, petiolate. Inflorescence axillary or terminal, pin-cushion type (glomerulate), fasciculate, racemose, or paniculate, rarely ramiflorous, with few to many flowers; pedicel deciduously bibracteolate. Flowers 5-merous, without odor; aestivation valvate; calyx articulate with the pedicel or rarely continuous; hypanthium short-cylindric or campanulate, terete, occasionally narrowly 5-angled, or rarely conspicuously winged to the sinuses; limb erect to slightly spreading distally; lobes triangular, subacute; corolla cylindric to subcylindric, terete, occasionally 5-angled, rarely weakly to strongly winged, the lobes triangular or oblong, subacute; stamen 10, equal, often nearly as long as the corolla; filaments equal, distinct or connate, lacking spurs; anthers equal, dorsally attached near the base, firm or membranous, lacking disintegration tissue; thecae smooth or slightly granular; tubules about as long as the thecae, dehiscing by elongate introrse clefts; pollen lacking viscin threads; ovary inferior; style filiform, about as long as the corolla or slightly exserted. Fruit a berry.

Thibaudia is a genus of about 60 species with one species in Panama and Costa Rica and the others ranging from Colombia to Bolivia and eastward to Suriname and Guayanan Brazil.


Key to the Species of Thibaudia
1a.
Calyx continuous with pedicel, not articulated.
2a.
Both calyx and corolla strongly, sometimes broadly, and conspicuously winged
............................................................................................T. litaënsis
2b.
Calyx and corolla terete, or sometimes angled or narrowly winged, but not conspicuously winged.
3a.
Inflorescence fasciculate, subtended by a persistent series of narrowly triangular to linear-lanceolate, striate bracts to 15 x 2 mm
...................................................................................T. sessiliflora
3b.
Inflorescence short- or long-racemose, 0.2--9 cm long, subtended by deciduous, oblong to ovate, membranaceous bracts to 2 x 1 mm.
4a.
Rachis 2--9 cm long; inflorescence 15--30-flowered; leaves 2.5--7.5 cm wide
..........................................................................T. floribunda
4b.
Rachis 0.2--1.1 cm long; inflorescence 1--10-flowered; leaves 5.5--14 cm wide.
5a.
Inflorescence 1-flowered; rachis 2--3 mm long; calyx hypanthium winged (narrowly and inconspicuously) at anthesis; corolla red at base with green apex; Oriente
.................................................................T. lateriflora
5b.
Inflorescence 2--10-flowered; rachis 4--11 mm long; calyx hypanthium terete at anthesis; corolla red at base with white apex; Cordillera Occidental
.................................................................T. inflata
1b.
Calyx articulate with pedicel.
6a.
Filaments distinct.
7a.
Corolla less than 15 mm long; anther thecae about equalling the tubule in length or shorter.
8a.
Leaves less than 4 x 2 cm, pinnately nerved; pedicel 1--2 mm long; flowers pilose; calyx 9--14 mm long, the lobes 5--9 mm long
...........................................................................T. jorgensenii
8b.
Leaves 7--23 x (3.5-) 4--9 cm, plinerved; pedicel 10--20 mm long; flowers glabrous; calyx 5--6.5 mm long, the lobes equal to or less than 1 mm long.
9a.
Leaves 7--13 cm long, the margins sinuate-crenate, the base strongly cordate and subauriculate; pedicel 10 mm long; calyx limb bearing 5 circular glands at base
.................................................................T. clivalis
9b.
Leaves (8-) 12--23 cm long, the margins entire, the base rounded or obtuse, often narrowly attenuate; pedicel 17--20 mm long; calyx limb without glands
..................................................................T. lugoi
7b.
Corolla greater than 20 mm long; anther thecae usually two or more times longer than the tubules.
10a.
Leaves pinnately nerved with 4--7 pairs of nerves arising at high angles, ovate, the base rounded and subcordate, usually clasping the stem; pedicel 4.5--6 cm long
...........................................................................T. pachyantha
10b.
Leaves plinerved with 2--3 pairs of nerves arising at low angles and running the length of the leaf, sometimes the inner 1--2 pairs of nerves arising several centimeters above the base, elliptic, narrowed at both ends, if the leaves are basally rounded, then the leaves clearly petiolate and not clasping the stem; pedicel 1.8--4.5 cm long.
11a.
Inflorescence subfasciculate, 2--6-flowered; rachis to 0.6 cm long; calyx ca 14 mm long; corolla 2 times calyx length
.................................................................T. harlingii
11b.
Inflorescence racemose, 6--15-flowered; rachis 1.5--4 cm long; calyx 6--10 mm long; corolla 3--4 times calyx length.
12a.
Calyx hypanthium 2 mm long, basally apophysate; calyx limb 3--5 times hypanthium length; corolla 4 times calyx length; calyx 6 mm long; petiole to 5 mm long
......................................................T. andrei
12b.
Calyx hypanthium 3--5 mm long, basally rounded or truncate, not apophysate; calyx limb 1.5--3 times hypanthium length; corolla ca 3 times calyx length; calyx 8--11 mm long; petiole 5--20 mm long
......................................................T. martiniana
6b.
Filaments connate.
13a.
Inflorescence paniculate
...................................................................................T. albiflora
13b.
Inflorescence racemose, fasciculate, or flowers solitary.
14a.
Leaves > 10 cm long
..........................................................................T. gunnari
14b.
Leaves < 4 cm long.
15a.
Flowers (calyx, corolla, and pedicel) densely tomentose to woolly
.................................................................T. anomola
15b.
Flowers glabrous to short-pilose.
16a.
Leaves obovate to oblong-obovate, 3--6 cm long, the base long-tapering and cuneate, the apex rounded and retuse
........................................................T. retusifolia
16b.
Leaves ovate to oblong, 1.2--3 cm long, the base rounded to subcordate, the apex acute to rounded, not retuse.
17a.
Leaves flat, soft pilose on both surfaces, apically subacute and callose-apiculate; bracts subtending inflorescence 8--10 mm long; flowers more or less sessile; corolla 10 mm long
...............................................T. steyermarkii
17b.
Leaves often marginally revolute, glabrous, apically obtuse to subacute; bracts at base of inflorescence < 2 mm long; flowers with pedicel 5--8 mm long; corolla 17--19 mm long, short-pilose to puberulent, lobes to 5 mm long
...............................................T. parvifolia