Part 1, 1918] RUBIACEAE 39 
1. Arcytophyllum lavarum K. Schumann; (Donn. Smith, Enum. PI. 
Guat. 5: 36, assynonym. 1899) Standley, Contr. U. S. Nat. 
Hero: 183 127... 1916. 
Mallostoma lavarum Donn. Smith, Enum. Pl. Guat. 5: 36; hyponym. 1899. 
Much branched rigid shrub, 1—2.5 dm. high, glabrous except upon the corollas, the branches 
dark brownish-gray, the branchlets sharply angulate, brown, densely leafy; stipules triangular 
or ovate, 1.5 mm. long or shorter, coriaceous, dentate or laciniate; leaf-blades broadly ovate or 
ovate-oblong, 4-6 mm. long, 2—3 mm. wide, abruptly contracted at the base into a very short 
petiole, rounded or very obtuse at the apex, lustrous above, paler beneath, the costa very 
broad and prominent beneath; flowers crowded in small dense terminal cymes, the pedicels 
stout, 2 mm. long or shorter; hypanthium at anthesis less than 1 mm. long; calyx-lobes 
broadly ovate, obtuse or acute, much longer than the hypanthium, with 1 or more setae 
between each pair; corolla salverform, 4-5 mm. long, glabrous outside, the tube thick, the 
lobes ovate, obtuse, shorter than the tube, white-villous within; capsule subglobose, 1.5—2 
mm. long, three fourths inferior; seeds about 0.8 mm. long, oval to orbicular, concavo-convex, 
coarsely punctate, black. 
TYPE LOCALITY: On bare rock slopes at the summit of Chiriqui Volcano, Panama, at an altitude 
of 3,374 meters. J 
DISTRIBUTION: Summits of the highest mountains of Costa Rica and Panama. 
III. RONDELETIEAE. Shrubs or trees, rarely herbs. Stipules usually 
entire. Flowers perfect; corolla symmetric, the lobes imbricate or contorted. 
Anthers dorsifixed. Ovary 2-celled; ovules numerous. Fruit capsular, 
2-celled. Seeds numerous, horizontal, minute, exalate or rarely winged; 
endosperm fleshy; embryo small, clavate or cylindric. 
Corolla-lobes imbricate. 
Calyx-lobes dissimilar, one of them expanded into a large petiolate 
colored limb. 15. WARSZEWICZIA. 
Calyx-lobes similar, none of them expanded into a petiolate limb. 
Capsule half superior; shrubs. 16. RACHICALLIS. 
Capsule inferior or nearly so. 
Calyx-tube much longer than the lobes; flowers 4-parted, axillary; 
ovary oblong; stamens inserted in the throat of the corolla. 17. NEOMAZAEA. 
Calyx-tube short or obsolete. 
Plants shrubs or trees; corolla not rotate; capsule septicidal or 
loculicidal. 
Calyx bilobate, deciduous; corolla 5—7-parted; flowers axil- 
lary; stamens inserted in the throat of the corolla. 18. STEVENSIA. 
Calyx 4-6-lobate, persistent; inflorescence axillary or 
terminal. 
Stamens inserted in the lower part of the corolla-tube; 
flowers usually 6-parted. 19. ACROSYNANTHUS. 
Stamens inserted in the throat of the corolla; flowers 
usually 4- 5-parted. 20. RONDELETIA. 
Plants herbaceous; corolla subrotate; capsule opening at the 
apex. 21. PINAROPHYLLON. 
Corolla-lobes contorted. 
Plants trees or shrubs. 
Corolla-tube very short, shorter than the lobes. 
Corolla glabrous within, 4-parted; filaments not appendaged. 22. DEPPEA. 
Corolla villous within, 5-parted; filaments appendaged at thebase. 23. ELAEAGIA. 
Corolla-tube elongate, usually much longer than the lobes. 
Corolla tubular, glabrous within; filaments elongate; flowers 
4-parted. 24. OMILTEMIA. 
Corolla salverform, subrotate, or funnelform; filaments short. 
Tube of the corolla several times as long as the lobes, these 
oblong; anthers exserted. 25. LINDENIA. 
Tube of the corolla less than twice as long as the lobes, these 
lance-linear; anthers included. 26. STYLOSIPHONIA. 
Plants herbaceous. 
Stamens included; leaves opposite. 27. SIPANEA. 
Stamens exserted; leaves verticillate. 28. LIMNOSIPANEA. 
