468 PROCEEDINGS OF THE AMERICAN ACADEMY. 
the habit, flowers, and foliage of Galium, but with the leaves in whorls of 
four, axillary inflorescence, involucrate flowers, and usually fleshy fruit. — 
Gen. Pl. 523 (as a section under Galiwm); Benth. & Hook. f. Gen. ii. 
149; Schumann in Fl. Bras. vi. pt. 6, 103; Engl. & Prantl, Nat. 
Pflanzenf. iv. Ab. 4, 154. Galium § Relbunium, Gray, Syn. Fl. N. A. 
i. pt. 2, 40, in part. 
§ 1. Involucre of two bracts: fruit pedicellate. 
1. R. sphagnophilum. A slender delicate annual, pale green, 
glabrous throughout: stems reclining, rooting at the nodes; internodes 
2 to 12 mm. in length: leaves ovate-elliptic, 2 mm. long, one half to 
two thirds as broad, acute, narrowed below into a subpetiolate base: 
peduneles axillary, solitary, 2-bracteate above; bracts minute, less than 
1 mm. in length: corolla not seen: fruit baccate, glabrous, about 1 mm. 
in breadth. — Collected by C. G. Pringle in sphagnum on the Sierra de 
Clavellinas, Oaxaca, altitude 2770 m., 17 October, 1894, no. 5812. 
Probably a near relative of the South American R. humile, Schumann. 
§ 2. Involucre of four bracts: fruit sessile or nearly so. 
* Leaves elliptic to obovate: plant hirsute-pubescent. 
2. R. hypocarpium, Uemst. Annual: stems 1 to 10 dm. Jong, 
pilose: leaves membranous, 5 to 15 mm. long, 3 to 8 mm. broad, rounded 
and usually obtusely mucronate at the apex, entire, ciliate, slightly 
narrowed at the base, pubescent upon either surface, dark green‘above, 
paler beneath: peduncles 5 to 15 mm. long: bracts of the foliaceous in- 
volucre ovate; acute or obtusish, narrowed into a subpetiolate base: 
flowers sessile ; lobes of the corolla ovate, acutish, ciliate: fruit black or 
reddish, hirsute. — Biol. Cent.-Am. Bot. ii. 63. R. hypocarpum, Schum 
Fl. Bras. vi. pt. 6, 112,t. 92. Rubia hypocarpia, DC. Prodr. iv. 5915 
Valantia hypocarpia, L. Syst. Nat. ed. 10, 1307. V. hypocarpa, L. 
Spec. ed. 2, ii. 1491. —Jalapa, O. L. Smith, no. 1570; Mirador, Lieb- 
mann, no. 225; Orizaba, Miiller, nos. 1551, 1699, Sumichrast, no. 468; 
Oaxaca, Pringle, no. 5629; Guatemala, von Tiirekheim (no. 721 of 
Donnell Smith’s sets). 
: * * Leaves ovate-oblong to oblong-lanceolate: plant glabrous. : 
3. R. levigatum, Hemst. Stems cespitose, diffusely branched: 
leaves ovate-oblong or ovate-lanceolate: peduncles axillary: flowers 
sessile and solitary in the involucre: fruit glabrous. — Biol. Cent.-Am- 
Bot. ii. 63. Rubia levigata, DC. Prodr. iv. 591 (whence above descrip” 
tion). Galium levigatum, Bartl. in DC. Prodr. iv. 591. — Collected 18 
‘Mexico by Henke. Specimens not seen. 
