ON SOUTH-AMERICAN APOCYNACEÆ. 101 
20. THYRSANTHUS PUBESCENS, nob.: Forsteronia pubescens, A. DC, l. c. p. 436; Müll. Z. c. p. 104. In 
Brasilia: v. s. in herb. meo, Ceará (Gardner 1761). 
Its branches are oppositely ramose, studded with small white verrucous lenticels, sub- 
pubescent, the axils being 1-2 in. apart; leaves obovate, subacute or obtuse at the base, 
rounded or emarginate at the mucronulate apex, flaccidly chartaceous, green above, 
subpubescent, with yellowish slender midrib and oblique nerves, with 2 collateral 
fulvous glands among the hairs at the base of the midrib, pale beneath and covered with 
fine short tomentum, especially on the nerves and transverse veins, between which are 
very numerous fascicles of short hairs, 3-43 in. long, 13-23 in. broad, on pubescent 
petioles 3-7 lines long; panicle terminal, spiciform, 4 in. long, covered with reddish 
pubescence, alternately branched at intervals of 2-4 lines, with short branches, the lower 
ones 1 in. long, diminishing upwards, each on a bare support, carrying an almost capi- 
tate head of small dense flowers on bracteolated pedicels 3 line long; sepals acute, 3 line 
long; corolla 23 lines long; the acute segments 1} line long, with dextrorse convolution ; 
stamens glabrous, half-exserted ; anthers acuminate, furnished at the base with 2 parallel 
prongs. 
21. THYRSANTHUS AFFINIS, nob.: Forsteronia affinis, Müll. l. c. p. 100, tab. 30. In prov. Alt. Ama- 
zonas et confinibus : v. s. in herb meo Tarapota (Spruce 4493). 
Spruce's plant agrees sufficiently with Müller's drawing. "The branchlets are slender, 
subquadrangular at the summit, 'striolate, with small lenticels, the axils 3-1 in. apart; 
leaves oblong elliptic, subacute at the base, as in the drawing (not cordate as in the text), 
with a short, abrupt, subacute acumen, very glabrous, rigidly membranaceous, darkish 
green above, subopake, suleate along the midrib and oblique slender nerves, with 
2 whitish glands at the base of the midrib, pale ferruginous and opake beneath, with 
prominulent red midrib and nerves, finely reticulated veins, 34-44 in. long, 1-2 in. 
broad, on suleate petioles 3-31 lines long; panicle terminal, 4 in. long, remotely and 
very laxly branching from the base; lower branches slender, 2 in. long, bare at the base 
for half their length, again branched, branchlets 3-4 lines long, bearing at their summits - 
few very small flowers on bracteolated pedicels 1 line long, all glabrous; sepals ovate 
acuminate, pruinose, 1—2 line long; corolla pruinose, 13 line long; segments acute, twice 
as long as the tube, woolly within, dextrorsely convolute; anthers dorsally pilose, half- 
exserted; disk of 5 oblong lobes, as long as the 2 glabrous ovaries. 
22. THYRSANTHUS PLACIDUS, nob. In Alta Amazonas : v. s. in herb. Mus. Brit. Tarapota (Spruce 4295). 
A species very near the preceding, differing in its pubescent leaves and spicate 
inflorescence; branches very slender, puberulous, with axils ¿-1 in. apart; leaves 
elliptic, acute at the base, constricted at the summit into a short acumen, flaccid, green 
and subglabrous above, with immersed slender nerves, with 2 small glands at the base of 
the midrib, paler beneath, yellow, covered with short soft pubescence, especially on the 
prominulent nerves, 3 in. long, 13 in. broad, on pubescent channelled petioles 2 lines 
long; panicle terminal, 34 in. long, thyrsoid, pubescent, on a short peduncle, with 
branches 4 in. long, 2-4 lines apart, spreading, again divided, each bracteolated branch- 
