94 ON SOUTH-AMERICAN APOCYNACEX. 
Tayrsantuus, Benth. (non Elliot nec Schrank); Thenardia, Benth. (non Kunth) ; Forsteronia, Meyer 
(in parte), Müller, Benth. & Hook. Sepala 5, parvula, ovata, subacuta, intus squamulis 2-3 minimis 
preedita. Corolla parva; tubus cylindricus; segmenta oblonga, subzequilatera, tubo longiora, seepius 
intus glabra, raro lanata aut villosa, paullo dextrorsum convoluta, dein subrotata. Stamina 5, 
tubo corolle inclusa, aut apice semiexserta ; filamenta brevia; anthere lineari-oblonge, acuminate, ` 
imo furcis 2 parallele elongatis armate, in conum coherentes. Discus e lobis 5 oblongis, seepius 
discretis, ovaria cingens ; ovaria 2 distincta, eo non rarius longiora; sty/us brevis, glaber; clavuncula 
cylindriee 5-sulcata, imo membrana peltata indusiata; stigmata 2, parva, terminalia. Folliculi 2, 
tenuiter teretes, horizontaliter divergentes, sulco ventrali dehiscentes, suturze marginibus in placen- 
tam cylindricam introflexz:e. Semina plurima, imbricatim suspensa, lineari-oblonga, compressis- 
sima, lateribus membranaceis paullo incurvatis, levia et ecomosa, hilo centrali signata; embryo 
incognita. 
Frutices scandentes Americe meridionalis, sepius glabri ; folia opposita, rarius ternatim verticillata, 
oblonga, petiolata, seepius glabra; panicule axillares aut terminales, laxe thyrsoidee aut capitate ; 
flores numerosi, parvuli, inconspicui. 
1. THYrsaNTHUS SCHOMBURGKIL, Benth. Hook. Journ. Bot. iii. 245; A. DC. l. c. p. 387 : Forsteronia 
Schomburgkii, A. DC. l. c. p. 438 (excl. syn.) ; Müll. Flor. Bras. l. c. p. 107 in nota. In Guiana 
Brit. (Schomb. 37, 57, 556, 557) : v. s. in herb. meo er loc. cit. (Schomb. 537). 
This typical species has scandent, rugous, verruculous branches 2 lines thick, with 
patently divergent branchlets; its opposite leaves have a reddish hue, are obtuse at the 
base, with a narrow recurved acumen 4 in. long, quite glabrous, palish green above, 
sulcate along the midrib, which has 2 very minute glands at its base, several oblique 
subimmersed nerves, beneath rubescently ferruginous, opake, with prominulent nerves 
and reticulated veins, 3-5 in. long, 14-12 in. broad, on slender channelled petioles 1 line 
long; panicle terminal, 3 in. long, with opposite ramifications 6 lines long, 4-7 lines 
apart, dichotomous, each ray bearing an almost capitate cluster of flowers; pedicels 
1 line long, with 2 lanceolate bractlets at the base; sepals acute, 3 line long, with 
2 minute scales at the base of each within; tube of corolla 2 line long, glabrous, with a 
narrow pilose ring above its base; the 5 segments linear-oblong, 1 line long, glabrous 
within, expanded, with dextrorse convolution; stamens inserted in the pilose ring, . 
almost wholly included in it; filaments short; anthers cohering together and to the 
elavuncle, acute at their summit, 2 obtuse prongs at their base. 
2. THYRSANTHUS LAURIFOLIUS, nob.: Thenardia ? laurifolia, Benth. J. c. p. 246: Forsteronia laurifolia, 
A. DC. l. c. p. 438; Müll. Z c. p. 106. In Amazonas: v. s. in herb. meo Rio Negro ad Barcellos 
(Schomb. 953), Rio Negro ad Barra (Spruce 999). 
A species very near the preceding, and by mistake referred to Thenardia. Its 
branches are stout, rugous, griseous, glabrous, with divaricating branchlets striate and 
lenticellate, with axils 1-14 in. apart; leaves elliptic oblong, acute, and inequilateral 
at the base, gradually acuminate, margins somewhat crenulate, chartaceous, very 
glabrous, glaucous green above, with a slender midrib and subimmersed fine nerves, 
furnished at the base of the midrib with 2-3 yellow granular glands, ferruginous, opake 
beneath, with prominent midrib and nerves 4—42 in. long, 11-12 in. broad, on sub- 
reflexed petioles 3-5 lines long; panicles opposite or terminal, on short peduncles 
