566 ASCLEPIADE® (Brown). | Xysmalobium. 
Corolla-lobes without a gib- 
bosity on the inner face: 
Corolla-lobes 12-2 lin. 
long, yellow... ... (18) Gerrardi. 
Corolla-lobes 1-14 lin. 
long, _ greenish - white, 
often purplish down the 
back»: : Sis % ... (14) parviflorum. 
Corolla-lobes very spreading or 
reflexed ; corona-lobes subcon- 
tiguous, ovoid to subglobose, not 
nearly twice as long as broad... (15) asperum. 
Umbel solitary, terminal ; peduncle 13-4 
in. long: 
Corolla yellow; corona-lobes ob- 
long, erect, distinctly exceeding 
the staminal column, with slightly 
incurved tips... ass ... (16) tysonianum, 
Corolla brownish or greenish-brown ; 
corona-lobes linear-oblong to 
narrowly ovate, slightly  di- 
vergent-spreading, not exceeding 
the staminal column nor incurved 
at the tips... ae a6 ... (17) prunelloides. 
Corolla white or greenish-white, 
tipped with purple, at least on 
the backs of the lobes; corona- 
lobes erect, orbicular in dorsal 
outline, rather shorter than the 
staminal column ... as ... (18) Baurii. 
1. X. involucratum (Decne in DC. Prodr. viii. 520); tuber 
somewhat carrot-like ; stems 1-2 to a tuber, erect, 4-12 in. long, 
leafy, glabrous with 2 pubescent lines, or pubescent all round; 
leaves numerous, opposite, 2-43 in. long, 8-8 lin. broad, linear, 
acute, erect or ascending, revolute along the margins, varying from 
glabrous to pubescent on one or both sides; umbels 1-5 to a stem, 
usually subeorymbose at its summit, occasionally spaced along the 
upper part, pedunculate, hemispherical, 20—30-flowered, involuerate 
with several linear-subulate spreading or reflexed bracts 2-2} lin. 
long; peduncles 3-12 in. long, pubescent ; pedicels 4—5 lin, long, 
pubescent ; sepals 1 lin. long, nearly 2 lin. broad, lanceolate, acute, 
pubescent, reflexed; corolla entirely reflexed, slightly pubescent on 
the back, glabrous within, yellowish-green ; lobes 13—1+ lin. long, 
% lin. broad, oblong-lanceolate, subacute ; corona-lobes arising about 
1 lin. above the base of the staminal column, and only reaching to 
about its middle, % lin. long, ovoid, acute, entire or bifid, thick and 
fleshy, erect, laterally sessile, with the apical part free and applied to 
the basal part of the anthers ; staminal column 12 lin. long ; filament 
part short, cylindric; anther part somewhat barrel-shaped ; anthers 
erect, rhomboid; their appendages small, elliptic-ovate, acute, 
inflexed over the apex of the style, and their wings very broadly 
triangular, very prominent and minutely notched at the middle, 
narrowing towards the base and apex ; style-apex small, pentagonal, 
