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1. M. barbigerum Scheele. Leaves from ovate-oblong to narrowly lanceolate, cus- 
pidate-acuminate, rounded at base: peduncles shorter than petioles, often very short: 
corolla about 4mm. long, its linear lobes strongly white-villous within: slender-subu- 
late scales of the crown on base of corolla,—Open woods and rocky banks, southern 
and western Texas. 
2. M. Palmeri Watson. Leaves lanceolate, acutish or obtuse at base: cymes sub- 
sessile or short-peduncled: corolla not over 3mm. long, its oblong lobes merely puber- 
ulent within: lanceolate-acuminate or ovate-subulate scales of the crown inserted at 
base of extremely short column.—Southern and western borders of Texas. 
8. VINCETOXICUM Mench. 
Mostly twining herbs, with opposite leaves, small usually dull flowers 
in axillary umbellate clusters, 5-parted calyx, rotate 5-parted corolla, 
crown (in ours) of 5 thin or thinnish scales or processes either distinct 
or barely united at base, and anthers, smooth pods and seeds much as in 
Asclepias. 
1. V. palustreGray. Stems filiform, freely twining upon rushes and saline grasses: 
leaves linear, acute, fleshy, 2.5to5cm. long, 2 to 4mm. broad: peduncles longer than 
leaves: corolla greenish; scales of crown oblong-obovate, retuse or emarginate. 
(Seutera maritima Decaisne),—Salt marshes along the coast, 
9. GONOLOBUS Michx. 
Mostly twining herbs or shrubs, with opposite cordate leaves, usually 
corymbose-umbelled greenish or dark purple flowers on peduncles rising 
from between the petioles, 5-parted calyx, 5-parted rotate (sometimes 
reflexed-spreading) corolla, small and fleshy annular or cup-shaped 
crown in the throat of the corolla, horizontal anthers partly hidden un- 
der the flattened stigma and opening transversely, 5 pairs of horizontal 
pollinia, and swollen pods mostly muricate with soft warty projections. 
* Corolla reticulated and sometimes rugulose with a fine network of colored veins ; the lobes 
commonly broad and roundish: crown single. 
1. G. reticulatus Engelm. Hirsute with spreading and reddish bristly hairs: 
leaves deeply cordate with incurved auricles, acute or acuminate: peduncles equal- 
ing or exceeding the slender petiole and sometimes larger than the leaf, 5 to 9-flow- 
ered: corolla lurid green, with purplish venation, glabrous within, hairy without; 
lobes broadly ovate or obovate: crown a narrow entire ring around the base of the 
distinct column: pods strongly muricate. (G. granulatus Torr. Mex. Bound., not 
Scheele. )—Thickets and rocky banks of southern and western Texas. 
* * Corolla not venulose-reticulated (at least not conspicuously) ; the lobes from ovate- 
acuminate to linear: crown simple, unappendaged within: pods smooth. 
2. G. levis Michx. More or less pubescent or hairy: leaves oblong-cordate with 
a deep and narrow open sinus, conspicuously acuminate, 7.5 to 15cm. long: umbels 
5 to 10-flowered, barely equaling the petiole: corolla elongated-conical in bud, not 
twisted; lobes narrowly or linear-lanceolate, obtuse, glabrous inside, 3 or 4 times as 
long as the calyx: crown a low and undulately 10-lobed fleshy disk at base of short 
column.—Extending from the Gulf States into eastern Texas, and passing into var. 
MACROPHYLLUS Gray (G. macrophyllus Mx.), with larger broadly cordate leaves, the 
sinus often closed, finely pubescent beneath. 
3. G. sagittifolius Gray. Barely puberulent, small and low: leaves rather fleshy, 
6 to 12 mm. long, with petiole of half the length, sagittate, with auricles obtuse or 
roundish: flowers solitary and subsessile in the axils: crown at base of corolla, en- 
tire and saucer-shaped.—Mountain sides along the Limpia River. 
