BUETTNERIACEAE 7 79 



FAMILY 3. BUETTNERIAOEAE H.B.K. CHOCOLATE FAMILY. 



Shrubs, trees or herbs, often resembling Malvaceae in habit. Leaves alter- 

 nate : blades simple, entire or toothed. Flowers mostly perfect, regular, in 

 spikes, racemes or panicles. Calyx of 5 distinct or nearly distinct sepals. Co- 

 rolla of 5 distinct petals, or wanting. Androecium of as many fertile stamens as 

 there are sepals and alternate with them, or numerous : filaments sometimes ag- 

 gregated into groups : anthers with 2 or 3 parallel sacs, opening extrorsely. Gyn- 

 oecium of 5 united carpels or rarely of 1 carpel. Ovary 5-celled or 1-celled. 

 Styles distinct or united. Ovules few or several, ascending or horizontal. Fruit 

 a capsule or follicle. 



Corolla present. 



Petals with flat blades. 



Gynoecium of 5 united carpels : styles 5, not eccentric : stigmas capitate. 



Staminodia wanting : ovules several in each cavity : embryo curved. 1. HERMANNIA. 

 Staminodia present : ovules 2 in each cavity : embryo straight. 



Involucel wanting : capsule pyramidal, loculicidal. 2. MELOCHIA. 



Involucel of 3 or more bractlets : capsule globose, loculicidal and sep- 



ticidal. 3. RIEDLEA. 



Gynoecium of a single carpel : style 1, eccentric : stigma brush-like. 4. WALTHERIA. 



Petals with hooded blades. 



Ovary stipitate : petals appendaged. 5. AYENIA. 



Ovary sessile : petals unappendaged. 6. NEPHROPETALUM. 



Corolla wanting. 7. FIRMIANA. 



1. HERMANNIA L. 



Shrubs or shrubby herbs, with more or less pubescent foliage. Leaves alternate : blades 

 toothed. Flowers perfect, in axillary cymes. Involucel wanting. Sepals 5, nearly distinct. 

 Petals 5, broadened upward : claws involute. Stamens 5, not accompanied by Staminodia : 

 filaments united at the base : anthers sometimes with tapering sacs. Ovary 5-celled : styles 

 nearly distinct, converging. Ovules numerous in each cavity. Capsule 5-celled, locu- 

 licidal. Seeds reniform. Endosperm fleshy. Embryo curved, with narrow cotyledons. 



1. Hermannia Texana A. Gray. Shrubby, 5-12 dm. tall, the foliage tomentose- 

 canescent with stellate hairs. Leaf-blades suborbicular to ovate or oval, 1.5-6 cm. long, 

 rounded at the apex, serrate or dentate, mostly subcordate at the base : peduncles axillary, 

 1-1. 5 cm. long, few-flowered: pedicels shorter than the peduncles, becoming recurvea : 

 sepals lanceolate or triangular-lanceolate : corolla dull scarlet : petals crimson, 7-9 mm. 

 long : capsules globose, short-stalked, 10-12 mm. long, villous-tomentose, each valve with 

 a filiform crest on the back. 



In dry or rocky soil, Texas and adjacent Mexico. 



2. MELOCHIA L. 



Herbs, shrubs or rarely trees, mostly pubescent with stellate and often simple hairs. 

 Leaves alternate : blades toothed. Involucel wanting. Sepals 5, united below. Petals 5, 

 convolute, flat, early withering. Stamens 5 : filaments more or less united into a cup, 

 sometimes with as many tooth-like Staminodia. Ovary 5-celled, sessile or nearly so : styles 

 5, distinct, at least above : stigmas club-shaped. Ovules mostly 2 in each cavity. Cap- 

 sule pyramidal, 5-celled, loculicidally 5-valved. Seeds solitary in each cavity, ascending. 

 Endosperm fleshy. Embryo straight, with broad cotyledons. 



Foliage tomentose : leaf-blades leathery : filaments well united : capsules with rounded basal angles. 



1. M. tomentosa. 

 Foliage glabrous : leaf-blades membranous : filaments slightly united : capsules 



with long-tipped basal angles. 2. M. pyramidata. 



1. Melochia tomentosa L. A branching shrub several dm. tall, the foliage finely 

 tomentose. Stems with relatively stout branches : leaf-blades rather firm, ovate or ob- 

 long, 1.5-6 cm. long, serrate to crenate, mostly acute, truncate or cordate at the base : 

 peduncles several-flowered : pedicels 2-5 mm. long : sepals lanceolate or linear-lanceolate : 

 corolla often rose-purple : petals fully 1 cm. long : filaments united quite high up : capsules 

 about 1 cm. broad, tomentulose, the prominent angles rounded or bluntly tipped at the base. 



In rocky soil, near the lower Rio Grande and in tropical America. 



2. Melochia pyramidata L. A shrubby herb, sometimes annual, the foliage gla- 

 brous. Stems with slender branches : leaf-blades rather thin, ovate-oblong below, oblong- 

 lanceolate above, serrate, mostly rounded or truncate at the base : peduncles 1 -few-flowered, 



