RUTACEAE 673 



1. Malpighia glabra L. A glabrous shrub 2-12 dm. tall, with slender branches. 

 Leaf-blades thinnish, ovate, 2-5 cm. long, acute or acuminate, nearly sessile : peduncles 

 0.5-1 cm. long, axillary : pedicels several, umbellately disposed, often longer than_ the 

 peduncles, slender-clavate : sepals ovate, or oblong-ovate : petals rose-red, or sometimes 

 rather pale pink ; blades about as broad as long, 4-6 mm. long, erose or fimbriate : drupe 

 about 1 cm. in diameter, red, the nutlets 4-angled, transversely wrinkled between the 

 crests or ridges. 



In sandy soil, southern Texas and Mexico. Also in the West Indies. Spring and summer. 



3. THRYALLIS L. 



Shrubby plants, sometimes herbaceous above the base. Leaves opposite : blades with 

 2 glands at the base or on the upper part of the petiole. Flowers regular, in terminal 

 racemes. Sepals 5, without glands. Petals 5, yellow or orange : blades finely toothed, 

 distinctly clawed. Stamens 10, all perfect : filaments distinct or nearly so. Ovary 3-celled : 

 styles 3, distinct : stigmas very small. Capsule 3-celled, the carpels separating and dehis- 

 cent. Embryo hooked. 



1. Thryallis angustifolia (Benth. ) Kuntze. Somewhat woody at the base. Stems 

 usually tufted, slender, 3-7 dm. tall, glabrate, or strigose with medifixed hairs : leaf- 

 blades" various, linear to lanceolate, with acute ends, or the lower oblong to oval, with ob- 

 tuse ends and short-petioles, all glabrous or nearly so, glaucous : racemes virgate, loosely 

 flowered : sepals lanceolate : petals yellow turning reddish ; blades oblong-ovate, 2-4 mm. 

 long, with a dark midrib : capsules 3-4 mm. long. 



In dry, usually rocky soil, Texas and adjacent Mexico and in Lower California. Summer. 



4. ASPICARPA L, C. Rich. 



Perennial herbs, more or less woody at the base, commonly diflfuse in habit, sometimes 

 almost twining vines. Leaves opposite : blades entire. Flowers solitary or clustered, dimor- 

 phous, the normal with 5 sepals, 8-20 glands, and petals with fringed blades ; stamens 5-6, 

 2-3 sometimes imperfect ; filaments monadelphous : gynoecium of 3 distinct or partially 

 united carpels ; styles united ; stigma depressed-capitate or truncate. Cleistogamous flowers 

 more fertile than the normal, with glandless sepals and usually a dicarpellary pistil with little 

 or no style, usually maturing one carpel into a triangular nutlet incumbent on the receptacle. 



1. Aspicarpa hyssopifolia A. Gray. Woody at the base. Stems erect, 1-3 dm. 

 tall, more or less pubescent with medifixed hairs : lower leaves with oblong or oval 

 blades, the upper with linear or linear-lanceolate blades 1-3 cm. long, sessile, or nearly so, 

 and partly clasping, all glabrous : flowei-s solitary in the axils of the leaves, the normal 

 with pedicels nearly as long as the leaves : petals 4-6 mm. long ; blades fimbriate : cleis- 

 togamous flowers sessile : nutlets 4-5 mm. long, reticulated, with an acute crest on the back. 



On plains and prairies, southern Texas and adjacent Mexico. 



Family 8. RUTACEAE Juss. Rue Family. 



Aromatic shrubs or trees, or rarely shrubby herbs, often armed with prickles 

 which are sometimes raised on corky ridges. Leaves alternate or opposite : 

 blades simple or pinnately compound : leaflets glandular-punctate, the lateral 

 with inequilateral blades. Flowers usually perfect, in paniculate or corymbose 

 cymes, mostly regular. Calyx of 3-5, or rarely more, imbricated sepals, more 

 or less united at the base, or wanting. Corolla of 3-5, or rarely more, usually 

 imbricated petals. Androecium of as many stamens as there are petals, or 

 rarely thrice as many, inserted on a hypogynous disk, those opposite the petals 

 usually shorter than the others. Filaments distinct or united below. Anthers 

 introrse. Gynoecium of 2-5 distinct or united carpels. Styles more or less 

 united. Stigma often 3-5-angled. Ovules 2, or rarely 4 or more, superposed in 

 each cavity. Fruit capsular, or often a samara, drupe, or berry. Seeds solitary 

 or several, with an often crustaceous furrowed or punctate testa. Endosperm 

 fleshy or wanting. 



A. Fruit dry, capsular or samaroid. 

 a. Fruit dehiscent, a capsule. 



* Ovules 3 or more in each cavity : capsule lobed, solitary. 



Gynoecium 4-5-carpellary : leaf-blades divided. 1. Ruta. 



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