ANONACEAE 447 



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8. Thalictrum purpurascens L. Foliage glandular-pubescent or glabrate. Stems 

 stout, erect, 1-2 m. high, leafy, branching above, often purplish : leaves ample ; blades 

 3-4-ternate ; leaflets thick, oblong or obovate, dark green above, commonly waxy beneath, 

 with revolute margins, and 3 main apical pointed lobes : panicle compound, leafy-bracted, 

 3dm. long or more : flowers polygamous : filaments narrow, slightly widened above : anthers 

 linear or linear-oblong, cuspidate : stigma linear, persistent : achenes ovoid, glabrous or 

 pubescent, short-stipitate, with 6-8 longitudinal wings. 



In copses and woodlands, Nova Scotia and Anticosti to Saskatchewan, Florida and Arizona. 

 Spring and summer. 



9. Thalictrum macrostylum (Shuttl. ) Small & Heller. Foliage glabrous. Stems 

 slender, 0.5-1.5 m. tall, striate-ridged : leaves few, the upper cauline, nearly sessile;. 

 leaflets thick, conspicuously small, 5-9 mm. broad, entire or shallowly 2-3-lobed, pale 

 green above, whitish beneath : flowers dioecious or nearly so, relatively numerous : fila- 

 ments spatulate,' about as long as the anthers : achenes oval, 4-5 mm. long, numerous, 

 often 12-24, or sometimes only a few maturing, in dense globose heads, somewhat grooved, 

 each tipped with the stout style. 



In meadows and lime sinks, North Carolina to Georgia and Florida. Spring. 



10. Thalictrum polygamum Muhl. Foliage pubescent or glabrous, never glandular. 

 Stems stout, 1-3 m. high, branching, leafy: leaves ample; blades 3-4-ternate; leaflets 

 moderately thick, light green above and paler beneath, oblong-obovate, or orbicular, with 

 3 main apical pointed or obtuse lobes : panicle compound, leafy-bracted, 3 dm. long or 

 more : flowers polygamous, white : filaments broadened : anthers oblong, short : achenes 

 ovoid, stipitate, 6-8-winged, glabrous or pubescent. 



In open swamps, Labrador and Quebec to Ohio and Florida. 



FAMILY 3. ANONACEAE DC. CUSTARD- APPLE FAMILY. 



Shrubs or trees, possessing a light wood and an aromatic or strong-scented 

 bark. Leaves alternate, without stipules : blades entire, commonly broadest 

 above the middle. Inflorescence terminal, axillary or opposite the leaves. 

 Flowers perfect or sometimes monoecious or dioecious. Calyx of 3 or rarely 2 

 distinct or united valvate or rarely imbricated sepals. Corolla of mostly 6 im- 

 bricated or valvate membranous or thick petals, in 2 series, the inner smaller, or 

 rarely wanting. Androecium of numerous stamens usually crowded on a recep- 

 tacle. Filaments very short, distinct. Anthers extrorse, surmounted by ap- 

 pendages. Gynoecium of few or numerous sessile, distinct or somewhat united 

 carpels. Ovaries 1-celled. Style short, or wanting. Stigma rarely grooved or 

 2-lobed. Ovules anatropous, solitary or few, erect or ascending, or many and 

 horizontal in 2 series. Fruit a more or less pulpy berry derived from one carpel 

 or from the union of many carpels. Seeds flattened, with a parchment-like or 

 crustaceous testa, naked or enclosed in an aril. Endosperm copious, ruminated. 

 Embryo near the hilum. 



An ther-sacs separated : petals imbricated : ovules numerous : fruit simple, from one pistil. 1. ASIMINA. 

 Anther-sacs contiguous : petals valvate : ovule solitary : fruit compound, from the confluent pistils. 



2. ANONA. 



1. ASIMINA Adans. 



Ill-scented shrubs or trees. Leaves deciduous. Flowers perfect, white or purple, 

 axillary on branchlets of the present or preceding year, solitary or in pairs. Sepals 3, 

 valvate, much smaller than the petals. Petals 6, imbricated, the outer spreading and often 

 the larger. Keceptacle subglobose. Anther-sacs separated, adnate to the back of the fila- 

 ments, surmounted by the glandular tip of the connective. Carpels 3-15, distinct, on top 

 of the receptacle. Ovary tipped by a curved style. Ovules numerous, in 2 series, hori- 

 zontal. Berries simple, solitary or several together, more or less elongated. Seeds flattened, 

 with a leathery-crustaceous testa, enclosed in a fleshy-membranous aril, imbedded in a 

 yellowish pulp. Endosperm horny. Embryo with very short cotyledons. 



A. Flowers terminal, or from the axils of the leaves of the season, appearing after the leaves. 



a. Flowers axillary (except rare cases in no. 1), long-pedicelled : leaf-blades long and narrow, linear 



or oblanceolate. 



Mature outer petals 3.5 cm. long or longer, white or yellowish white at maturity. 1. A. angustifolia. 

 Mature outer petals 3 cm. long or shorter, deep black-purple at maturity. 



Petals oblanceolate or narrowly obovate. the outer 2-3 cm. long. 2. A. pygmaea. 



Petals oblong, all nearly alike, 6-8 mm. long. 3. A. Rugelii. 



