382 FLORA. 



Family 4- N YCTAGINACEAE Lindl. 

 Four-o'clock Family. 



Herbs (some tropical genera trees or shrubs) with simple entire leaves, 

 and regular flowers in clusters, in the following genera subtended by in- 

 volucres. Petals none. Calyx inferior, usually corolla-like, its limb 

 4-5-lobed or 4-5-toothed. Stamens hypogynous ; filaments filiform; 

 anthers 2-celled, dehiscent by lateral slits. Ovary enclosed by the tube 

 of the perianth, i-celled, i-ovuled ; ovule cam pylotropous; stigma capi- 

 tate. Fruit a ribbed, grooved or winged anthocarp. About 17 genera 

 and 250 species, of wide geographic distribution, most abundant in 

 America. 



Involucre of united bracts ; pairs of leaves equal. i. Allionia. 



Involucre of separate bracts ; pairs of leaves mostly unequal. 2. Abronia. 



i. ALLIONIA Loefl. 



Forking herbs, with opposite equal leaves, and involucres in loose terminal 

 panicles. Involucre 5-lobed (of 5 partially united bracts), 3-5 -flowered, becoming 

 enlarged and reticulate-veined after flowering. Perianth campanulate, its tube 

 constricted above the ovary, its limb deciduous. Stamens 3-5, generally 3, un- 

 equal, hypogynous. Fruit obovoid or clavate, strongly ribbed, pubescent in our 

 species. [Name in honor of Chas. Allioni, 1725-1804, a botanist of Turin.] 

 About 20 species, natives of N. and S. Am., one Asiatic. 



Leaves broadly ovate, cordate or oblong-ovate, all petioled. i. A. nyctaginea. 



Leaves oblong or lanceolate, only the lower petioled. 



Plant glabrous or nearly so except the inflorescence. 2. A. albida. 



Plant densely pubescent all over. 3. A. hirsuta. 



Leaves linear, sessile. 



Plant tall, 5-9 dm. high ; branches erect-ascending. 4. A. linearis. 



Plants low, 1-2.5 dm. high, diffusely branched ; branches divergent. 



Involucres axillary, their lobes ovate-oblong, acute. 5. A. Bodini. 



Involucres clustered at the ends of branches, lobes simicircular, obtuse. 



6. A. Bus hi. 



1. Allionia nyctaginea Michx. HEART-LEAVED UMBRELLA-WORT. (I. F. f. 

 1416.) Stem often 4-sided below, glabrous or slightly pubescent, 3-9 dm. tall. 

 Leaves broadly ovate, 5-10 cm. long, acute at the apex, cordate, rounded or trun- 

 cate at the base, all petioled except the bract -like uppermost ones, glabrous or 

 nearly so; peduncles and pedicles commonly somewhat pubescent; involucre shorter 

 than the flowers; perianth red; stamens 3-5, exserted; style exserted; fruit oblong 

 or narrowly obovoid, very pubescent. In dry soil, Minn, to the N. W. Terr., 

 111., La. and N. Mex. May- Aug. 



Allionia nyctaginea ovata (Pursh) Morong. Leaves oblong, lanceolate, oblanceolate 

 or obovate, not cordate ; inflorescence very pubescent. Neb. to Tex. and N. Mex. 



2. Allionia albida Walt. PALE UMBRELLA-WORT. (I. F. f. 1417.) Stem 

 4-sided below, 3-9 dm. tall, the peduncles and branches commonly glandular and 

 viscous. Leaves lanceolate or oblong-lanceolate, 3 -veined, the upper sessile, the 

 lower short-petioled ; involucre much enlarged in fruit, pubescent, ciliate, becoming 

 whitish and purple-veined; perianth pink or lilac; fruit with 5 or 6 obtuse hispid 

 ribs, roughened in the furrows. S. Car. to Mont., Colo., Fla., Mo. and Tex. 

 May-Aug. 



3. Allionia hirsuta Pursh. HAIRY UMBRELLA-WORT. (I. F. f. 1418.) Stem 

 3-9 dm. tall, erect, angled, glandular-pubescent, especially at the nodes, occa- 

 sionally glabrate toward the base. Leaves lanceolate or linear-lanceolate, obtuse, 

 sessile or the lowest sometimes short-petioled, pubescent, 2-8 cm. long; branches 

 and petioles very pubescent; inflorescence usually contracted; stamens often 5; 

 fruit narrowly obovoid, the ribs obtuse. In dry soil, Minn, to the N. W. Terr., 

 Wis., Colo, and Tex. July- Aug. 



4. Allionia linearis Pursh. NARROW-LEAVED UMBRELLA-WORT. (I. F. f. 

 1419.) Stem glabrous, glaucous, 3-13 dm. tall, the branches and peduncl .-s some- 



