KNOTWORT FAMILY. 359 



# * Flowers white. 



A. fr&grans, Nutt. Stems ascending, branching ; leaves lance-ovate ; 

 flowers sweet-scented, opening at sunset ; the involucre of conspicuous, 

 ovate, scarious and whitish bracts. W. Iowa, W. 



* * * Flowers yellow. 



A. ar en aria, Menzies. Leaves thick, ovate to reniform; plant glandu- 

 lar. Cal. 



2. OXYBAFHUS. (Greek, for a vinegar saucer, from the shape of 

 the involucre.) % Flowers rose-purple, all summer. 



* Plant glandular; leaves sessile or nearly so. 



O. dlbidus, Sweet. S. Car., S.; hairy or pubescent above; leaves 

 acute at base, lanceolate or oblong ; fruit hairy ; stem 4-angled. 



O. hirsutus, Sweet. Glandular-hirsute, especially at the joints and 

 inflorescence, l°-3° ; leaves lanceolate or narrower, cuneate at the base ; 

 fruit with obtuse angles. Wis., S. W. 



* * Plant not, or very little, glandular; leaves distinctly petioled or else 



linear. 



O. nyctagfneus, Sweet. Much branched, l°-3°, nearly smooth; 

 leaves lanceolate to ovate ; inflorescence loose and but slightly pubescent ; 

 fruit acutish-angled. Minn, and Wis., S. ; also cult., and sometimes 



O. angustifdliuB, Sweet. Tall, glabrous, or the peduncles and invo- 

 lucres hirsute ; leaves linear, thick and glaucous, 2'-6' long. Minn., S. 



3. MIRABILIS, FOUR-O'CLOCK or MARVEL OF PERU. (Clu- 

 sius called it Admirabilis, which Linnseus shortened.) Natives of 

 warm parts of America ; roots often very large and fleshy ; leaves more 

 or less heart-shaped, the lower petioled; flowers mostly clustered, 

 showy, opening towards sunset or in cloudy weather, produced all 

 summer. % 



M. Jal&pa, Linn. Common F. Cult, for ornament in many varieties 

 of flowers (red, yellow, white, or variegated), its tube only 2' long, and 

 thickish ; stamens shorter than its spreading border ; whole plant nearly 

 smooth ; inodorous. 



HI. long i flora, Linn. Less common in cult. ; tube of the sweet-scented 

 flower 6' long and clammy-hairy (as well as the upper leaves); stamens 

 shorter than its spreading white border. 



XCII. ILLECEBRACE2E, KNOTWOKT FAMILY. 



Ours small and unimportant herbs, often united with the 

 Pink Family, having mostly opposite and entire, often linear 

 leaves, scarious stipules (0 in Scleranthus), calyx 4-5-toothed 

 or -parted and persistent, stamens borne on the calyx and as 

 many as its lobes (then opposite the lobes) or fewer, styles 2, 

 distinct or united, and utricle 1-seeded. Mowers small, -whitish 

 or greenish ; plants tufted or diffuse ; staminodia sometimes 

 present. 



