KNOT WORT 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. arenaria, Menzies. Leaves thick, ovale to reniform ; plant glandu- 

 lar. Cal. 



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

 the involucre.) 2/ Flowers rose-purple, all summer. 



* Plant glandular ; leaves sessile or nearly so. 



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

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



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

 inflorescence, 1^-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. nyctagineus, 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 

 escaped. 



O. angu8tif6lius, 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 Linnaeus 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. 2/ 



M. Jaldpa, 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. 



M. longiflbra, 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. ILLECEBRACE^, KNOTWORT 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. Flowers small, whitish 

 or greenish ; plants tufted or diffuse ; staminodia sometimes 

 present. 



