172 NYCT AGIN ACE AE (FOUR-O'CLOCK FAMILY) 



3. FROELICHIA Moench 



Erect woolly or silky annuals, with narrow opposite leaves, perfect 3-bracted 

 flowers in panicled spikes. Calyx tubular, 5-cleft at the summit, 2-5-crested 

 on the tube or sometimes tuberculate in fruit. Stamens 5, the united fila- 

 ments forming a tube 5-cleft at summit and bearing the 1-celled anthers be- 

 tween the lobes. Ovary ovoid; the utricle indehiscent and inclosed in the 

 stamen-tube. 



Spikes all opposite 1. F. floridana. 



Spikes alternate, at least in part ........ 2. F. gracilis. 



1. Froelichia floridana (Nutt.) Moq. in DC. Prodr. 13 2 : 420. 1849. Stout, 

 Euberect, with slender branches, 3-5 dm. high: leaves from oblanceolate 

 below to linear on the pedunculate stem: spikes opposite: fruiting calyx 

 vertically wing-crested. From Colorado to Texas and Florida. 



2. Froelichia gracilis Moq. in DC. Prodr. 13 2 : 420. 1849. Similar but 

 smaller and slenderer: leaves linear or the lower spatulate and subpetioled: 

 spikes (at least some of them) alternate: fruiting calyx with vertical rows 

 of tubercles or these confluent into crests. Colorado to Kansas and Texas. 



4. CLADOTHRIX Nutt. 



Low annual, or erect and woody at base, with small rounded entire petiolate 

 leaves. Flowers 3-bracted; bracts concave, hyaline. Perianth of 5 erect equal 

 oblong rigid-scarious sepals, somewhat pilose with verticillately branched 

 hairs. Anthers large, oblong. Utricle ovate-globose, indehiscent. 



1. Cladothrix lanuginosa Nutt. Moq. in DC. Prodr. 13 2 : 360. 1849. Pros- 

 trate or ascending, diffusely branched: leaves round-obovate to rhomboidal, 

 more or less attenuate at base, often in threes: flowers mostly in pairs: sepals 

 twice longer than the broader hairy-tipped bracts. From S. California east- 

 ward through S. Colorado to Arkansas and Texas. 



39. NYCTAGINACEAE Lindl. FOUR-O'CLOCK FAMILY 



Herbs, with stems more or less swollen at the joints and mostly opposite 

 entire leaves. Calyx tubular or funnelform, 4-5-lobed, usually delicate in 

 texture and more or less colored like a corolla, its persistent base constricted 

 above the 1-celled, 1-seeded ovary and becoming indurated into a nut-like 

 pericarp. Corolla wanting. Flowers umbellately clustered and subtended 

 by an involucre (in our genera). Stamens few, slender. Fruit grooved, 

 ribbed or winged. (Allioniaceae.) 



Involucral bracts more or less united. 



Involucre unchanged in fruit . . . . . . . . .1. Mirabilis. 



Involucre accrescent and veined in fruit. 



Involucre 5-lobed . . .2. Allionia. 



Involucre 3-lobed 3. Wedelia. 



Involucral bracts distinct .......... 4. Abronia. 



1. MIRABILIS L. FOUR-O'CLOCK 



Perennial herbs with opposite leaves nearly equal in the pairs. Peduncles 

 solitary in the axils or paniculate. Involucre calyx-like, 5-lobed, not changed 

 in fruit, 3-6-flowered. Perianth tubular-funnelform. Stamens as long as the 

 perianth; the filaments united at the base. Stigma capitate, granulate. 

 Fruit globose to ovate-oblong, smooth or only slightly ribbed or furrowed. 

 (Includes Allioniella Rydb.) 



Inflorescence glabrate . . . . . . . . .1. M. multiflora. 



Inflorescence very glandular pubescent 2. M. oxybaphoides. 



