112 UMBELLIFER^. (PARSLEY FAMILY.) 



5. O. fragilis, Haw. Joints small, ovate, compressed or tumid or even 

 terete, \ to \^ inches long, fragile : larger spines 4, cruciate, mostly yellowish 

 brown, with 4 to 6 smaller white radiating ones below ; bristles few : flowers yel- 

 low : fruit with 20 to 28 clusters of bristles, only the upper ones with a few 

 short spines. — From the Upper Missouri and Yellowstone to New Mexico. 



§ 2. Joints cylindrical, more or less tuberculated : seed not margined. 



6. O. arboreseens, Eng. Arborescent, 5 to 6 feet high (much higher 

 farther south) : branches numerous, verticillate, horizontal or pendulous : 

 joints verticillate : tubercles cristate, prominent : spines 8 to 30, divaricately 

 stellate : berry sub-hemispherical, tuberculate-cristate, yellow, unarmed. — 

 Wisliz. Rep. 6. Abundant from Central Colorado southward. 



Order 35. FICOIDE^. 



A miscellaneous group, chiefly of fleshy or succulent plants, with 

 mostly opposite leaves and no stipules ; difiering from Caiyojjhyllacecs 

 and PortidacacecB by having distinct partitions to the ovary and capsule ; 

 the stamens sometimes numerous, as in Cactacece ; petals wanting in 

 ours. 



1. Sesuvium. Calyx-lobes 5, petaloid. Stamens 5 to 60. Capsule clrcurascissile. Suc- 



culent. 



2. MoUugo. Sepals 5. Stamens 3 or 5. Capsule 3-valved. Not succulent. 



1. SESUVIUM, L. Sea Purslane. 



Calyx-tube turbinate ; the lobes apiculate on the back near the top, mem- 

 branously margined. Styles 3 to 5. Capsule ovate-oblong. — Smooth branch- 

 ing mostly prostrate herbs : leaves opposite, linear to spatulate, entire : flowers 

 axillary and terminal, solitary or clustered. 



1. S. Portulacastrum, L. Leaves linear-lanceolate to oblong-lanceo- 

 late : flowers sessile or pedicellate : calyx-lobes more or less purple : stamens 

 many. — From California through Nevada and Colorado to New Mexico. 



2. MOLLUGO, L. Carpet-weed. 



Stamens hypogynous. Styles 3. Seeds longitudinally sulcate on the back. 

 — Low and much branched, glabrous : leaves spatulate to linear-oblanceolate, 

 entire, opposite and apparently verticillate: flowers mostly on long pedicels 

 and axillary. 



1. M. vertieillata, L. Prostrate: pedicels umhellately fascicled at the 

 nodes: capsule oblong-ovoid: seeds reniform, shining. — From Colorado to 

 Arizona and New Mexico ; also in California and the Atlantic States. 



Order 36. UI?IBELL,IFERiE. (Parsley Family.) 



Herbs, with small flowers in umbels, five epigynous stamens and 

 petals, and two styles ; the calyx adnata to the S-celled ovary, which 



