MENTZELIA FAMILY 209 



(2) Spines 1-8, not greatly unlike in length 



(a) Spines twisted, 3-5 O. tortispina 



(b) Spines not twisted, 1-8 



x. Spines 1-3, brownish; joints round to 



obovate O.camdnchica 



v. Spines 5-7; joints oblong O.schwerinidna 

 b. Fruit dry, usually spiny ; flowers yellow or red 



(1) Flowers yellow, spines 8-15 0. polyacdntha 



(2) Flowers red; spines 2-4 0. rhodantha 



2. Joints of the stem flattish to somewhat terete, 



separating easily 



a. Flowers yellowish; joints 1-2 in. long; spines 



usually 4 ' 0. frdgilis 



b. Flowers pink or reddish: joints 2-4 in. long; 



spines 3-5 0. riitila 



3. Joints long, cylindric or angled; stems 2-15 ft. 



high 



a. Plants spreading, about 2 ft. high; edges of 



stem not comb-like 0. Ddvisii 



b. Plants erect, 4-15 ft. high; edges of the stem 



comb-like 0. arbor escens 



LOASALES .MENTZELIA ORDER 

 LOASACEAE MEXTZELIA FAMILY 



Sepals 4-5, united into a long tube, grown to the ovary, petals 4-10 

 on the throat of the calyx, stamens many, inserted with the petals, ovary 

 1-celled, style entire or 2-3-lobed ; flowers solitary or in racemes or cymes, 

 regular, perfect ; herbs with opposite or alternate leaves, usually armed with 

 hooked hairs. 



Mentzelia Linne 1753 Mentzelia 



I Xamed for Mentzel, a German botanist) 



(Touterea E. & YV. ; Acrolasia Rydberg) 



PI. 31, fig. 14; pi. 32. fig. 5." 



Sepals 5, united into a cylindric or club-shaped calyx, grown to the 

 ovary, petals 5-10, crcam-culored u> yellow, stamens 20-many, ovary 1- 

 celled, styles 3, somewhat united, capsule opening at the top, seeds often 

 winged ; flowers terminal, solitary or in cymes ; leaves alternate, entire to 

 pinnatifid; annual or perennial. 



