82 WILLIAM TRELEASE ON THE 



4. E. ciouTARiUM, L'Her., Ait. Hort., Kew, ir, 414; BreAver and Watson, Bot. Calif. 

 I, 94; Vasey, Rep. Depart. Agric, 1881-2, 253, PI. 22. Loosely white-villous ; leaves 

 oblong, pinnately9-ll-divided; divisions remote, ovate, pinnatisect with oblong or linear 

 sharply serrate segments ; stipules scarious, lanceolate, aciite ; jieduneles about 9-flowered ; 

 sepals about 8 nun. long, mostly abruptly pointed, the awn tipped with 1-2 long Avhite 

 hairs; petals rose-purple, about 5mm. long; beak 30-40 mm. ; divisions of capsule 1X5 

 mm., obliquely truncate; seed .8 X 2.5-3 mm.— Oregon to [N^evada and Texas; also met 

 with occasionally as a weed or ballast-plant elsewhere (Mich., TutJiill, Bailey ; Mass., 

 Murray, Lowell, Oal-es; Maine, Farlow; Xcav York, Kniesl-em, Ilolton; Pennsylvania, 

 Bedfield; Ncav Jersey, Parher; j^cav Brunswick, Hay). Introduced from south Europe. 

 Flowering in dry places when less than an inch high. Relished by cattle, and said to 

 impart a pleasant taste to their milk. — PI. 10, fig. 18. 



So fiir as their vegetation is concerned, the species of Erodium agree in the main with 

 Geranium. As a rule they are less branched. (IS^ote 5.) The inflorescence differs 

 chiefly in that the umbels are more than 2-flowered, and the pedicels are always more 

 or less reflexed during the maturation of the fruit, to become erect, ultimately. 



The flowers are usually turned more to one side when open, than in Geranium, and 

 this change in their position is accompanied by a slight degree of irregularity, the tAVo or 

 three petals on the lower side being larger, by Avhich they are fitted to serA^e as an 

 alighting place for insect visitors — chiefly bees. The flowers are usually distinctly pro- 

 tandrous, and secrete an abundance of nectar. In the main they differ A^ery little from 

 those of Geranium in the Avay in Avhich they are pollinated. E. cicutarium has been 

 shown by LndAvig to be gyno-dioecious. (Note 6.) 



The contrivances for dissemination are even more interesting in this genus than in the 

 last. The fruit is essentially the same in both, the segments of the ovary being ])ro- 

 longed in flat bands that extend along an axile beak and form the styles above. These 

 appendages or awns consist in both genera almost exclusively of mechanical (bast) fi- 

 bres. In Geranium, those forming the outer part conti-act to a greater extent than 

 those nearer the axis, as the fruit ripens, so that ultimately the base of the awn curves 

 outwards in a radial plane, as has already been explained. In Erodium the carpels remain 

 practically indehiscent and are firm and sharp-pointed at the base, gradually enlai-ging 

 upwards, and are covered below with obliquely ascending stiff hairs, supported at the 

 base by firm cells projecting from the epidermis of the ovary. The awn is similar to that 

 of the last genus, but Avhile its outer fibres merely shorten in drying, the inner ones, for 

 the lower half, contract spirally, so that the I'ipened carpel is not only thrown elasti- 

 cally from the plant, but the awn ultimately becomes coiled beloAV into a close helix, from 

 the top of which the upper half bends away in a gradual curve. The awn is also 

 bearded below, on the inner side, and when it at length becomes twisted, the long loose 

 hairs point outAvardly in such a manner as to act in some measure as a parachute, favor- 

 ing the further removal of the fruit by the Avind. 



"When moistened, the awns become straight, resuming their coiled form again when 

 allowed to dry, and repeating these changes with every alternation of moisture and dry- 



