18 ERICACEAE 



Sandhills, 25 to 550 feet : .southeastern Colorado Desert. South to Lower Cali- 

 fornia and Sonora, east to Arizona. May. 



Field note. — Tlie stem descends in tlie sand to a considerable depth, about 2 to 4 feet. In 

 1916 J. Tilley discovered a plant on the Colorado Desert at a point about 20 miles east of Brawley 

 (east of the "East Highline"). He dug down 4 feet, follo\ring the stem, without coming to the 

 root which consists of a mass of fibers wliere attached to the root of the host plant. The stem, 

 chiefly below ground therefore, thickens upward and becomes Yz to 1% inches in diameter and 

 is fleshy. 



The original discoverer, A. B. Gray, found the plant in 1854 w'hilc engaged on a transconti- 

 nental railroad survey. His account of it may be abstracted as follows : The whole plant except 

 the top is buried in the sand. It is very abundant in the sandhills which stretch from Adair Bay 

 around the head of the Gulf of California aud forms one of the principal sources of food of the 

 Papago Indians who eat the fleshy stems boiled or roasted. So prepared. Gray described the 

 freshly cooked plant as "luscious" and resembling in taste the sweet potato, only far more delicate 

 (Ann. Lye. Nat. Hist. N. Y. 8:53-54). Edward Palmer thought the taste of it was like that of 

 the heart of a cabbage (West Am. Sci. 6:137). In California Ammobroma sonorae is a rare plant, 

 but collections have been made at Meloland (Bot. Gaz. 65 : 340), near Hedges Mine, Ogilby {A. L. 

 Stockton), and Grays Well, Algodones Sandhills, ace. Kearney. 



Eefs. — Ammobroma sonorae Torr., Ann. Lye. Nat. Hist. N. Y. 8:52, pi. 1 (1867), type loc. 

 sandhills about Adair Bay, Sonora, Jlex., .1. B. Gray; Jepson, Man. 735 (1925). 



ERICACEAE. Heath Family 



Trees, shrubs or perennial herbs. Leaves simple, alternate in all our genera 

 except four, mostly evergreen and stiff and coriaceous. Flowers white or red, regu- 

 lar aud symmetrical, with the parts in 5s, i-arely in 4s. Calyx 5 (or 4)-lobed or 

 -parted, or consisting of 5 (or 4) distinct or nearly distinct sepals. Corolla sym- 

 petalous, rarely choripetalous. Stamens free from the corolla, as many or com- 

 monly twice as many as its lobes or petals and distinct from them; anthers 2-celled, 

 opening by a terminal pore or sometimes longitudinally, frequently bearing two 

 awn-like appendages. Ovary superior or inferior, 4 to 10 (rarely 1. 2 or 3) -celled, 

 with usually axile placentae bearing numerous ovules. Style 1 ; stigma 1, entire 

 or merely lobed. — Flowers often pendulous. Leaves opposite in Kalmia, Cassiope, 

 Chimaphila and IMoneses. Rhododendron has a slightly irregular corolla, Allo- 

 tropa has none. — Genera 77, species 1400, all continents. 



Bibliog. — MacDougal, D. T., Symbiotic Saprophytism (Pterospora), (Ann. Bot. 13:31-38,— 

 1899). Fernald, M. L., Pyrola asarifolia Michx. var. inearnata (Ehod. 6:178-179, — 1904) ; The 

 Alpine Bearberries and the generic status of Arctous (Ehod. 16:21-32, — 1914). Andres, H., Bei- 

 trage zur Kenntnis der Pyrolaceae (Fedde, Eep. 10:134-144, — 1911). Davidson, J., Newberrya 

 congesta Torr. (First Eep. Brit. Columbia Bot. Office 26-28,-1913). Blake, S. F., Moneses uni- 

 flora var. reticulata (Ehod. 17:28-29, — 1915) ; Variations of ChimaphDa umbellata (Ehod. 19: 

 237-244, — 1917). Dahl, A., Allotropa virgata (Madroiio 1:62, — 1917). Henderson, Margaret 

 W., Comparative study of the structure and saprophytism of the Pyrolaceae and Monotropaceae 

 with reference to their derivation from the Ericaceae (Contrib. Bot. Lab. Univ. Penn. 5 :42-109, — • 

 1919). Jepson, W. L., Pleuricospora fimbriolata in the Santa Cruz Mts. (Nemophila 11 :43-44, — ■ 

 1920); Variation in Hemitomes congestum (I.e. 11:44, — 1920). Wilson, E. H., & Eehder, A., 

 A monograph of Azaleas (Arnold Arboretum Publ. 9:1-219, — 1921). White, P. J., Great abun- 

 dance of pine drops and snow plant (Yos. Nature Notes 9:78, — 1930). Abrams, L. E., The 

 Dwarf Gaultherias in California (Madroiio 2:121-122,-1934). Copeland, H. F., The structure 

 of the flower of Newberrya (Madroiio 2:137-142,-1934); On the genus Pityopus (Madrono 

 3:154-168, — 1935); The reproductive structures of Pleuricospora (Madroiio 4:1-16, — 1937); 

 The structure of Allotropa (Madroiio 4:137-153,-1938). 



A. Shrubs or trees (often small or diminutive shrubs) ; leaves alternate (except in Kalmia 

 and Cassiope); corolla sympetalous (except Ledum). 



Ovary wholly superior. — Subfamily Ericineae. 

 Fruit a dry capsule. 



Anthers awnless; capsule septicidal. 



Corolla with distinct petals; leaves resin-dotted beneath 1. Ledum. 



