ENGELMANN NOTES ON AGAVE. 315 



is the short history of a remarkable species, which will flourish, 

 highly esteemed by amateurs as one of the most striking and 

 beautiful Agaves, and commemorate, among all who love horti- 

 culture in other climes, the name of Henry Shaw, already so 

 highly esteemed in St. Louis as the founder and donor of the 

 "Missouri Botanical Gardens," grand at present, and promising 

 a future as useful as it will be magnificent. 



The trunk of this species is short and globose or more elon- 

 gated, 8-12 inches long, but all covered with its very regularly 

 (in T 8 ¥ ) arranged, broad, deep green leaves, forming masses nearly 

 2 feet in diameter, set off by the large, bright, red-brown spines. 

 Leaves S-io inches long, 3^-4* wide, with a distinct brown 

 horny margin, which bears the unusually large, very close-set, 

 flat spiny teeth, straight, or mostly curved up or rarely down- 

 wards,or flexuous, the largest (near the middle) 6 lines long and 

 half as broad ; in old leaves the margin with a few of the spines 

 adhering, is often partially detached, but not as regularly as e.g. 

 in A. heteracantha. The stalk, 2-2^ inches thick, 8-12 feet 

 high, is almost entirely covered with large (4-5 inches long by 2 

 wide) triangular bracts, foliaceous with brown scarious margins 

 and tipped with a spine. The branches of the broad oval pani- 

 cle are very stout (4-8 or 9 inches long, 1— 1 i thick) flattened 

 above, and bear at the end a most compact cluster of 30-50 flow- 

 ers surrounded by large foliaceous fleshy bracts, 1-2 inches wide, 

 2-3 long, which form a sort of involucre ; the whole, after the 

 flowers have fallen and only the short truncate closely-packed 

 pedicels are seen, interspersed with subulate bracts, 1-2 inches in 

 length, simulates the receptacle of some large Composita, 2-3 

 inches in diameter. 



Flowers 3-3 \ inches long, greenish-yellow; prismatic ovary 

 ii-i£, perigon if -2 inches long, tube outside 8-9, inside 6-7 lines 

 long, lobes 12-14 lines long, outer a little longer and 3§, inner 

 shorter, 4 lines wide. Stamens, inserted in the middle of the tube, 

 only about \ inch longer than perigon ; anthers 14 lines long ; 

 pollen grains oval, 0.09-0.12 mm. in longest diameter, beautifully 

 marked. Style,* in the numerous specimens before me, curved 



* A triangular channel penetrates the style to near its base, where, by salient angles 

 meeting in the centre, the cavity is divided into three tubes, which lead to the ovarian cells, 

 somewhat obstructed, however, about the neck of the ovary by loose cellular tissue. 



