ON MONOCOTYLEDONOUS SAPROPHYTES. 149 
Contributions to the Knowledee of Mlonoeotyledonous 
Saprophytes. By Percy Groom, M.A., F.L.S. 
[Read 20th December, 1894.] 
(Puates IV.-VI.) 
SAPROPHYTES may be defined as plants which are dependent for 
their existence on the presence in the substratum of decaying 
organic matter. Like parasites, they may be divided into those 
which possess chlorophyll (hemisaprophytes) and those which 
have none (holosaprophytes). 
So far, very few experiments have been conducted on hemi- 
saprophytes ; and we are dependent for our assumption that such 
plants exist upon the fact that in some plants which are always 
found growing in humous substrata the amount of chlorophyll is 
small (species of Corallorhiza ?), or that the allies are bolosapro- 
phytic, or that attempts to cultivate the plants in the absence of 
humus have failed (Cupulifere), or, finally, that peculiarities of 
structure characteristic of holosaprophytes appear in certain 
forms always found in situations rich in humus (absence of root- 
hairs in certain terrestrial orchids and gentians). Thus, our 
acquaintance with hemisaprophytes is largely speculative. And 
the present remarks refer almost entirely to holosaprophytes, or 
at least to plants with scarce a trace of chlorophyll. 
Holosaprophytes amongst Monocotyledons are found only in 
the Orchidacee, Burmanniaces, and Triuridaces *. They are 
all plants characterized by possessing leaves in the form of small 
scales, and a simple undifferentiated embryo. 
Hitherto only a few of these have been investigated as regards 
the histology of their vegetative organs. Schacht and Irmisch 
made some observations on European orchidaceous holosapro- 
phytes (Epipogum, Corallorhiza, Neottia) (1); Prillieux and 
Drude on Neottia (2); Reinke on Corallorhiza and Epipogum (8) ; 
Johow on various Orchidacew, Burmanniaceae, Triuridacez, and 
Gentianaces (4); Poulsen on Triuris and Sciaphila (5, 6). 
Johow gives a complete summary of his own extensive work 
* I think it possible that Petrosavia is a saprophyte, not a root-parasite. In 
this case the Liliacez must be added to the list. 
LINN. JOURN.—BOTANY, VOL. XXXI. M 
