AN ENCYCLOPADIA 
OF HORTICULTURE. 27 
Thermometer—continued. 
a Solar Radiation is specially made for indicating the 
highest temperature in the sun’s rays; and there is also a 
Minimum, for laying on the grass. In all gardens, a 
minimum registering Thermometer is most desirable, for 
ascertaining the lowest degree reached in frosty weather 
during any given period; it should be suspended in a 
position with north aspect, where there is a fair exposure. 
Ordinary Thermometers, if correctly graduated to the. 
scale, are well adapted for all horticultural purposes 
under glass. ` There are also special ones made for use 
in Mushroom-beds, or other places where there is bottom 
heat. 
THERMOPSIS (from Thermos, a Lupine, and opsis, 
resemblance; the species are not unlike Lupines). 
Thermia. ORD. Leguminose. This genus embraces about 
a dozen species of hardy, perennial herbs, natives of 
North America and Asia (Siberia and Himalayas). Flowers 
yellow or rarely purple, rather large, in terminal or leaf- 
opposed racemes; calyx teeth or lobes sub-equal, or the 
two upper ones connate in one; standard sub-orbicular ; 
keel equalling, or slightly longer than, the wings ; stamens 
free; pedicels solitary. Pods sub-sessile or shortly 
stipitate. Leaves .perfectly alternate, digitately tri- 
foliolate ; stipules leafy. The following species have been 
introduced. They are elegant subjects, but rather diffi- 
cult to preserve. They succeed best in a light, rich soil. 
Propagation is most safely effected by means of seeds ; 
for when the plants are separated at the roots, they often 
decline. : 
FIG. 22, THERMOPSIS MONTANA, showing Habit and detached 
lower. 
T. barbata (bearded).* jl. six to twelve, shortly pedicellate, 
Opposite or ternate; corolla deep purple, lin. long. June. 
l. sessile, sub-glabrescent, often opposite ; leaflets oblanceolate ; 
stipules resembling the leaflets both in texture and shape. 
Stems lft. or more high, copiously dichotomously b 
= tock woody. Himalayas, 1854. (B. M. 4868.) 
+ Corgonensis (Corgon). ji. yellow, 
nearly sessile ; aie gmat June and July. 
shortly petiolate; leaflets ovate, acute; sl 
With the leaflets a kind of half-whorl. A. 
Alps, 1820, 
= fabacea (Bean-like). A synonym of T. montana. 
+ lanceolata (lance-shaped). jl. yellow, 
Whorled ; calyx Sieft to the wiadle ; bracts large; racemes ter- 
inal, June and July. 1 nearly sessile, the lower and the 
minal, à 
ighest le; leaflets oblong-lanceolate, silky- 
peas, faa soapie SES ie ty ungth ot aie 
to 2ft. Corgon 
SYN. — 
ranched. 
twin on the racemes, — 
twin or somewhat 
| 
Thermopsis—continued. 
oe Ra Kamtschatka, 1779, Syn. Podalyria lupinoides 
T. montana (mountain).* /. yellow, alternate ; racemes terminal. 
June and July. ¿ petiolate; leaflets broadly oval; stipules 
broadly ovate, obtuse, shorter than the petioles. h, 1ft. to 2ft. 
North America, 1818. See Fig. 22. (B. M. 3611; B. R. 1272; 
L. B. C. 1856.) Syn. T. fabacea. 
T. nepalensis (Nepaul). A synonym of Piptanthus nepalensis. 
, THEROLEPTA. A synonym of Marshallia (which 
see). 
THEROPOGON (from theros, summer, and pogon, 
a beard; in allusion to the time of flowering and the tuft- 
like appearance of the plant). ORD. Liliacew. A mono- 
typie genus. The species is a greenhouse, herbaceous 
perennial, of tufted habit, with grass-like leaves and the 
general habit of Anthericum, of frequent occurrence in 
the Himalayas. The most suitable soil for the cultiva- 
tion of this plant is one composed of sandy loam and 
leaf mould. Propagation may be effected by seeds, sown 
on a hotbed, during spring; or by divisions. 
T. pallidus (pale).* jl., perianth white, sometimes tinged with 
red, three to four lines long, the segments broad, im ted ; 
pedicels solitary ; raceme terminal, loose, 2in. to Sin. 1 ten to 
slender, firm, shorter than the leaves. 
poes glabrous, 
bed, green above, 
twenty-flowered ; sca 
Spring. J. six to eight, nearly lft. long, 
two to three lines broad, distinctly ri 
glaucous beneath. 1875. (B. M. 6154.) 
THESIUM (Thession was the old Greek name used 
by Theophrastus for this or some similar plant; probably — 
derived from Theseus, the legendary hero). Onp, Santa- 
lacee. A large genus (over 100 species) of stove, green- 
house, or hardy herbs, natives of temperate and tropical 
regions: two are found in Brazil; the rest are wholly 
absent in America. Flowers spicate or racemose, or one 
to a peduncle, or forming a compound, cymose in- 
florescence. Leaves alternate, linear, often small, some- 
times reduced to minute seales. A few of the species 
have been introduced, but they are unworthy of culti- 
vation. 7 
THESPESIA (from thespesios, divine; T. populnea 
is frequently planted about churches in the tropics). 
ORD. Malvacee. A small genus (about half-a-dozen 
species) of stove trees or tall herbs, found in tropical — 
Asia, the Pacific Islands, and Madagascar. Flowers often — 
yellow, showy; calyx not conspicuously dotted, truncate, 
rarely five-cleft; ovary five-celled. Leaves entire or 
angular-lobed. Two species have been introduced; both 
are trees. They thrive in a compost of loam and peat. 
Ripened cuttings will root freely in sand or mould, 
under a hand glass, in heat. fii : 
. grandiflora e-towered). Jl. red, 4in. to 5in. in diameter, 
7 pedicels tin long Bcc & go eee? Prag Meio 
acuminate. h. orto Rico, In habit, 
resembles T. populnea. oi sU 
T. populnea (Poplar-like). Mahoe ; Portia-nut Oil-plant; Um- 
. Å at first yellow, with a purple ce 
but changing altogether ria ne Blaeist hord pe off in the 
: ls lłin. to ; 
pio d = l paethe A ar acuminate, five i ae 
nerved, ee Seea with dot-like scales. A. 40ft. Tropics 
of Old World, i 
jm teen ees erg ). Jl, petals narrower than 
7Ps type, orp tour one as tla! long. Cultivated in 
Guadaloupe. 
THEVETIA (so called after Andr. Thevet, 1502- 
1590. a French monk, who travelled in Brazil and 
: ORD. Apocynaceew. A genus embracing about 
eight species of glabrous, stove, American shrubs or small 
Flowers 
throat, the lobes broad and twisted ; 
Leaves alternate, one-nerved or slenderly penniveined. 
Three species are known to cultivation, They thrive 
